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FAQs on Marine Water Quality involving Phosphates, Sources

Related Articles: Phosphates in Marine Aquarium Systems by Marco Lichtenberger, Phosphates in Carbon; An analysis of the phosphate content of activated Carbon by Steven Pro, Ammonia, Nitrates, Nitrites, SilicatesMarine Chemical Filtrants,

Related FAQs: Phosphates 1, Phosphates 2, & FAQs on Phosphate: Importance, Science, Measure, Control, Chemical Filtrants, Troubleshooting/Fixing, & Nitrates, NitritesAmmonia, Silicates, Avoiding Algae Problems in Marine System, Nutrient Control and Export, Algae Control, Marine Maintenance, AlkalinityChemical Filtrants

Mmm, some source water, live and prepared foods, substrates, decor items, some carbons, salt mixes and supplements... living "things"... can all be sources of phosphate... Oh, volcanoes too.
Mmm, and some HPO4 is necessary for all life

Re: FOWLR Fish stocking 6/1/12   6/5/12
<Hi Bob <<>>, Bobby. Could y'all take a look at this query. Poster is having issues with rocks leaching phosphates.>
Jordan, thanks for the reply and confirmation.
Back to questions on the "cook tank". I just received and used the
Seachem phosphate test instead of the API test and now have a much more accurate reading of phosphates.
I'm dismayed to see that after all the cooking effort, the phosphate level is still between .5-1 mg/L.
<What were the previous measurements? Levels are dropping, correct?>
 This is after a heavy-duty mechanical scrub, 6 weeks of cooking, another heavy-duty scrub and a 100% water change. While I have no intention of doing more than a FOWLR tank, I'm sure I will be in for serious bad algae management issues without a drastic plan. Seems the "old tank rock" syndrome is not always willing to relent without serious measures.
<This is the problem of secondhand rock. You are paying for the previous owners neglect and from what I recall, the rock was in quite rough shape.>
I wonder at this level if a phosphate reactor is even worthwhile.
Seems I could spend hundreds or more on Rowaphos to achieve small ticks down on the phosphate meter over time.
<Bulk GFO will be a cheaper option. Small ticks add up but I agree it is not an acceptable solution at this point.>
So, I am back to square one on plan of attack, and wondering whether I should either a) plan a Rowaphos/reactor approach in combination with macro-algae harvesting,
<I would do both regardless.>
 b) just acid wash the rock and start over, or
<I'm not a muriatic fan; I'm going to defer to another crew member.>
c) continue the cooking for much longer,
<Slow but safe option.>
 or d) ?... I believe Bobby and possibly even Bob weighed in at some point on suggested approaches. Could you mull this over with the Crew, and let me know what you suggest?
<I will send them a copy of your query for their input.>
Re: FOWLR Fish stocking 6/1/12
>    6/5/12
So, I am back to square one on plan of attack, and wondering whether I
> should either a) plan a Rowaphos/reactor approach in combination with
> macro-algae harvesting,
> <I would do both regardless.>
>  b) just acid wash the rock and start over, or
> <I'm not a muriatic fan; I'm going to defer to another crew member.>
> c) continue the cooking for much longer,
> <Slow but safe option.>
>  or d) ?... I believe Bobby
> and possibly even Bob weighed in at some point on suggested
> approaches. Could you mull this over with the Crew, and let me know
> what you suggest?
> <I will send them a copy of your query for their input.>
> <Jordan>
<<I wouldn't acid wash (and rinse, then soak) this olde rock unless you intend to add a considerable (a few tens of percent) of new to inoculate, re-seed the biota that will be entirely eliminated. Have you read here: http://www.wetwebmedia.com/lrselfaq2.htm
and the linked files above? Bob Fenner>>
Re: FOWLR Fish stocking... now HPO4 control  6/5/12

> Bob and Jordan, thank you. It seems the phosphate levels have stayed
> the same despite the measures taken over the last 8 weeks. This is why
> I have given more consideration to the drastic acid route. I would be
> prepared to follow Bob's suggestion on a complete reset/reseed of ~20%
> live rock to start anew.
> I did read/reread the page Bob sent and the linked files, and one
> aspect I previously didn't consider surfaced. The pH consistently
> measures around 7.9 in the dark "cook tank", perhaps a pH adjustment
> may add prevention to phosphate release from the rock? <I would try jacking up the pH to 8.6-8.8 via Kalk... and see if this helps>Do you think
> this plus bulk GFO plus other measures (skimming/macroalgae) would
> yield a continued noble but fruitless run?<I am not a fan of GFO... much more so Lanthanum> I just wonder if more
> time/$ will not help me achieve a more acceptable continuous phosphate
> range.
> Ye Olde Tanke Rocke!!
<... Best of all is a long term, "holistic" approach, using macrophyte et al. culture, as large a DSB as possible... perhaps Ozonation... B>
Re: FOWLR Fish stocking 6/1/12   6/5/12

Bob and Jordan, thank you. It seems the phosphate levels have stayed the same despite the measures taken over the last 8 weeks. This is why I have given more consideration to the drastic acid route. I would be prepared to follow Bob's suggestion on a complete reset/reseed of ~20% live rock to start anew.
I did read/reread the page Bob sent and the linked files, and one aspect I previously didn't consider surfaced. The pH consistently measures around 7.9 in the dark "cook tank", perhaps a pH adjustment may add prevention to phosphate release from the rock? Do you think this plus bulk GFO plus other measures (skimming/macroalgae) would yield a continued noble but fruitless run? I just wonder if more time/$ will not help me achieve a more acceptable continuous phosphate range.
<I yield to Bobs response.>
Ye Olde Tanke Rocke!!

Tufa Rock and Hair Algae 3/1/12
Hi Crew,
<Hello Rebecca>
So I see on previous posts that Tufa rock seems to be implicated in some cases of hair algae troubles. What exactly is it about Tufa that could contribute to more hair algae growth than what you would get with other rock?
<Depending on where it formed or where it was collected from, Tufa rock may contain  significant detrital components along with phosphorous and can be problematic re nuisance algae growth.  Best not to chance it.>
<You're welcome.  James (Salty Dog)>
Rebecca Bray

Rinsing Frozen Food (Managing Phosphate) -- 04/06/10
I have been having a bit of a struggle maintaining a low phosphate level. I even have a phosphate reactor and it's difficult to stay below 0.5.
Most of the time it's right at the 0.5 level -- unless I have recently changed the media. Then I can get 0 to 0.25 for a week.
<<Then this would seem to dictate the frequency at which you need to swap out the media (yes'¦expensive)'¦it may also indicate the reactor is 'undersized' for your system>>
I only use RO/DI water and test it to ensure the filters are doing the job.
<<Very good>>
Could it be that I am introducing phosphates as I feed frozen Mysis shrimp?
I don't do anything special -- just add tank water to thaw the cubes
<<This is what I do as well>>
and then feed with a turkey baster.
<<Some authors consider the thaw-water for frozen foods to be 'rocket fuel' for nuisance alga and the like due to the high nitrate/phosphate content. How much of this 'fuel' is present is likely variable among the differing manufacturers/brands available. The only way to truly know 'if' or 'how much' will be to test for such'¦but yes, the thaw-water is very probably a source of phosphate to your system. Try 'rinsing' for a week and see how this affects your phosphate level>>
Thanks for your comments.
<<Quite welcome'¦ EricR>>

Re: Rinsing Frozen Food (Managing Phosphate) -- 04/06/10
Thanks, Eric!
<<Quite welcome, Gene>>
I finally discovered how to research a topic before sending you guys an email.
Sorry for the lack of research on my part. I found an article on your site that addressed this very question. I imagine it would be difficult to ask a question ya'll have not already addressed.
<<Indeed'¦at least in some form/manner or another>>
Nonetheless, I appreciate your thoughtful response.
<<Always happy to share, mate'¦ EricR>>

Phosphate And Nitrate In Live Rock 1/13/10
Hello crew,
<Hi Carrie>
I currently have a 75 gallon tank with 100 lbs of live rock, the large CPR HOB refugium with Chaeto, and a Remora Pro Skimmer. I made the mistake of using tap water for the first year of having my aquarium, and now I have water quality issues. I have always done a weekly 10 gallon water change, not realizing I was only making the problem worse.
<Actually depends on the quality of your tap water. Our tap water is of good quality and is all I've been using for years.>
I bought a RO/DI unit and continued my water changes and I have done three 50 gallon water changes in the past two months to lower nitrates and phosphates.
<Have you ever tested your tap water for nitrate and phosphate?>
Not surprising, I have a horrendous hair algae outbreak because of these issues. I don't believe I am overstocked, other than needing a larger (6 foot) tank for my tang, which is planned for tax refund time.
<I'll likely buy the IRS a 6 foot system.>
Ocellaris Clown
Onyx Ocellaris Clown
2 Green Chromis
Lawnmower Blenny
Fusi Gobi
White Cheek Tang (A Japonicus) -
Electric Blue Hermit
10 small hermits
3 turbo snails
Fuzzy Chiton
10 Ceriths
Frogspawn - not extending
Galaxea - extending fine
Zoanthids - not extending
Salinity 1.025
PH 8.0
Temp 79
dKH 11
Ammonia 0
Nitrite 0
Nitrate 40 (topped out at 180)
<Yowsa, much too high for a reef tank.>
phosphate .5 (topped out at 5)
calcium 500
2X 175 Watt MH lighting on 8 hour timer.
Please forgive the overflow of information, but I wasn't sure what all you would need.
<Is just fine/useful.>
After spending several weeks reading, I cannot figure out if live rock and sand will continue to leech nitrates as well as phosphates into the water after the problem is removed.
<Nitrates are formed by denitrification, the rock doesn't "leach" nitrates.
Phosphates are present in many fish foods and is leading me to believe overfeeding may be causing your high nitrate level. Depending on the size of your tang, overstocking may also be a contributing factor. Do read here and related articles/FAQ's
Also, my sand bed is about 3 inches, so I believe it is in the gray area that could be contributing to the nitrates.
<Likely a nutrient trap if no beneficial fauna is present in the sand.>
I was considering lowering the sand to one inch, but am concerned about trapped gasses. What is the safest way to remove sand?
<Siphon out during water changes until you get it down to your goal.>
As always, thank you for the advice.
<You're welcome. James (Salty Dog)>

Phosphate -- 09/26/09
Hello Crew,
<Hi Becky.>
I've had a FOWLR tank for 5+ years. It has always has high PO4 and NO3. I just started using RO/DI water about two months ago. I have changed the tank water a few times over by now. It's a 155g. The NO3 is the lowest it's ever been at 20ppm. The PO4 is reading 1 on the Salifert test. It used to be greater than 5! Anyways, my question is, could is be possible that my live rock has "absorbed" a high level of PO4 from being exposed to it for such a long period of time at such a high level?
<Yes, live rock and substrate now might contain inorganic and organic phosphate compounds that can in part be brought back into solution by biochemical activity. You may want to export the phosphates with time by various means. Please also see http://www.wetwebmedia.com/ca/volume_5/volume_5_3/phosphates.htm .>
Thanks, -Becky
<Cheer. Marco.>

Phosphate & Stocking question: Phosphate\nutrient\algae control and stocking SW 8/30/3009
Dear WWM Crew,
<Hi Jan.>
As always, thank you for your great site. Over the 4 years that we have had our reef tank your help and advice has been invaluable!
<Thank you for the kind words.>
Our tank setup is as follows:
- 75 G Oceanic reef ready bow front with a 20 G Eco Systems refugium, about 80 lbs. of live rock.
- Water quality: 77.5 degrees F, 1.025 SG, 8.3 pH, 5 ppm Nitrate, 0 ppm Ammonia & Nitrite, 420 ppm Ca, 1470 ppm Mg, 7.0 dKH and 1 ppm PO4.
<High phosphate, but you already knew that...:) >
- 15% water change every Friday using RO/DI water with 0 ppm readings on the meter.
- 3 feedings per day with a mixture of liquid, frozen & dry foods.
<Ding! we have a winner.>
- Livestock: 2 clownfish (A. ocellaris), mated and spawning
1 Yellow Tang (Z. flavescens)
3 Blue-Green Chromis (Chromis viridis)
3 Peppermint Shrimp (L. wurdemanni)
2 Cleaner Shrimp (L. amboinensis)
2 Fire Cleaner Shrimp (L. debelius)
5 blue legged hermit crabs
Various corals.
<A reasonably stocked tank.>
I have two areas where I need your advice (without which, I am reluctant to do anything in this tank).
<Fair enough.>
1. High phosphate level. Due to ???.
I'm getting a PO4 reading of 1 ppm (confirmed with 2 different test kits) which I understand to be very high. I am experiencing some hair algae growth and CBA (CBA mainly in the refugium). I use RO/DI water (which I have tested a 0 ppm PO4) and I have tested the new salt water before the water change at 0 ppm PO4. The substrate is about 2 to 3 inches deep.
All of the corals are healthy and growing. I do not now where the PO4 is coming from (the substrate?) or how big a problem this is. So, I'm confused and could use some advice.
<Two possible causes - 1st, how much are you skimming out of this tank?
Your skimmer could be undersized. 2nd: Three feedings a day is excessive, especially with liquid foods - those should be used no more than once or twice a week.
we tend to overfeed these because it is a liquid.>
2. Stocking question. Should we add a "Lawnmower" Blenny (S. Fasciatus), or not.
<I wouldn't, you are reasonably stocked now, adding anything else will be pushing the limits.>
Recently, after 3 years of healthy living, our Mandarinfish (Synchiropus splendidus) died. We intend to replace him with another Mandarinfish.
<Do give the pod population time to replenish itself before adding another.
75 gallons is on the edge of being too small for a Mandarin. They need a large tank with a healthy pod population.
http://www.wetwebmedia.com/mandfdgfaqs.htm >
We would also like to add a "Lawnmower" Blenny (S. Fasciatus) but have some concerns. In researching this fish I understand that they can be quite territorial, even belligerent.
<Yes they can: http://www.wetwebmedia.com/blencompfaqs.htm >
Given that we are going to have a Mandarinfish and that our clownfish have taken up residence in a Zoanthid coral on the bottom, right corner of the tank, should we add the Blenny? The thought of a bullying Blenny bothering the clownfish in their little home is untenable. But we need an algae eater and I love the way these crazy looking "Lawnmower" Blennies look.
<You already have a voracious algae eater in the Yellow Tang. Between phosphate control. removing any that is in danger of covering\damaging any corals, and the tang, the hair algae will quickly be under control. Adding a phosphate reactor or just using some Polyfilters can help speed the process up.>
Thanks for your thoughts!!
<My pleasure.>

Re: Phosphate & Stocking question: Phosphate\nutrient\algae control and stocking SW 8/30/3009
Hi Mike,
<Hi Jan.>
Thanks so much for your quick response! However, I have a couple of follow up questions.
1. Are you saying that the PO4 is in the food or that we're putting too much
food in the tank, or both?
The liquid foods we use are made by Reef Nutrition.
<A good brand.>
We use their Phyto-Feast, Oyster Feast & Arcti-Pods. The first two are for the corals. The frozen foods are made by Bio-Pure and we vary the types between feedings. Also, it was my understanding that 3 light feedings per day was ideal. Wrong? If so, what would you recommend?
<Unless you have a fish with a very particular diet, once or twice a day is fine. The fish will graze the rest of the day.>
By the way, the skimmer that we use is the one that came with the Eco-Systems refugium that was specified for this size tank, so I hope that's not undersized.
<Should be fine - are yo getting a lot of skimmate?>
2. Regarding the stocking question, if we decided not to replace the Mandarinfish, would the Lawnmower Blenny be OK? Our Tang, while it does peck at the rock, couldn't be described as a voracious algae eater (at this my wife says maybe because we're overfeeding!).
<Perhaps - tangs love hair algae - at least mine did.>
There seems to be plenty of algae on the rock (not hair algae!). My initial concern about adding this fish was potential aggression towards the clownfish. Or is six fish enough
for a 75G tank?
<6 is about the limit for a 75.>
Once again, thanks for all of your help!!
<My pleasure.>

Hair Algae and it's "Nemesis"?!?   8/24/09
Greetings to my favorite people at WWM!
<Hello to you Jamie>
Interesting observation that I like to share with you. I currently have three tanks. Their parameters are all very similar as I use the same RO water mixed with Coralife Reef Salt and I perform a 15% water change on them every week. There are only TWO differences (Okay, I'm painting with really broad strokes!) - they are the inhabitants and the presence or not of CARBON in the filtration system.
<Mmm... often there are other more subtle diff.s, but let's see...>
Tank 1: Carbon; Green Spotted Mandarin Goby, Barnacle Blenny, Eyelash Blenny, Yasha Hase Goby, Pistol Shrimp, Peppermint Shrimp, Skunk Cleaner Shrimp plus Hermit Crabs.
Tank 2: NO Carbon; Flame Angel, Bicolor Blenny, Black Percula Clown plus Hermit Crabs.
Tank 3: Carbon; Rainbow Fairy Wrasse, Flame Hawk Fish, 2 Pajama Cardinals, Lawnmower Blenny, Pink Spotted Watchman Goby plus Hermit Crabs.
Tank 1 and 3 have been infested with hair algae over the past 4 months.
Tank 2 have consistently been without hair algae or slime algae, not even a hint!
All tanks have been set up for more than one year and I do the same routine for all three tanks, feeding in the same fashion. Tank 2 is the "cleanest", absolutely no signs of hair algae and the tank has a general clean
appearance - minimal detritus on rocks and macro algae where the other two sometimes get that dirty, ash covered look and lots of stuff to blow off during my weekly water changes.
For several weeks, I was thinking that maybe the carbon was leaking something back to the tank to encourage algae growth, but I renew them with fresh carbon every two weeks, so maybe just the presence of carbon... Then today I did an experiment during my weekly water change. I took a green hair algae and red slime algae covered water return from Tank 1 and swapped it with the coralline covered one from Tank 2. Within five hours, that return is cleared of all green hair and red slime algae! Yippi! Well, now, I'm guessing that one of the inhabitants in Tank 2 is having a feast eating this stuff, I just can't decide if it is the Flame Angel or the Bicolor Blenny.
<Could be both, either>
My bet is the Bicolor Blenny but the Flame Angel is the one showing most interest. As I'm writing this, I placed a piece of hair algae covered Zoanthid in the front...I want to watch nature in action, and so far, the
Flame Angel is the one showing interest.
Thank you, each and every one on the WWM team, for creating this site that helps all of us fish lovers to not only learn about the wonderful creatures that we share our earth with, but also encouraging sound stewardship to these wonderful creatures!
Jamie Barclay
<May, might I suggest an experiment with the carbon? Do soak some bit, a tablespoon or so, in a jar of your RO water for a day or two and test for soluble Phosphate... Some "brands" do leach this often rate-limiting noisome algae nutrient. Cheers, Bob Fenner>

Re: Hair Algae and it's "Nemesis"?!?   8/24/09
Dear Bob,
Thanks for your reply. I will definitely do this carbon experiment and keep you updated!
<Thank you Jamie>
I checked my made up water parameters yesterday for phosphate (0),
<Can get "sucked up" by fast growing algae in short order>
nitrite (0), and pH (8.0) prior to using it as I thought maybe my drinking water RO system's filters need changing.
<Perhaps... the pH should definitely be lower...>
The piece of green hair algae covered Zoanthid I placed in Tank 2 is 40% "cleaner" this morning but I think that who ever is eating it is having a hard time pulling the hair algae off as the small piece of rock will move
which-ever direction.
Thank you all, again!
<Pip pip! BobF>

Re: Hair Algae and it's "Nemesis"?!?   8/28/09
Hello Team at WWM!
<Hi there Jamie!>
Hope all is going well for you!
An update. I've soaked some charcoal in my fresh made up water for 48 hours and checked the phosphate level - it is 0.
<I see; thanks>
So, at least I know that my salt is not leaching phosphate into the tank.
<Mmm, the salt mix, synthetic actually may be a/the source here. I would test it as well>
Now, the piece of algae covered Zoanthid I placed in the tank still has green hair algae on it, it is maybe
50% gone now. Humm, this sort of throws things off a bit on my theory.
I've glued that piece of Zoanthid onto one of the largest rocks in that tank...I just hope that I didn't introduce hair algae in there!!![?]
<Some such material comes/goes in every bit of water... via spores in the air if nothing else... It's the conditions that need to be monitored, controlled>
I will keep observing my tank parameters and fish behaviors and keep you updated!
Thanks so much!
<Thank you. BobF>

Should I rinse frozen food to remove phosphates? 8/2/09
<Hi Jim, Jessy here>
I'm hoping you can help resolve what has become a HUGE disagreement between my wife and I. We have two tanks: one 65 gallon that houses our seahorses, that we've had for about three years, and one 210 gallon fairly new reef tank with numerous fish (9 chromis, 2 clownfish, 1 flame Hawkfish, 1 yellow tang, 1 lawnmower blenny, 1 rusty angel, and 1 Banggai cardinal) established about 3 months ago. The seahorse tank has a chronic massive problem with nuisance hair algae. I very much want to avoid having this same problem with the reef tank. Both tanks are regularly fed various frozen foods:
San Francisco Bay brand Marine Cuisine, Spirulina- and Omega3-enriched brine shrimp, and various brands of frozen mysis. The fundamental question that is the basis of our disagreement is whether or not it is important and beneficial to rinse these frozen foods after thawing them. As the person who has to clean the algae from the glass, rockwork, and every other surface of the seahorse tank, and the person who does all of the testing for nitrates and phosphates, and regularly replaces the phosphate adsorption media, I maintain that it is important to rinse the thawed frozen food in order to remove as much phosphate as possible before feeding the fish and seahorses. As the person who regularly feeds the fish and seahorses, my wife maintains that the "juice" from the frozen food contains important nutrients, and that rinsing the thawed food would remove essential nutrition that was specifically added by the manufacturer for the benefit of the fishes and other filter-feeding creatures in the tanks. We recently asked the local "expert" at our LFS, who said he personally doesn't rinse these types of frozen foods, because it helps feed the filter feeders. I'm hoping that you can help settle this disagreement we're having. I've been unable to get my wife to take the time to actually read the numerous sources I've located online, all of which state the importance of rinsing thawed frozen foods to remove phosphates. What does wetwebmedia.com have to say on this issue? To clarify: not asking for marital advice, just whether to rinse or not to rinse!
Thanks in advance,
<Absolutely yes, you should be rinsing your frozen food. You can do something as simple as putting it in a brine shrimp net and holding it under cold tap water to thaw and rinse it at the same time. The things that
you are rinsing off are mostly the binding agents for the frozen food... and yes it can lead to phosphate problems. Your filter feeders will benefit much more from a dose of phytoplankton or Cyclopeeze than they will from the little particles found in that frozen mush. I'm a huge proponent of PE Mysis, (who also suggest to rinse their product) and I noticed that a lot of the pieces and parts that get rinsed off are the lighter scrap, like tails and legs. When added to the tank, none of the fish even attempt to eat those pieces, passing them by for the meaty portions. I said all that to say, that by not rinsing you're putting unnecessary binding agents in your tank and particles of "food" that are just going to go unused and add to a high nutrient problem. By the way, with the hair algae the best way to combat it is to remove it with your fingers (yes elbow grease is
unavoidable) and I've always had success with large turbo snails. Every time you walk past the tank and they are not eating a patch, just pick them up and plop them on top of it. With continued water quality monitoring and a little bit of time, every hair algae problem treated that way has been solved for me. Now Bryopsis, is a whole other ball of wax. Make sure you're identifying it correctly. Hope that helps. Jessy>

Re: No question just thanks... Follow on... Chalk as base rock -- 05/27/08 Hi crew <Hello Garry.> Sorry just sent an Email to Bob and somebody has just asked me a question which I have no answer for, and I wondered if you guys could come up with an answer. <Sure.> Local to where I live we have cliffs of Chalk rock (just like the White Cliffs of Dover) <Nice, I'm a geologist.> being that they are 99.97 to 99.99% pure very soft (for rock anyway) Calcium Carbonate, would it be possible to use this as a base rock for a Reef aquarium. <I would not do that. These rocks (if comparable to Dover) consist of the skeletons of green algae and to a minor extent of foraminifera, ostracods and some molluscs. Whenever sedimentation stopped due to various reasons the sediment layers were in part encrusted with phosphate minerals (the natural way of removing phosphates from the water), which while being pretty much dissoluble in water can easily be dissolved with the help of the life in a reef tank. Phosphates inhibit the growth of the corals' skeletal elements, obviously stony corals are more sensitive. Even if phosphate composes only 0.01-0.03% of the rock (while possible, these numbers seem low to me) and 10 kg (about 20 pounds) are used you'll have a phosphate reservoir of a little less than 1-3 grams. Depending on the specific solution kinetics in your tank this may inhibit stony coral growth. This problem occurs with a lot of calcareous rocks used as base rock.> From watching the effects of the local sea water on the rock pools there is always a degree of erosion and solubility (the water has a slightly milky look) and if this was filtered out would the effect of this rock be beneficial upon pH, calcium content etc. I have done some research into this type of limestone and it is very porous with millions of channels holes etc all the way through it so from the point of view of bacterial "infestation" it seems an ideal base rock, especially as it can be obtained in a very clean non polluted form Anyway your thoughts etc would be appreciated. Garry (in the UK). <In my opinion and experience no rock compares to the real thing re denitrification: live rock. Maybe if put into natural tropical water other porous rocks like the ones you consider might develop similar characteristics, but it will take months at least and is rather unlikely to happen in an aquarium to the same extent it can happen in nature. If you still wish to use the chalk be prepared to also use some phosphate adsorbing media in the future. Cheers, Marco.>

Re: No question just thanks... Follow on 5/27/2008 Hi Marco <Hello Garry.> Thank you for your reply (it's nice to meet another ologist - I'm an Ecologist ). Your reply makes sense to me, however, the percentages of Calcium Carbonate are correct (please read Ecology of the English Chalk by C.J.Smith pub: Academic Press Inc. (American publication) pages 1-17). According to this book and several others the composition of English Chalk is Calcium Carbonate 97.89% <I can agree with that. The last mail spoke of 99.97-99.99, which makes a difference with regard to phosphates.> Magnesium Carbonate 0.75% Silica 0,65% Calcium Phosphate 0.22% <My original calculation was for only 0.01-0.03%. So with this more exact number 10 kg (about 20 pounds) of chalk will introduce a little less than 20 g of phosphates into the system! A concentration of only 0.3 mg/litre, which can easily be reached with this rock and a little time, can seriously inhibit stony coral growth.> Iron oxides 0.14% Water (combined) 0.35% Work done by Dr N.Walsh (sorry not sure when or where published) showed English Chalks to have a purity of between 96.77% and 99.09%. But hey I'm getting pedantic here. <You are not being pedantic at all, these numbers are very useful and as you see one digit here and there makes quite a difference. It's ten times the amount of Phosphates, that's not pedantic.> I agree that the only real rock suitable for Reef aquaria use is or should be Live Rock but we pay a lot for a very little here in the UK (try fuel at over $12 a gallon) and I guess we have to try and spread our costs whilst still providing the absolute best conditions for whatever we keep in those little (or not so little) glass or acrylic boxes in our homes. <I totally agree with you here (I'm in Germany and our gasoline and live rock prices are practically the same as in Britain. I used various types of rock as base rock, too, but often ended with serious phosphate problems when growing stony corals and sensitive soft corals. Those problems had to be addressed with phosphate adsorbing media and water changes, which also cost some money and should to be considered. For fish only tanks it does not matter too much, just less denitrification. For coral tanks I often use "second hand live rock" from well running systems with low phosphate concentrations as a cheap alternative when some hobbyist is giving up due to whatever reason, it typically costs about 1/5 - 1/3 of the commercially sold rock and often has already some soft coral growth.> Your comments have been noted and I will pass them on. Cheers Garry. <Happy reefing! Marco.>

Re: No question just thanks... Follow on... Chalk as base rock III -- 05/27/08 Hi Marco <Hello Garry.> Well, that will annoy my friend who thought he had a cheaper alternative to second hand base rock (he has a garden full of it with a small cliff (the garden was part of an old quarry) I will pass your comments on and await the results of his deliberations, no doubt he will go the live rock route but I think he is aggrieved at the cost. Personally I would pay whatever I had to get the results I would want but this is an expensive hobby (lifestyle?!) and for some the price can be just too much. <I totally agree with the above.> Can I say that if you are German by birth, your English is very very good, <Thank you very much, I'm trying.> and I appreciate your time and energies confirming what I knew but could not convince my friend of. Happy Reefing to you Garry. <Cheers, Marco.>

Rock Leaching Phosphate, Is It Harmful To Fish?...And...After 8-Weeks Fallow, Will My Ich Return? -- 01/12/08 Hey Eric! <<Hey Don!>> Hope all is well with you. <<Not so bad'¦ Currently devoting most all my free-time to a very large renovation/remodeling project'¦can't say I won't be happy when it's done>> I have a question about live rock and phosphates. <<Okay>> I bought some base rock cheap, covered in coralline algae, and I know it's been in the tank for over a month being kept with fish and other animals but they told me that I wouldn't want it cause it leeches phosphates. <<And yet you bought it anyway [grin]>> They told me it was cured so I took it and put it in quarantine and I haven't gotten any readings of phosphates. <<Very good>> Would the rock after being cured be o.k. to put in the main tank or does certain rock always leech phosphate? <<Most any rock can be a source of soluble Phosphate'¦but your tests seem to bear out that this rock will be fine>> Also do phosphates kill fish? <<Hmm, I suppose there's a limit where it could. But in my experience with systems with very high Phosphate levels the fish did not deem bothered directly>> I never had a problem with it and tried to read as much as possible but there were no FAQs that I could find about it. <<Mmm'¦a 'quick' search turns up nothing specific to this for me either. If I am off track/if more need be stated, I trust Bob will interject>> I finally put the fish back in the 210 after 8 week quarantine. <<In regards to your Ich issue, yes'¦excellent>> What are the chances of the main tank and fish being 100% cured because after this live rock is done I was thinking of Hippo Tang to put in the quarantine but if it's not likely 100% then I'll probably not bother with tangs. <<The eight-week quarantine/fallow period will go far towards achieving an 'Ich-free' environment'¦for a time. But as I think I have mentioned before'¦ This protozoan pest is so 'easily' introduced, even from non-organic and non-fish sources (e.g.- live rock, inverts/corals'¦even from using a net from another tank) that it is not realistic to expect to 'never' see it crop up again. Thus the importance to continue with proper quarantine, proper stocking levels/environmental conditions, biological controls (e.g. - cleaner shrimp/gobies), et al. With these considerations, I see no reason to 'stay away' from tangs'¦though I might consider a different specimen from the large and very 'twitchy/nervous' species you have selected'¦perhaps Acanthurus japonicus'¦or one of the commonly available Ctenochaetus species>> I really don't want to break down a 210 tank again! <<I'll bet!>> Thanks again. <<Always welcome>> Any chance of you going to MACNA? <<Indeed'¦have already made reservations and payment to attend>> I was thinking of going to Atlanta in September to go. <<Perhaps I will see you there>> Talk to you soon. Don V. <<Cheers mate. EricR>>

R2: High pH And Hair Algae -- 11/17/07 Hi there again! <<Hello Kerstin>> Well, I hope we're making progress on her tank...I want to keep you updated, and I want to ask some questions as well. <<Cool'¦okay>> I think I may have figured out where the phosphates come from - tell me if you think I might be right. <<Alrighty>> I have made several batches of coral/reef food, using Eric Bornemann's recipe as a base. Included with the fresh seafood and ground up flake food and other assorted stuff are also frozen Mysis shrimps, daphnia, etc...all aquarium packs. <<Okay>> If I am supposed to rinse them before feeding them on an individual cube basis to get rid of the packaged water (I read it's a good source of phosphates), and I did not even thaw them before integrating them into the new mixture, then could that be the source of the phosphates? <<Is probable, yes>> Just a thought, because I can't see where else they might come from. <<Let's test and see to be sure, shall we? Thaw a chunk of the food preparation in a small container of tank water (just like you do when you feed) and then test that water for Phosphate. If there's a chance a chance the tank water will skew the test, then test 'before and after' adding the food stuff>> re the new skimmer - she started running my AquaC skimmer -- <<Excellent!>> collected 1/2 of a cup of "guck" the first night alone...she is absolutely happy that it's pulling this stuff out. <<Is helping'¦that is a certainty>> Between that, having a Poly-Filter pad in her little AquaClear filter, and the fact that she pulled quite a bit of the hair algae wherever she could, we'll see how her tank does...she really appreciates all the suggestions and is happier about her tank already. <<Very good to know>> Although, interestingly enough, when she tested her water in the evening after lights had been on all day (has done 3 5-gallon water changes in the last week), her pH is still running 8.8 - but it is staying stable, so is it something to worry about, or will it drop as the skimmer removes stuff from the water (don't know how that would happen)? <<The skimmer is not going to drop her pH'¦and yes, this reading if accurate is too high/worrisome. I seem to recall you stated before that you have validated this reading with more than one brand of test kit'¦if not please do so. Else'¦it is important to find and remedy the source/reason for this high pH reading (source water is prefiltered, yes?). Do revalidate the salt mix used'¦and stop adding any buffers if using these. And do make sure there isn't an unusual item/tank decoration that has been added to the tank that may be leaching/causing this spike in pH>> Thanks again for all your tremendous help, and we'll let you know what happens. <<Happy to assist'¦please do fix/let me know how things progress re the pH issue>> One positive thing <<Hey'¦I counted more than one! [grin]>> - I gave her a copy of CMA, and am loaning her fish books - she is going to research more on her new tank inhabitants once this problem is solved, since she has already decided to return the lawnmower blenny to the LFS to trade against something else. <<Very good'¦and do lead her here/to this site and teach her how to do keyword searches using the Google search tool>> Thanks, and I hope you're having a lovely weekend, Kerstin:-) <<Weekends are 'always' good, mate. Eric Russell>>

Phosphate Leaching In Plastic Storage Vessel? -- 10/22/07 Hi Guys, <<Peter>> I recently bought a 30 gal plastic container from Lowe's. I started using this to store saltwater mixes for water changes. I have noticed that when I do phosphate tests on the water in the storage bin that phosphate levels up to 5 ppm are detected. The water used is from an RO/DI that gives a TDS reading of 0.00 and when phosphates are checked directly out of the RO/DI the readings are 0.00ppm. Are the new storage containers leaching phosphates into the water? <<If these are tests on 'water only' in the container (no salt mix introduced- ever), yes, your tests seem to indicate so>> If so, how do I prevent that or are there different containers that I should be using? <<You don't state what you bought...but I know many hobbyists who use the Rubbermaid® containers with no ill effect. Another option is to purchase vessels made purposely for holding 'potable' water...I use a couple Polyethylene drums purchased from USPlastics.com >> Thanks, Peter <<Regards, EricR>>

Re: Phosphate Leaching In Plastic Storage Vessel? -- 10/22/07 Thanks so much for the quick reply. <<Quite welcome>> I found a clear polyethylene drum that I will test under the same conditions. <<Excellent>> I believe the container I was using was indeed a Rubbermaid. Thanks, Peter <<Cheers, EricR>>

Phosphates in Pet Fish Food...  7/12/07 I have a 155 gal reef tank I have fed my fish only frozen mysis shrimp foods for years and about two months ago I bought a pellet food to feed with the frozen foods, <Good, variety is important with our critters diets.> the pellet foods say they have 0.8% phosphorus, can that make phosphate levels go up I have read that foods other than frozen can do so. <Many foods have phosphates in them which yet another reason not to overfeed. If you want to get down to it, rotting food is just another ammonia/nutrient source. It may also scare a few aquarists to know that most aquarium foods have some level of copper in them. Again the key here is not to overfeed, and with frozen foods do not put the defrosting water into the tank along with the food, rinse with fresh RO water several times.> My phosphate levels use to be zero now they read about 0.25, <Not overly alarming.> but I had not checked them for about four or five months until now. <If this a reef tank I would encourage at least bi-weekly testing.> Should I stop feeding my fish with pellets or do you think the phosphate levels just go up on there own, <All foods are a source of dissolve nutrients, so the question becomes how much should you be feeding? Only you can answer that question to suit your tank.> my tank has been set up for about five years I have a wet dry filter <That could be a source of your nutrient problems too.> with the skimmer built in for a tank up to four hundred gal. My tank is not over stocked with fish, my corals are doing great, but I have read that you want your phosphates to be zero. Thank you. <As cliché as this sounds, dilution is the solution to pollution! Keep up with he water changes and consider testing your source water for phosphates as well, if you're using an RODI or just RO filter even it may be time to replace the inserts. Good Luck! Adam J.> I hope I am wrong about my Lace Rock -- 06/29/07 Hey Guys, <Jim> I am hoping you will send me off in another direction, but any help at this point would be great. I have an algae issue (green hair / filament algae). I do weekly H20 changes with RO/DI water. I also "vacuum, brush and pull" the algae off the rocks 2x a week. <No fun...> I have great flow (20x) I also "brush off rocks to make sure...(desperate?) <Maybe> I also have tested my fresh and salt mix. All are 0 nitrate and 0 po4. My tank test 0 nitrate and 0 or very close on po4. I took my h20 into LFS to confirm and they did. I have a refug. and a res. with a protein skimmer. I have changed my lights (4 halide 150w 1400k). I am running with phospholock (sp? ferric hydroxide?) etc. I don't "feed" my corals etc. I only have 12 small fish in a 265 tank I am running a protein skimmer and clean it every other day. I may not have as many cleaner crew as a LFS would recommend, but they are breeding and seem to be doing fine. I have 2 tangs and a lawn mower blenny. I need to scrub my overflows daily because the algae is clogging them. I need to clean my sponge filter 2x a week because it is clogged with algae. I may need a shrink soon.... <Heeeeee! Maybe one with long arms who can help pull the algae!> I have a old live rock (that sat out for a year) from my old tank (50 or so lbs) with 60 that I got when I set this up and about 90 lbs of lace rock which sat in my old tank for 2-3 years as well (and then out for a year). <... I see> I had an algae problem in my old tank, but it was pieced together and I figured was due to poor set up / maint. <Mmm, maybe just one aspect...> Given all this...Could it have been the lace rock? <Yes> I put a piece in a bit of clean salt water and it seems to have raised the PO4, but test kits are not extremely accurate. I am out of other ideas. I hope I am wrong as I have the whole thing nicely strapped into a PVC frame that looks great and a bunch of SPS and LPS coral that is thriving when the algae keeps off of it. I really don't want to have to take it all apart and am not sure how I would even start doing it. But, I also can't spend 2 nights a week cleaning up the algae. <Yikes.... I'd be pulling, replacing> Any help would be great. The tank was "fine" for about the first 6 months but the last have been a real challenge. Oh and I add purple up <Oh! I'd abandon this product as well... More trouble than it's worth...> to try and get the good pink stuff thriving. Every thing looks healthy, SPS is spreading and growing, LPS looks good. Soft are spreading, xenia is the only thing that is not spreading (I am glad). Again thanks. <Mmm, well... there are even more countervailing strategies than the ones you have aptly applied here (refugium, skimming, chemical filtrants...), but I would remove the Lace rock, quit the Purple Up... and you should see, realize almost immediate improvement. Bob Fenner>

Re: I hope I am wrong about my Lace Rock 6/29/07 Thanks Bob. Does this process make sense? <Let's see...> Pull Lace Rock and stop purple up. See if issue goes away. If it does then Add new Live Rock to replace Lace Rock? <I wouldn't wait m'self> How do I make sure the LR is fully cured? <See WWM re: http://www.wetwebmedia.com/marinvind1.htm> I could add a piece at a time or keep it in a tub with a power head for a while. I know I have a good bio load in the tank but I am not sure what impact adding 50 - 70 lbs of live rock will have (except to my wallet..) <One approach> I have a water making station I could put some live rock in, but it is only a 35gal tub. <Big enough...> Thanks for your support. I look to your site often. <I as well... perhaps a bit too often and long! Cheers, BobF>

High Phosphate in RO water 8/12/05 Hello everyone, I'm a newbie to saltwater and I recently set up a 155 gallon reef tank.  In this time I've had trouble controlling my phosphate levels.  Here are my specs: 1.  155 gal tank 2.  Lightly stocked tank with 1 purple tang, 1 six line wrasse, 1 clown, 1 lawnmower blenny, 2 cleaner shrimps. 3.  2 mushrooms, 2 rocks of yellow polyps, 1 green star polyp. 4.  Two overflow boxes, aqua C ev-180 skimmer which produces lots of crap daily.  I use RO/DI water weekly and perform a 10 % water change every week. My RO system is from Coralife-pure-flo. 4.All water parameters are normal except the phosphate level which is a whopping 1 ppm with the Salifert test! I thought for the last three months that the levels were high because I was feeding too much but I wasn't.  Sometimes I would actually skip a day so my fish could graze on the little hair algae I have in the tank.  I then thought that my test kit was wrong, so I bought a new Salifert test kit.  Anyways, I decided to test my RO/DI water without salt straight from the tube and the phosphate levels measured 1ppm!  I then checked my TAP water from my faucet and it tested only 0.1 ppm.  I retested all my different waters and the results were the same.   I came to the conclusion that it seems like my unit is leaching out phosphate, is this possible?   The RO/DI unit is very new, I bought it 5 months ago and according to the instructions, the pre-filter needs to be changed in a months time and the membrane should last another 6 months.  So I still have time for change.  Any thoughts?  Nilesh <This is an easy one!  Activated carbon is made porous in the manufacturing process by exposing it to phosphoric acid.  If the carbon is not rinsed, it will leach phosphates in high concentration, much of which will pass through the RO membrane.  If you really want a shock, test the water coming directly out of the carbon block pre-filter!  The simplest option is to replace the pre-filters with good quality aquarium brand (something other than Coralife!).  Prefilters should be changed every six months to a year, but the membrane itself should last several years.  Best Regards.  AdamC.>

Phosphates in tap water   9/2/06 Hi again, I've been trying to get to the bottom of my phosphate problem and have narrowed it down to my tap water. What is weird is that when tested as fresh water it tests at about .03 on the Salifert Kit but when mixed with IO it tests only as traces of PO4 as saltwater. Does this make sense? Also, I do use a DI and results are pretty much the same. Do you think that using Polyfilter or phosphate sponge in one of the DI chambers would be useful? Thanks for all your help, past and present. Mordy Mordy Eisenberg <<Mordy:  If your RO/DI unit is working properly and you have a TDS meter, you TDS reading should be 000.  At that point, you shouldn't have phosphates.  If you have too much phosphates in your tank, growing Chaetomorpha algae in the sump, can help. Best of luck, Roy>>   High Phosphate Levels  10/23/06 <Hello Andy> Hi Ladies and Gents! I'm not sure how to classify this email really. It's a bit of a 'symptom' with a 'problem' with a question for a 'solution'... I think... I have a 30g tank with around 60lbs of Fiji Live Rock. It's about a year old. I have a small internal filter containing wool only, for mechanical filtration, a couple of MaxiJet powerheads and a thin (less and an inch) layer of aragonite and crushed coral substrate. <First question.  Are you changing the floss weekly?  If not, do so.> My levels are pretty good on the whole: Ammonia: 0, Nitrite: 0, Nitrate: 0, pH: 8.3, Salinity: 1.024. I do a 20% water change each week and use RO water which I have tested for Phosphate. I use Tropic Marin Pro Reef Salt. <OK> My livestock is about 30 Turbo Snails, about 20 - 25 Red Leg Dwarf Hermits, 4 small Feather Dusters and a pair of Clarkii Clownfish (female is around 3" and the male is around 1.5"). All the livestock seems active, happy, healthy and feeds well. <Don't believe you need 30 Turbo Snails in there, 10 would be more than enough.  Eventually, some of these may die due to starvation, causing more problems.> Recently I have had a problem with algae. My lovely rockwork has grown a thin film of very bright green algae (not the usual dark green I've seen before) and there are signs of algae on the glass and the substrate. I have a very high level of Phosphate in the tank (1ppm!) and I'm struggling to work out where it's come from (me, I know!) I have 96w of T5 fluorescent lighting which is one actinic and one 10000k bulb. These have an 11 hour photo period per day. <May want to cut that down to 8 hours and see if you have a reduction of algae growth.  If there is indirect lighting (outside light) hitting the tank, 10 hours isn't necessary with the animals you presently have.> I realize (through reading on here and books etc) that Phosphate is caused by - amongst other things - over-feeding and over-supplementing. I never supplemented much (the occasional 5 - 10 drops of Salifert All-in-One, Salifert Coral Food for the feather dusters and a couple of drops (literally) of Salifert Coral Calcium every week or so) but have now cut that out completely since about 3 weeks ago. I have always done my water changes religiously but am at a loss how my Phosphate got so high (I don't use carbon anywhere which I believe CAN leech Phosphate). <Cheaper brands of carbon are known for this.  You may want to try a Poly Filter in your system.  Just hanging it in the tank will help if you have no filter to use.> I have tried suspending a filter-sock with Tropic Marin Elimi-Phos in the tank, but that lowered my pH overnight (down to 7.9 the following day - even by midday it hadn't risen!). I then tried Salifert Phosphate Killer in the sock and even though it didn't lower my pH, it didn't lower the Phosphate either! So now my levels all look great again, apart from the Phosphate... <I like the RowaPhos product myself.  Might want to try this.> I am planning on doing a 75% water change this weekend - are there any potential problems with doing that? <I would do no more than 50%.> I guess my main question is, what do you think I can do to lower the Phosphate in my tank? I am very short of space, so a sump or refugium with Caulerpa is out of the question I'm afraid. <Just rubberbanding a hunk of Chaeto to a small piece of live rock in the tank will aid in phosphate removal.> My other question is: how much/often should I feed the Clarkiis? I'm worried about starving them, but am always careful not to 'overfeed'. The trouble is, they're so greedy, they'll just eat and eat. <Many people eat more than they need to.  A couple of small feeding twice a day is plenty.  The clowns should look full without bulging stomachs.  Keep in mind that fish do not have large stomachs.> I've heard the usual "as much as they'll take in 5 minutes" but that's so vague it doesn't really help me. I could probably get half a tub of food in there in that time and they'd scoff it all I expect. I feed them a mixture of Tetra Prima and the occasional bit of chopped Mysis! Given that Tetra Prima comes in granule-form, is there a rough amount of granules I should be feeding?  1ml of granules in a test-kit-measurer? That's actually quite a lot of granules! Random question I know, but I'm struggling here! <Feed sparingly twice daily.  If the fish seem to lose interest in the food, do not feed anymore.  I would put repetitive small amounts in the tank, if they consume all, add another small amount.  Not good to put all the food in at once with a couple of fish present.  I'm not saying to go buy more fish either, as your tank will become too small for the clowns in the near future as the clarkii's can attain a length of up to six inches.  When buying food, also look at the phosphate content of the food.  There are dry foods that contain quite a bit of phosphate in them.  You did not mention use of a protein skimmer.  Using one will definitely help your phosphate problem.  There are good hang-on models such as AquaC that are very efficient and trouble free.> Anyway - sorry to ramble on - any help/advice would be much appreciated! Many thanks! <You're welcome.  James (Salty Dog)> Andy Re: Too much MH lighting?   11/26/07 Dear Justin, <Hello again, George> Thanks for the fast response. <No problem, glad to help> A quick follow up to my lighting questions. <Ok> You got me thinking about phosphates! I've noticed that slight hair algae has started, and I'm using mechanical as well as maintenance measures to control. But I wonder if recent increase in feeding frozen marine mix and krill mashed up to a bubble coral and some brains, in addition to the zooplankton and rotifers may be overpowering. <It very well could be> So if you would be so kind, set me straight. How much invert feeding, for say 200 gal. should I be doing. I use a combo. of phyto-feast, and sometimes Roti-feast, and Arti-pods. This doesn't include the meaty bits I mentioned. The instructions say "1-2 teaspoons per 100 gallons. I think I may have been feeding too much because I was worried about   the bubble. <How often are you adding the liquid phyto/zooplankton mixture? I would recommend dosing the tank with this 2-3 times a week, 2-3 teaspoons total should be enough.> All the reading on the site indicates that unless the bubble coral eats daily, it will starve to death in a year. <Mmm, I don't believe this to be the case. 2-3 meaty feedings a week should be fine> And if so, is just a small portion for it sufficient. <Should be> Any insight you can provide on control of phosphates, with a focus on the feeding side of things would be great. Thanks again. George <Hope this info helps you out, George. Feel free to drop another line if you've got further questions! -JustinN> Re: Too much MH lighting?   11/26/07 Thanks, Justin. I will scale feeding down a bit along with lights and let you know what happens. Regards, George <Sounds good, George. Keep us posted, shoot a line back if you've got anymore questions. We're here to help. -JustinN> Found where my phosphates are coming from!!! hi bob <<Actually, it's JasonC today, how may I help?>> I have finally found where my phosphates are coming from. I have a 130 gallon reef tank lots of live rock ,good skimmer, a refugium with nice Caulerpa growing I have very few fish ,and sometimes don't feed for weeks. Why you ask? Because I had so much hair algae growing I let the fish graze on it. My phosphates were always around .25mg-l.I have a ro-di unit with new filters in. I had no idea where the phos. was coming from. Then a friend told me that his calcium reactor was giving off a large amount of phosphates from the dissolving aragonite. Does aragonite contain phosphates I asked myself. Then another friend told me that he used a product called Aragamilk and that he also saw phos. levels rise. My conclusion is that aragonite or at lease certain brands release phosphates. <<That is it... certain brands, but even so... most corals have some phosphate fixed within their skeletons so that later when they become gravel, that is released as trace amounts. Not typical that aragonite should release massive quantities of phosphates.>> So I had a problem because of an old trick my LFS told me .He said that when you fill a bucket or a tub with your ro water to pour a bag of aragonite in the bottom. The ro water comes out at a ph of 6.5 so it will dissolve the aragonite and voila!!! instant buffered water for water changes or toping off. <<Not sure I agree with this technique. The process described is similar to how a calcium reactor works except there's one thing missing - the CO2; no catalyst to dissolve the aragonite. And these typically recirculate for days. So... any alkalinity or buffers obtained from this method would be in small amounts.>> I have been using this method for a year but not anymore because I tested the water and it contains .2mg-l of $%?$ PHOSPHATES. I have a very intense lighting system with good ventilation in the hood, so I top off about 5 gallons a day so you can imagine the amount of phos I was adding in a week. I also cheeked if the ro water contained any phosphates and the test was nil. <<Ah...>> Have you heard of anybody doing this? <<Doing which? Having problems with leached phosphates - yes.>> did they have problems with phosphates? <<Not really.>> What do you think about it. <<Well, two things... I would start by just using straight RO/DI for top-off. If you want buffers in that water, add baking soda or Seachem Reef Builder. Then... add some macroalgae to the tank to compete with the hair algae.>> Would love your feedback. Richard <<Cheers, J -- >>

Leaking Phosphate...  3/25/03 Hi Phil<Hey Tony!> I wanted to let you know what I found out.<Let's have it!> I mixed up some salt water and tested it for phosphates it tested 0ppm then I broke some of the fingers off the corals and added them to the mix. 24 hours later I tested the water it read .6 if I bleach the corals and rinse very well of course do you think that will help or is there some kind of solution I can soak them in.<Well if it truly is the corals leaking then bleach may not solve the problem.  Bleach kills living things and can clean away the dead stuff, but it may just do more harm then good.  Head out to the LFS and grab yourself a small AquaClear filter.  Add a PolyFilter and you are in business.  Remember to change the filter often and it should help with the phosphate.> THANKS TONY<Hope this helps and good luck!! Phil>

Re: phosphate in my water I have had a recent algae bloom in my reef tank and have been searching for a solution.  I have been doing regular water changes, shortened my light cycle, not overfeeding, changed salt brands, etc. I know that one of the problems that may be adding to this is the amount of phosphate in the water.  I tested the RO water I use and it contains 1 ppm. Is this my problem? What is an acceptable level to have in my tank? <This phosphate is contributing to your algae blooms.  When you mix your new salt water consider adding a poly filter to it and let it sit a few days before you put it in the tank as this will remove the phosphates. Cody> Thanks for the help, I love the site! -Danny

Controlling Phosphates 7/23/03 Hi Antony, I need your opinion again. <always welcome my friend> I'm dosing Kalkwasser 2.5 gallons a day in my 250 gallons FOWLR tank and dosing Seachem Reef Calcium twice a week for coralline algae growth; in those days I stop dosing Kalk. Doing so my Ca level has gone from 450 mg up to 470 mg. How can I continue with Kalkwasser without raising Ca level too much? <you might ease off of the Sea Chem calcium for starters if the corallines have been sufficiently stimulated> Moreover I've another great problem: my phosphates level is 1.50mg/l. <yikes!> What can you tell me about ROWAPHOS or Seachem PHOSGUARD? Which is better? <Sea Chem has a very fine name brand... but the ROWAPHOS has shown tremendous results> Can they solve my phos problem? <both only treat the symptom (phosphate) and not the problem. I would not advise using much of either, but instead... identify where your phosphates are being imported from (source water, foods, etc) and screen it there first (better prefiltered FW, change of food, etc). One of the most common mistakes aquarists make which allows phosphate to accumulate is the thawing of frozen food in water and then dumping that water into the tank with the meaty food. Its a horrible habit and one that leads to phosphate accumulation and nuisance algae growth in general. Always decant the water away... or better yet, thaw frozen food in the refrigerator without water. The lack of water and the slow thaw will improve the nutritional value.> Thanks a lot Best regards, Lorenzo in Italy <with kind regards, Anthony>

-Fun with phosphates!- Hey guys, great site! I'm having a terrible time w/phosphates in one of my tanks.  Please help! Set up: 45 gal. corner tank w/ Penguin 600 power head for extra water flow; standard CaribSea aragonite sand, 3 in. base Filtration: Fluval 404 w/ standard foam filters, trays are packed w/ceramic biomedia 60 lbs. live rock Small Aqua Clear powerfilter for extra flow, mechanical filtration, oxygenation Inhabitants: 2 Brazilian Seahorses hippocampus reidi 2 emerald crabs, 3 peppermint shrimp, various hermits, sand sifting star, 2 green lettuce nudibranchs Parameters: pH-8.2; NH, NO3-nil; NO4-3ppm; CA-400ppm; Alkalinity-normal; SG-1.022; temp.-77 F PO4-3!!! <3 ppm or .3ppm?!> Water source: 5-stage RO, with add-on DI cartridge (this was the 1st thing I tested, there is no PO4 present in the water source) Background: I have had phosphate problems w/this tank before.  Problem was (I thought) the water source, hence the elaborate home system I purchased.  Got the PO4 levels down to .15 through very frequent water changes (10% 3 times a week) but now they're back up.  Need to find the source.  I'm feeding 1 Hikari Mysis cube per day, which seems appropriate.  Only source I can think of is dissolved organics. <Make sure you drain the juice in that shrimp. You may want to seek out Piscine Energetics Mysis as it is a much better quality shrimp.> Tank is not drilled, so my main question is should I invest in an over-the-tank protein skimmer? <I would recommend one.> p.s. I also have a 55 mini-reef that is not experiencing these problems. <I would wager that the packing water in the food is the source, unless your phosphate kit is wrong. In the meantime, run plenty of phosphate removing resin. Good luck! -Kevin> Thankfully

PO4 in Frozen food -An Informal Experiment >Hi Marina/Bob, >>Hello Jorell.  Marina today. >I hope you guys are well... >>Indeed, and yourself as well. >I do not know if you should publish this as it may be half$$@& job, but, I just read something on the FAQ's just now talking about draining frozen foods to lower the risk of contaminating the water.  About a couple of years ago, I had a algae bloom in my tank and was trying to source where the PO4 was coming from (I found out eventually it was the bio load, duuhhh, missed the obvious).  Any way I started testing various things including the frozen food I had been feeding my fish by diluting it in a fixed measure of water.  While I know every batch may be different I did this over a few months and averaged the results so I have some kind of guideline to go by. >>Interesting, and I like the idea. >I used to feed my fish a mix of: 1) Hikari - Mysid Shrimp 2) Hikari - Brine Shrimp 3) Sally's Spirulina enriched Brine Shrimp 4) A mixed frozen pack of Shrimp Mussel and squid. I will have to find my book where I have the (brand name of the Mixed food pack) and figures, but I found that, the Sally's Brine Shrimp had the highest Po4 content followed by the Hikari Mysid shrimp and surprisingly the Hikari - Brine Shrimp had very little PO4, all tests were done with a Salifert test kit. >>Yes, if you do find your results it would be interesting to see.  Thanks for the input!  Marina >Regards, Jorell

-Frozen food juice, does it do a body good?- While reading the daily FAQs this morning, I came across a response by Kevin to a phosphate question that suggests draining the juice from the Hikari Mysis shrimp the person is feeding the fish. <Well, if the incredibly handsome and intelligent Kevin said it, then you better believe it. ;) > I feed my fish different foods but one type is Aqua-Yums Mysis shrimp.  Is the draining of the juice an across the board technique or just for Hikari brand foods. <It's always recommended that you ditch the packing juice.> I had never considered draining the juice before and was also wondering if this techniques is supposed to be performed on all foods? <It would be a good idea, but I've been a non-juice drainer for years and have had no problem. That said, I don't use Hikari Mysis shrimp. I believe in that question, the aquarist couldn't figure out where the po4 was coming from, and he had apparently done everything right except that he fed an entire cube per day.> My water parameters have always been acceptable NH3 and NO2  0, NO3 10, ALK 10,  Ca 400, pH 8.2, temp 79-80, and salinity 1.023 - 1.024 but I don't test for phosphates or any of the other more specialized parameters as I just keep fish and a few crabs. <There's nothing toxic about phosphate to your critters, it's just an algae fuel and a problem for people with calcium depositing inverts. Have your LFS test your tank for phosphate, you could be on your way to an algae bloom and not even know it! -Kevin> Thanks, Ray

Mysterious Phosphate Reading Hi again, <Hi there! Scott F. with you today!>      Thanks a lot for answering my earlier question about fish stocking. This question has every professional in my area stumped and I've tried everything and don't have a clue. My phosphate levels are through the roof (3.0) with no apparent reason. I have only had the tank(60G) running for 17 days, I have one Chromis and some crushed coral but nothing else. I have tested the water supply and my salt mixture and the phosphate is below 0.1. I had been adding brine shrimp into the Chromis' diet but have stopped that for a few days now. My supplier suggested cleaning the filter(fluval404) in case something was blocked in there- it didn't help, I also cleaned my skimmer. If it is important I had a white film on the inside of my tank which I cleaned off the best I could (in one of your questions it said that it might have been caused by a ph buffer). If it matters I used powdered bacteria, Nitrivec and Amtrite down (ammonia/nitrite reduction stuff) to prepare the tank. All other tests are fine (ph is 8.1 and nitrite is undetectable) my supplier did all the other tests and said none was a problem. Also I tried a 10% water change last week and 35% this week with no results. This problem is no drama at the moment (I wasn't planning to put coral or anything in for quite a while) but my supplier recommends not to put live rock in until I solve this problem, which I was planning to do. Sorry if this question is a bit long but I thought it would be better to have the full story. Thanks heaps for your time - Ryan <Well, Ryan- phosphate is one of those things that comes from a variety of sources, among them foods, additives, and even source water. Relatively new systems have "immature" nutrient processing and export systems, so nitrates and phosphates commonly accumulate. This is a fairly high reading, though, so I'm sort of wondering if your source water contains measurable phosphate levels...Do check that out, and consider using RO/DI or other purified water sources. I also am curious if the powdered bacteria culture contained some culture medium or other food source which may be contributing to the reading. Still another thought is the substrate material that you are using...Some grades of crushed coral may have impurities in them- a long shot, but something to think about. I'd try to eliminate some of these as sources, and then look at means to control phosphates, such as continuous use of chemical filtration media, like activated carbon and/or PolyFilter, or even some of the dedicated phosphate removing media, like PhosBan. PhosGuard, and Rowaphos. Look beyond the obvious, and do consider one of the aforementioned media as an adjunct to your control efforts! Good luck! Regards, Scott F.>

Phosphate in Nori and Kombu? No worries 2/16/04 Hi, I have just acquired a Scopas Tang, for which I have bought some Nori, and  kombu. My worry is that in feeding these, I will probably be introducing  phosphate into the tank, am I right that these will contain phosphate? <no worries at all... nominal indeed. The real problem with phosphate laced foods is from terrestrial farmed/grown produce like lettuce/spinach, etc which is grown with heavy doses of phosphate and nitrate based fertilizers> Is there something I can do to reduce the phosphate content of these foods before feeding? <focus instead on utilizing or exporting it in the aquarium. Other sources of phosphate will enter and need addressed anyways. Use of calcium hydroxide is great for this (precips phosphate)> Also, can the kombu be boiled to soften it without destroying nutrients it contains? <like our/any foods... it will destroy some/many nutrients. If you must, briefly blanch it instead> Also, I bought this stuff at the Asian market, how can I know it has no added preservatives or other chemicals? <honest list of ingredients is the best I/we can hope for> Finally, do you have any other suggestions for a balanced diet for a Scopus Tang? At present, along with the Nori and kombu, it gets the mussel and clam fed to the other fish. <having a variety of 6-10 foods of random origin and processing will likely be fine (FD, Frozen, pellet, fresh). Focus as you have done on a heavy green component... and do consider growing some Gracilaria (AKA "Tang Heaven" from IPSF.com) in a refugium. Anthony>

Phosphate, Calcium & Alkalinity Hello Guys: Could you please try and help me with a problem that developed suddenly in my aquarium?  I have read the FAQs and want to make sure I am pursuing the proper course of action.  Aquarium is one year old.  Tank is 240 gallons with 200 lbs LR.  Sump is 15 gallons with Euro-Reef  CS8-3 skimmer which flows into 100 gallon non-lighted refugium with DSB of 8 inches aragonite.  I follow good husbandry schedule with 10% weekly water changes, activated carbon run in sump continuously and changed monthly.<Sounds like a nice system.> I use Salifert test kits (test once per week) yielding the following range of results: NH4 0.25 ppm, NO2 Undetectable, NO3 2.5 - 5.0 ppm, Ca 380 - 420, Alk 3.0 - 4.0 meq/L and PO4 Undetectable.  Electronic pH meter ranges 8.17 -8.28 and electronic salinity ranges 1.0240 -1.0250.  A 4 stage RO unit with Instant Ocean salt mix is used for make up water.  B-Ionic 2 part balanced additive dispensed over 8 hour period daily and evaporation top-off via reef filler pump at 1.5 gallons daily with RO water.  I am feeding fish once daily and decanted the frozen food.  A "live" commercial brand phytoplankton was administered 4 times a week.  Everything was running fine. <I am very suspect of an ammonia reading above zero.  I would compare this with another kit.  Otherwise, it sounds like all is well.> I tried a different "live" commercial brand of phytoplankton for one week  and my phosphate increased to 3.0 ppm.  My alkalinity increased to 5.71 meq/L and calcium 450 ppm.  The pH increased to 8.48.  What I am thinking is that the high phosphate level has inhibited the calcification process thus causing the excess amount of calcium and alkalinity in the water column which in turn is driving up the pH.  What do you think? <Sounds logical, but I wouldn't expect the change to be so dramatic or fast.> Could the commercial phytoplankton have caused such a dramatic increase in phosphate in such a short time period? <Yes.  One brand in particular takes care to was the phyto free of fertilizers.  Other brands may not.> Does the calcification process shut down so quickly in response to the elevated phosphate? <This is the part I am suspect of.  Phosphate will slow calcification, and my do so quickly, but I am suspect of the rapid rise in Ca and Alk.> I have done 10% water changes every third day for one week but the phosphate level still remains at 3.0 ppm.  I stopped the B-Ionic dosing and the calcium and alkalinity are slowly decreasing.  The RO water and Instant Ocean mixed with RO water both have undetectable phosphate levels.  Why do think the phosphate level in the tank remains so high?  Thank you very much for your help.  I am worried about my live stock.  Joe <I would continue this regime until the phosphate decreases, or consider a commercial phosphate remover.  Seek out Iron based products (red color) like RowaPhos, Phosban or Salifert and avoid alumina (white color) based products.  Since the introduction of the phosphate seems to be a "one shot" event and not a chronic problem, you should be able to get it under control easily.  Good luck.  AdamC.>

Phosphate and phytoplankton Hello Adam C: << Adam C is out right now, so I'm jumping in. >> Thank you for the help.  I have added both Rowa-Phos and a Poly Filter to the sump.  In addition, I will continue to do the 10% water changes every third day until the phosphates become undetectable again and then I will remove the Rowa-Phos and Poly Filter.  In your response, you stated one "live" phytoplankton brand has good quality control to remove phosphates and nitrates, is this DTs phytoplankton? << I don't know whom he was referring to, but I think Mountain Corals and Phycopure are both great as well as DTs. >> DTs was the brand I was using with no elevation in phosphates.  The brand which caused my phosphates to become elevated was Instant Algae manufactured by Reed Mariculture in California. Please let me know what you think. << I also like Reed Mariculture and Florida Aqua Farms and I love Brine Shrimp Direct's Tahitian Blend Algae. >>  Thanks again for your insight. Joe <<  Blundell  >>

Kent carbon, Phosphates and algae Dear Sir's, I have had an algae problem since setting up my reef tank 8 months ago, mainly hair algae (the usual I know).  I think they call it hair algae because when you get plagued with it you pull your hair out!<HA!!> The tank is 250uk gallons and has around 120-130kg of live rock 3x 250watt 14k metal halide lamps around 6 months old. I use Rowaphos continually. The phosphate measures 0 with the new high accuracy Deltec test kit. Nitrate also measures 0. I have used Kent reef carbon since setting up my aquarium.  I use instant ocean salt and have an AquaMedic 1000 calcium reactor set to 6.7ph and about 2 drips per second effluent. Lots of water flow with 2 Tunze 6100's, all top off through Kalkwasser stirrer with RO. Water changes, about 7% per week. Now, my question, sorry to rattle on....<No Problem.> Just recently I decided to test the carbon for phosphates against the AquaMedic brand. I put a few pellets of each make, 1 week old carbon into some RO water. The Kent carbon went off the scale on the Deltec test kit to around 0.6ppm while the AquaMedic tested around 0.2. I am concerned that this is fuelling my algae bloom and I am not reading phosphate in the tank as the algae is utilizing it. What do you think?<It absolutely could be the situation.> Does this sound like it could be the problem?<Yep!!! Your testing methods was a good step to take.> Any information will be of a great help....I looked under the different carbon topics but couldn't find anything of this nature. Please let me know if you would like anymore information. Kind regards, Lee <Lee, There are carbons that contain phosphate in their molecular structure.  Is there any reason why you are running carbon in your reef tank.  If you have a sufficient protein skimmer then you won't need to use carbon.  I would also recommend testing for silicates.  They can cause algae blooms also.  Remove the carbon and physically remove the algae and see what happens.  Good Luck MikeB.> Phosphate Hi guys, first time writing, great site.<Thank you> I have a reef/fish aquarium that is about 6 months old.  Things have been going pretty well, but I have lost a couple of corals and the occasional fish.  The system is 55 gallons, 100 lbs live rock, eight small fish (2 gobies, 2 Chromis, 2 clowns, lawn mower blenny, six line wrasse) 4 different kinds of shrimp, two anemones.  Corals include a bubble, frog spawn (two kinds), a sun coral 'bunch', couple of small Acroporas, a medium trumpet, a small gorgonian, and the usual assortment of hermit crabs and snails (~25 each).  As I mentioned, I have lost a couple of corals, an elegance (wish I had read your website first) parts of the frog spawn and a banded shrimp. The trumpet isn't looking good either.  Fish seem to be doing fine. I feed the tank blended clams, mussels, shrimp and fish (all fresh, then frozen, about a ½ teaspoon couple of times a day).<Way too much food.>  I also add Cyclop-eeze <Are you referring to "Cyclop-eeze? If you are, this is a very good food source by itself for corals.> about every other day. <What does your lighting consist of, Nick?  This may be part of the problem in losing corals.>  My test results have generally been within the parameters I have been reading about - no ammonia or nitrate spikes, no algae problems.  I did a test last week after a hiatus of about 3 weeks and found my phosphorous at 6 ppm!  I use well water that tests (Reef Lab dropper kit) at about 0.2 ppm  phosphate.  Could the phosphates in the well water be building up?  Any other ideas, do I need to go to RO water? <I'm assuming you also have an algae bloom.  With phosphate levels that high out of the tap, it can certainly lead to this.  Do you do a 10% water change weekly?  Yes, I do think you should go to RO water or a de-ionized water.  James (Salty Dog)> <<Groan... the question James...>>

Fighting Phosphates and Keeping Water Quality High! Hi Scott, <Hello again!> Thanks for the response.  On the phosphate test kit reading, I said "maybe slightly" because the color difference between the "no reading" and the "first reading" is extremely hard to tell apart. <I understand...Many of the kits we use can be a bit hard to read the results on!> Sorry, I'm not at home, so I don't have the brand of kit in front of me or what the "first reading" measurement is.  If only a slight amount of phosphate can make a difference, I probably need to get another kit.  Any good recommendations? <For real accuracy, you could get a Merck phosphate test kit, but they are rather pricey. The Salifert, LaMotte, and Hach lines are good, too.> I also didn't mention that I cut the feedings back to every 2 days out of 3. <Well, don't starve your fish, but certainly do feed carefully when you do. Your continued careful husbandry will get you through this. I like to be habitual in maintenance, doing the same routine regularly, adjusting if required, but otherwise being relentless. Consistency is a good thing. Develop and maintain those good habits!> On the carbon (charcoal is a little old school), I've used Black Diamond and Kent in the last 2 months.  I've used ChemiPure in the past. Any recommendations for carbon?  I certainly don't want any that will leach phosphates. <Both the brands that you mention are fine, IMO. I alternate between Seachem Matrix Carbon and Rowa Carbon, myself, and get very good results.> I'm also using Kent salt.  I think I remember some folks questioning it's quality.  Any personal thoughts there too? Thanks, John <I like many Kent products, but I have not used their salt. I've used Tropic Marin for many years, and have just stuck with it. You might want to check with your fellow hobbyists to see what kind of results they are getting with this mix. Whatever brand you settle on, I'd stay with it if you get good results. Consistency is so important, IMO!> Leaching of Phosphates Good evening crew.  <Good afternoon>  I wanted to run a theory by you guys. I have a green hair algae issue in my 29gal marine tank. I've discovered the problem to be excess phosphate. Phosphate levels are around .6ppm. I tested for nitrates, but they come up around 0ppm. I use DI water only in my tank and phosphate testing of the water of course comes up negative.  I do however have a single piece of reddish colored lava rock in my tank and browsing through the FAQ sections leads me to believe this could be the culprit (the algae grows most prolific on this rock.... more so than my live rock) I will remove the rock. Do you think the lava rock has been leaching phosphates because I can't think of any other way they are getting into my system? Thanks a million, you guys are fantastic.  <Eric, phosphates can also be introduced by certain foods, and most activated carbons will leach phosphates, especially the cheaper brands. If you are using carbon, I would switch to a product like Chemi-Pure. James (Salty Dog)><<Uh, the question James... Yes, this rock, and most

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