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FAQs about Marine Substrates 9

Related Articles: Marine System Substrates (Gravels, Sands) by Bob Fenner, Marine Substrate Options by Sara Mavinkurve, Deep Sand Beds, Live Sand, Biofiltration, Denitrification, Live Sand, Live RockBiominerals in Seawater, Understanding Calcium & Alkalinity

Related FAQs: Marine Substrates 1, Marine Substrates 2Marine Substrates 3, Marine Substrates 4, Marine Substrates 5, Marine Substrates 7, Marine Substrates 8, Marine Substrates 8, Rationale, Selection, Reef  Substrates, By Type: Aragonite/s, Coral Sands, Silicates, Dolomites/TapAShell, Southdown & Such, Collecting Your Own, & Physical Make-up, Size/Grade, Location, Depth, Marine Substrate Cleaning 1, Marine Substrate Cleaning 2, Moving/Replacing/Adding To, Marine Substrate Moving/Replacing/Adding To 2, Substrate Anomalies/Trouble-Fixing,

Most all marine "gravel" has some mollusk contribution. Lloyd's Horse Conch et al. pic, including flash...

Shallow sand bed questions      3/7/17
Dear WWM Crew,
<Hey Rick>
I have been reading all of the information on WWM articles and FAQs related to shallow sandbeds, and reviewing my copy of Conscientious Marine Aquarist, but am a little confused in a couple of areas. My experience has all been with DSBs in larger tanks, so going with a SSB is a bit new to me.
<There are reasons, and proponent of both; and none! Shallow ones look better than naught, but are easier to keep clean; do provide some additional alkalinity and alkaline earth materials, substrate for habitat/organisms...>

Here's the description of a new 60 gallon cube I am setting up for my wife. It will have a good amount of water movement with an Eshopps RS-100 sump, Reef Octopus 110INT skimmer, Sicce 4.0 return pump running at about 650 gph at the tank's head height, two Jebo PP4 programmable wavemakers (132-1850 gph) , and an MJ1200 pump feeding a mixed carbon/gfo reactor.
There'll also be an ATO added. She wants a shallow sandbed so planning 3/4 inches of CaribSea Special Reef Sand. The lighting is an Aqua Illumination Hydra 26HD mounted 8 inches AWL. Salt mix will be Instant Ocean Reef Crystals. Water changes and will be 10% weekly, including vacuuming half of the sandbed each week.
<A good regimen>
Livestock will be more towards corals with a medium population. Estimated total water volume after sand and rock is about 70-74 gallons.
My first question is on the amount of live rock recommended when running a shallow sandbed. I have always used the "1 to 1.5 pound-per gallon"' rule, but reading a lot and hearing at LFS that the current recommendations are for less rock, using around 3/4 to 2/3 pounds per gallon rule.
<Am more of a fan of this latter; and the use of less-dense (S. Pacific) rock. Bommies not walls is a motto>
Since my understanding is live rock has limited ability to reduce nitrates, what, if any, impact does the sandbed depth have on the amount of live rock to use?
<Mmmm; both aid in denitrification and interstitial fauna (food et al. organisms) production... Depending on composition and surface area both add the aforementioned chemical help>
Do you feel 40-45 pounds of rock is enough for his tank or is more recommended. I am using mostly Fiji live rock.
<This amount is fine. Try it and see; you can add more later if you want>
My other question is on the cleaner crew to add in a few weeks. I'm thinking of going with a couple of Sally Lightfoot crabs, a mix of smaller snails (mostly Nassarius, Ceriths and bumble bee) but beyond that unsure what to add.,
<Meh; am not a fan of crabs really; and just a few snails...>
My wife's heart is set on adding a goby and Peppermint or cleaner shrimps. But with a SSB I am concerned about starvation for them.
Any recommendation on mix and numbers for a cleaner crew?
<Naught more than we have archived on WWM; really>
Thank you for all of your help and all you do for our hobby!
Rick Morris
Dacula, GA.
<A pleasure to share; aid your efforts. Bob Fenner>

Adding gravel to saltwater aquarium, using WWM       11/18/14
I have a 55 gal tank with a couple of fish, LR, and a few soft corals.
The tank has been established for 8 or so years and I have never added nor disturbed the gravel (other than lightly vacuuming the top 1/2 inch or so during water changes). Over time, the gravel bed has been depleted due to vacuuming loss.
<Plus the acidic/reductive events that go on there biologically>

What is your advice on adding gravel to raise the bed depth? May I just add new, rinsed gravel to the top of the bed?
<Mmm; yes... perhaps more to this. Read here: http://wetwebmedia.com/SubstReplF3.htm
and the linked files above. Bob Fenner>

Nitrates Control & a Tank Upgrade. Mar. Substrates f' as well <All covered on WWM>      5/5/14
Hi -
I am about to transfer the contents of my established 110 gallon SPS reef tank to a 225 gal reef tank that I am currently cycling with about 125 lbs of live rock. I will then move the approx 120 lbs of live rock & SPS from the 110 to the new 225. Recently I developed a nitrate problem in my 110 measuring about 20 ppm.
<Of and by itself; this isn't "much" of a problem. Put another way; I would not panic... To be expected in a new sys. w/ this much new LR>
I do 10-15% water changes every week. My Phosphates & Ammonia levels are at zero. I have added additional liverock to my Refugium which is housed in a 30 gal sump. I have reduced my feeding schedule even though I have Anthias that require twice a day feedings & made sure my skimmer is running effectively. Since then my Nitrate level has come down to 10 ppm.
While doing some research on your site, I have come across some conflicting information regarding the level of substrate in the display Tank vs. substrate level in my Refugiums. Most of what I read indicates a deep sand bed in the Refugium of 3-4 inches.
<This or deeper; yes... fine sand better than coarser>
However, I am also reading information that seem to indicate that a deeper sand bed in the Refugium may attribute to higher Nitrates. I am I supposed be syphoning or stirring the substrate in the Refugium?
<Mmm; I am a fan of occasionally siphoning, stirring part (no more than half)>
I have also been told it would not be a good idea to transfer the substrate in the my display 110 tank to my new 225 display tank.
<.... this is gone over and over on WWM; but there is a palpable argument for and against here... IF the substrate is very old, not much of it will be soluble... hence; not as much use... BUT if it isn't "too olde"; it bears rinsing and re-use>
I have also been told by my LFS to use as little new substrate in my new tank as possible
<Indeed; many systems do mighty well w/o any... i.e. bare bottomed>
They are indicating to put the liverock in first and then use just enough substrate to cover the bottom of the tank to avoid having a future nitrate problem. What is recommended level of substrate in the display tank if using a refugium in the sump?
<... Read here: http://wetwebmedia.com/refugdsbfaqs.htm
I am also confused about
what is best for nitrate control, larger coarse sand or finer sand.<... finer; definitely>
Any help you could provide would greatly be appreciated.
<A real point here: STRIVE to understand the underlying rationale/science for the input you're considering... Your understanding en toto will increase logarithmically. Bob Fenner>

Substrate use, SW   6/19/2013
Hi Bob,
How are You?  I hope You all right.
I'm sorry to bother you.
<Not a bother>
I would like to know your opinions on the sand in an aquarium with fish.
is better to keep the fish in the tanks without sand? I  mean bacteria (Cryptocaryon, etc.)
<Not bacteria; Crypt is a Protozoan>
 that may be in the sand.
<Most display systems are better w/ substrate; read here: http://www.wetwebmedia.com/SWSubstYesNoF.htm
If better without the sand, how to keep gobies?
<See goby-oid systems on WWM>
Thank You very much for any advice.
Best Regards
<You'd, you'll save time by learning to use the search tool, indices on WWM. Bob Fenner>

Marine aquarium substrates (WAS re: starting a brackish tank) -- RMF, feel free to edit/correct     10/20/12
Hi Neale,
When I last emailed you, we discussed adding sand to the freshwater substrate I purchased in order to prepare my tank for brackish water fish. 
Now I've decided to do a saltwater tank instead.
<Don't forget you can often do both! Many of the best oddball brackish species -- such as Green Spotted Puffers -- do extremely well in marine fish-only systems, and as it happens, GSPs get along better with punchy damsels like Dominos and Humbugs than almost anything else! Likewise Scats and Monos will thrive in marine systems, and Colombian Shark Cats make outstanding "Sharks" for big fish communities.>
Since the freshwater substrate I have is supposed to be safe for saltwater, can I still just add 50% sand to keep the tank buffered enough for a saltwater tank.
<Yes, you can. But if this is going to be a reef tank, do remember that changing things after it's set up will be expensive and difficult. So you may want to build a reef tank "by the numbers" sticking entirely with reef-grade materials like live sand and live rock that will ensure optimal conditions. FOWLR systems are easier to take apart if needs be, and plain vanilla marine fish communities are no more difficult to rebuild than freshwater systems. So with these tanks you may feel it's safe enough to use existing sand and rocks because you can always change things if you find the pH isn't staying where it needs to. Fundamentally though, there's no reason you can't use even gravel in a marine aquarium -- and I have done so with coldwater marines! It's just that marine sand and crushed corals offers better pH buffering.>
Also if I have 160 pounds of freshwater substrate, how much sand would be enough?
<I'm not a real expert at this side of things when it comes to marines.
There are lots of useful articles though. Maybe start here:
The main thing is to understand that in most cases you only need enough to cover the glass and add some landscaping, but if you go the deep sand bed route that's a whole other set of criteria, and if you have an undergravel filter, then again, that's another set of criteria you need to satisfy. So it's much like a freshwater aquarium: do you want enough sand to hide the glass, or to provide chemical buffering, or for biological filtration, or for the needs of certain living organisms (burrowing starfish for example, or Jawfish). Decide what you want, do your reading, then act accordingly.
Cheers, Neale.>

Substrate and Ozone Questions 9/30/11
Greetings, Crew.
<Hello Dustin>
I'll keep it short and sweet today.
In setting up my new tank, I'm trying to decide on a good substrate to use. I've been advised against oolitic, as it blows around too much and gets too compacted too easily. However, I do have burrowing livestock (watchman goby, various snails), so I didn't think crushed coral was an option (at least, not at the grades I've seen). I want about a 3" sand bed in the display for aesthetics and my critters, with NNR being taken care of by the mud in my refugium, and other reduction being handled by various equipment/media. Any recommendations? Is it safe/wise to do a layer of crushed coral on top of aragonite?
<I would just use fine aragonite sand. Your burrowing animals will appreciate it.>
Also, I've been reading up on Ozone lately, including a few articles on WWM. My system is only a 40 gallon breeder with a 29 gallon sump, but having a higher ORP seems to be beneficial all around (provided it's not too high). I'm planning on borrowing a meter from my LFS to check out what mine is, and I'm definitely interested in the benefits of Ozone (clarity, smell, overall health of livestock), but it seems marketed mainly to aquarists with substantially larger systems. Is there an alternative method of increasing my ORP without buying an overpowered, expensive unit designed for much larger systems?
<Ozone can be used in smaller systems as most Ozonizers have a variable output control to adjust the amount of ozone being produced. It's best to use a controller with these units to prevent high ORP levels as well as maintain the selected level. There are alternative means to  increase water quality and can be viewed here.
<Ditto. James (Salty Dog)>

Sand Beds, 3/2/10
You know, this hobby would be much easier if I was actually intelligent.
<Join the club.>
Nevertheless it is a blessing to have WetWebMedia as a resource. I have a couple questions on DSB's. With the help of WetWebMedia, I'm constructing a new 180g with a 50g sump. About 20g within the sump will be used as a refugium to help improve water quality. I'm planning on using a combination of LR, macroalgae and LS.
I believe I understand you preference/recommendations on macroalgae and LR, but I still confused about the LS.
From the 10,000 hr's I have spent reading about LS on your site, I find many mixed reviews. Since I seem to be unable to discern the answers to my questions, would you mind assisting?
<Fire away.>
Given the refugium size (13"x24"x17"tall) within my sump, and purpose, what would you suggest;
1. What would be your recommended size & type of LS?
<I personally would not use live sand, fine aragonite sand will become live with time and seeding from the live rock, especially true if you are going to go with a deep sand bed for nitrate reduction where you would just end up burying most of the life you paid for anyway.>
2. Should I use a Plenum (basic underground filter without tubes as a platform for LR)?
<I wouldn't, will slow flow too much through the sand and trap detritus.>
3. Should I support the LR with a foundation of dead rock, to keep sand from being under the LR?
<If you are going with a shallow bed here (< 1 inch) then just place the rock directly on the glass (carefully) and fill around it with sand. If you are going with a deep sand bed (4+ inches) then I would go one of two ways, either just place your rock directly on the sand (which has some downsides where dead spots can form, but is easy and the way I personally did it) or create a framework of PVC pipe to rest the rock on to allow for better flow of water through the sand. The second way is better and if I were to redo my tank what I would do, but I'm lazy, what can I say.>
3. What would be your preferred LS depth for my application?
<Less than 1 inch if you are not looking for nitrate reduction, more than 4 inches if you are. The middle ground will just cause you headaches with no benefit.>
4. Because of the required "stirring maintenance" and potential for a "nutrient sink" developing, would I be better off just eliminating the sand and just use the LR and Macroalgae?
<You could, depends on what you are trying to accomplish.>
Thanks for your help and wonderful website.
Les Currey

Sand beds in marine aquariums   7/11/09
Hello crew,
I have been looking over your FAQ's about DSB's and such and I was wondering your thoughts on something for a possible 600 gallon reef tank I want to set up in the future (about 2 years from now). This tank would have a nearby dedicated room housing the sump, skimmer, chiller, etc, so I wouldn't skimp out on equipment due to lack of space. I would have 650 plus pounds of live rock.
I know there is a lot of internet talk of the bare bottom tanks. But I have heard that SPS reef tanks tend to do especially well with such a setup. Do any of you have experience with this type of setup with SPS corals?
I don't especially like the looks of such a tank, but I didn't know if it was better for the SPS corals to do it this way as long as you provide excess flow and filtration, etc.
<There are pro and con arguments for such... I am much more in favour of using substrates myself... even in intense culture operations>
Regarding DSB tanks: for a tank like I am talking about setting up above, would it be possible to use a .5-1mm substrate/sand at about 2-3 inch depth for the main tank and use a very fine .125-.25mm sand at 4-6 inch depth in the sump?
Would this give me the benefit of a DSB without actually having the DSB in the main tank?
<Very likely so>
I understand surface area comes into play, so if you have the sump made large enough would that work?
And if you use a DSB (either in main tank or in sump/refugium), should you EVER try to clean or stir the bed (i.e. with a siphon hose during cleaning)?
<IMO yes>
Or should you just clean the top inch or so or what? And would a tank using a DSB ever need to be "broken down" after say 10+ years due to detritus buildup even if water parameters are continually in check and normal and the livestock is doing well?
<Likely this would be a practical matter... with adding more soluble material every half to full year or so... as you'll find the substrate dissolving...>
I mean, if the tank is doing well in all aspects, is there ever a need to take everything down and clean it all after 10-15 years or so?
<Mmm, not necessarily taking down totally... but as stated, this may be the more practical route to go; versus siphoning out old/less soluble remnants of the "old" substrate, adding, replacing with new>
I have heard of people recommending "taking a tank down" and redoing it after so many years, but not necessarily when using a DSB setup (and in these cases the tank is usually experiencing some problems with water parameters or livestock not at optimal appearance). At the same time, most people use a siphon to go into the sand bed and clean it when doing a water change; but it that a proper thing to do with a DSB or do you literally just "leave it alone"?
<Please read here: http://wetwebmedia.com/substrepl.htm
and the linked files above. Bob Fenner>

Substrate, adding too 11/12/08 To the masters <Where?> Matt here again, I was wondering what your opinion would be on adding dry substrate to an existing tank that has been up an running for five years. With all the cleaning of the substrate over the years I need to add some more to one of my tanks. The substrate in the existing tank is Aragamax Oolite sand. The bed started out about 3-4" thick and now is about 2-3" thick. I was thanking of using a brand by CaribSea called Aragamax Grand Bahama sand. It has a grain size between 0.2-1.2 mm. <Sounds fine.> My plan was to add a couple of cups each week during my normal cleaning and water change out. I would pre soak and clean the substrate before adding to the tank. Once in the tank my plan was to mix the two. Do you agree that this plan would be ok? <I would not really worry about mixing the two, as long as you just add a little bit at a time to the top it should be fine.> I really do not want to have a big die off and cause the system to cycle. Please advise oh great one's. Matt <As long as you do not bury the existing sandbed under the new sand most all the life should migrate to the new top.> <Chris>

Bare bottom tank -10/28/08 I have a 55 gallon well established reef tank currently with a bare bottom. What are your thoughts on keeping various mushrooms, xenia, Zoanthids and other soft corals as cover for the bottom of the glass tank. <I've seen others doing this. I've never heard of any major problems with it (if you can make it happen for you). Some people seem to have a little trouble getting the coral to grow the way they want it too, but there's no theoretical problem with the idea that I can see.> I have a decent size cleanup crew. I plan to add a refugium below the tank in the stand, and will light it 24 hrs a day. Will this constant light from below be a problem for the bottom dwelling corals? <Huh... I doubt it. If you notice it confusing your corals, you could always just tap some black construction paper under the tank (or cover it with duct tap maybe)... or use starboard inside the tank, on the bottom.> Thank you Corey <De nada, Sara M.>

Substrate and plenum 07/28/2008 Hello Crew, <John> Hope you are all having good summer so far. I am writing today to ask for some advice. I will upgrading my SW tank from a 37 gallon to a 55 gallon. I am struggling to decide on what to do for my substrate. My current 37 Gallon has about 2 inches of aragonite sand, which has been somewhat of nuisance over the last 2 years. I am constantly removing a layer of detritus and replacing sand. <Ah, yes... I'd switch either to an inch or less, or four or more inches of fine/r coral sand... Please read here re: http://wetwebmedia.com/marine/setup/index.htm the seventh tray down> The 37 gallon has about 50lbs of Live Rock, several mushrooms, polyps, 2Frogspawn and 3 fish, (OCA, 6 Line wrasse and a reef Chromis). I am thinking I want to bring the 55 up with an entirely new substrate rather than re-using the old stuff in the 37 gallon. <Yes, I would as well> Fortunately, I will be able to run the two tanks concurrently for a few months. <Good plan> I plan to slowly migrate my Live Rock and corals over that time. I plan to seed the bio filter in the new tank with media from the filters in the 37, and finally move all filters over to the new system. For filtration, I have a Tom's Rapids Pro PS4, without the bio balls, and a Fluval 204, which I run at about 50gph pr hour to feed my Coralife turbo twist 3x UV unit. The PS4 has Seachem Matrix, Purigen, and a phosphate pad in it's chambers. The Fluval has Seachem De-nitrate and a bag of Purigen. <Mmm, I would not run all this chemical filtrant... I WOULD look into other means of better accomplishing their desired effect... a DSB, macroalgae culture... perhaps all relegated to a refugium> I also have a Hydor Koralia water pump. I will run HOB power filter and couple MaxiJets temporarily on the 55 Gallon until migration is complete. The 55 will eventually have the same filter system from the 37 gallon with the addition of another Koralia water pump. For substrate, I was planning a plenum in the main tank, as I do not have and will not have sump. <Up to you. I would> The 55 gallon was given to me with a multi plate UGF, which I was going to use for the plenum. The plan was to cover the plates with an inch of crushed coral, then a nylon screen, and 1.5 to 2 inches of fine sand over that. <... see... oh, I see this below> I have been reading over the FAQs in the substrate and plenum section but I am still not sure if this solution is a good idea. I would appreciate your thought on this plan. As always, thank you for your wonderful contribution to our hobby, Regards, John <Welcome. Again, it t'were me/mine, I'd either run the fine coral sand DSB in this main tank/55 (no aesthetic drawback due to its height), or better, add a live sump/refugium, and save the big money from the chemical filtrant biz. Bob Fenner>

Reef Experiments -- 05/26/08 Two quick questions for you guys. <<Shoot>> Anyone ever experimented with adding crushed egg shells to a reef tank for calcium and makeup sand? <<Hmm, not that I am aware'¦nor am I sure just how 'soluble' or 'suitable' this medium would be'¦ Interesting idea though'¦ But, it seems much easier to just use a readily obtainable Aragonite sand, to me>> If not I'll let you know how it goes. <<Okay'¦please do>> It took a while to peel off the thin membrane from the egg <<I'll bet>> but it's a nice bright white "sand" in the tank. Also, has anyone ever used lava rock for live rock? <<Have heard such, yes. But this is not generally recommended due to the possibility of introducing pollutants (unwanted minerals/heavy metals) possibly present within the Lava Rock>> I was wondering if regular landscaping lava rock, being light and porous, would host the bacteria as live rock does? <<Sure it would'¦but it won't provide any buffering capacity at all'¦and you run the risk of poisoning your tank>> Thanks. <<Happy to share. Eric Russell>>

Sand Clumping 05/19/08 Hi guys, <Jason> Got some serious sand clumping issues!!! But first, some tank specs: Tank = 5ft x 2.5 x 2.5 Sand bed = Jaubert System, setup from bottom to top as such ?. ¼ inch PVC pipes -> egg cart -> fine mash -> 2 inches of 3-5 mm grain sand -> egg cart-> fine mash -> another 2 inches of 3-5 mm grain sand. Added a remote sand bed = Big bin with sugar fine sand to a height of about 3 foot. Water flow = High Corals = 80% SPS dKH = 10ppm Ca = 400ppm Mg = 1500ppm <A bit high proportionately> PO4 = 0 NO2 = 0 NO3 = 0 Skimmer = Hydor 2000 (rated 2 x tank volume) Fluidized Reactor with PO4 removing media <This may be problematical here> Activated Carbon put in 1 week per month <Good technique, interval> Tank setup = 18 months I think I know how it happened ... when I first started my tank, I had some KH, Ca, Mg problems for almost 6 months!!! I acquired a small calcium reactor and Kalk stirrer at the same time. <...> However, due to the large amount of SPS kept, both units could not keep the Ca & KH levels up. So, I dosed KH & Ca manually. <....!> Unfortunately, I over dosed frequently, and had constant precipitation issues. I went into the cycle where dosing Ca will depress KH, and dosing KH will depress Ca. I did not know why at that time, but I understand why now.  Anyway, few months later, when I finally know where my issue is, I dosed huge amounts of Mg. In total, I dosed about 8kg worth of Mg, before I was able to keep Mg at 1500ppm till now. Also, I upgraded to a much larger calcium reactor, and sold both the old calcium reactor and Kalk stirrer.  After that, I was able to maintain Mg at 1500, Ca at 450, and KH at 12. This was my value for > 6 months till few days ago where I lowered the values to the above stated.  So, my guess is that during the months of over dosing, my sand clumped up without my knowledge. Also, since I did not touch the sand bed much, it might have already clumped for > 6 months. Good news is that I've not noticed any negative factors to date.  I searched for advice and what I got was these ? 1. Lower dKH & Ca. It's said that if these levels are lowered for extended period, the clumps will loosen. <Mmm, not likely> I already lowered from dKH of 12 and Ca of 460 to dKH of 10 and Ca of 400. However, since 80% of my corals are SPS, I dare not lower the levels any lower. 2. Remove the clumps and replace with fresh sand. Today, I tried to remove clumps of the sandbed. The top 1 inch is still loose. But below that, the sand sticks together, and I can ?peel? off one sand grain at a time. After searching for 10 minutes, I could NOT find the edge to the clumps!!! I even felt near the front of the tank ? no use. There is no gap between the glass and the sand clumps. It's as if it is ONE BIG ROCK!!! OMG!!! I fear that it had fused with my egg cart. The top egg cart is only 2 inches below the surface. 3. Introduce sand shifting gobies. I'm not sure if this will help, so, have not done so yet. <I wouldn't do this> Currently, my water condition is very nice ? SPS color and growth is nice ? soft corals and other corals are opening quite big ? fishes are healthy and brightly colored ? in short, I've got no issues now. Also, since I've already got a remote deep sand bed, I would not have any NO3 issues even if the Jaubert sandbed in the main tank is not ?working?. QUESTIONS: 1. The top 1 inch is lose sand. Below that, it's solid. Since my sandbed is 4-5 inches deep, do you think the clump is all the way to the bottom? <Possibly... but not likely> 2. If yes, since it is already one BIG rock, can I just leave it alone?? Will it crash my tank??? <Will not crash your tank... I would try "poking" parts every week, water change interval with a sturdy dowel (maybe a wooden or acrylic one)... otherwise... I'd keep monitoring your water quality, not worry... the compacted sand should "loosen" over time...> 3. If no, I assume that the clumped sand will cut any oxygen from diffusing to the lower layers. Will this somehow produce hydrogen sulphide or some negative factors which will affect my corals and crash the tank? <Not likely a problem... think about how deep some Sandbeds are in the wild...> 4. I was told that the Ca is actually the key factor. So, should I increase dKH from 10 to 12, but keep Ca at 400? I find that my SPS seems to color up a bit more with higher dKH. <I would read a bit more, proceed cautiously with any changes... some calcium, in proportion with magnesium and alkalinity is all you really need to focus on... not specific limits... really> 5. By keeping my dKH at 10 or 12 and Ca at 400, will the sand clump really loosen and solve my problems?? <Mmm, no... but reductive events in the lower depth will solve themselves over time> 6. Should I introduce any sand shifters? If so, what? (Note: sand grain is 3-5mm) <I wouldn't> 7. And finally, the question that I dare not ask ? should I tear down the tank with a hammer and chisel?? <Heee!> Worried ... sigh. Thanks for your advice. Jason <I might (actually) add a bit more fine sand on top of what you have... and definitely not worry. Bob Fenner>

Re: Sand Clumping 05/20/08 Hi Bob, <Jason> Thank you very much for your advice. Now I can sleep better at night knowing that my tank will not crash due to sand clumping. <Such is rarely the case> Today, I took a long piece of PVC, and fitted a T-joint at one end. I used this to press into the sandbed. I can feel the crunching of the sand. Looks like the problem is not as serious as I thought : <Ah good> 1. Taking a small cube of clumped sand between my fingers, it crumbled with light pressure. <Is fine> 2. Since my sand grain is 3-5mm, there are still holes between the clumped sand. I think enough for water diffusion and the sandbed to work its magic. 3. Assuming that the clump sand was there for so many months, any "bad" stuff that could have developed would have been released with my action. The only reaction from my SPS was slight sliming due to the excess detritus kicked up. Other than that, everything seems normal. <Yes> After working on all exposed sandbed, I found about 70% was clumped. I was just wondering if I should work the sandbed below the rocks. After your advice, I'll not do so. Phew. <I would only do "part" of any such movement, crushing at any given time... IF your rockwork is placed as you like, I'd leave this area be> With this, I think we can consider it case closed. Again, thank you very much for your time, effort, and concern. Keep up the good work!!! Best regards, Jason <And you, Bob Fenner>

Sand bed... input re depth, SW  12/5/07 Hello I've read through the FAQs on sand beds (it's taken me nearly a whole work day) and the majority of you guys seem to be in favour of having either a half inch substrate or more than 4 inches. <Yes> Then again, there are some who seem to like 3 inches. What everyone seems to have overlooked is the reasons why. <Mmm, these speculations/assertions are posted as well...> There is no clear explanation anywhere. <The thought is that avoiding intermediate depths to stave off the negative effects of trapped material, an-hyp-oxia... and the resultant metabolites of low/no oxygen decomposition thereof> The reason I wanted to know this is because I have a 2-3 inch sandbed (running for 2 years) and have had zero problems with it. <Easily done... the "rule of thumb" depth statement/s are just that... depending... on the actual physical and chemical make-up of substrate, the particulars of the individual hobbyist maintenance, foods, feeding, circulation... many other factors... any depth of substrate may be fine to fantastic...> My nitrates are always zero. The sand is almost always beautiful white; where other tanks I've seen (including the LFS tanks) have deeper Sandbeds which are just plain eyesores due to the amount of BGA growing all over them. My substrate puts them to shame. Also it would seem like you dislike cleaning the substrate. Well the only problem I've had with mine is the occasional diatom patch, and what I do, will likely shock you, but it works a treat. I siphon this sand patch out and repeatedly rinse it with fresh tap water! Once again, no problems at all. I just wonder if people are being led astray? Or have I just been lucky? Please explain. Thanks. <Thanks for your input. Bob Fenner>

55 gal Saltwater aquarium... substrate, too deep/thin and... maint.   11/3/07 Hi, I have a 55 FOWLR (well one piece of coral, it was a reef tank till I got the Paupen) <?> gallon saltwater tank that's been running for 1 1/2 years. My stock is a Paupen Toby, <Papuan?> Royal Gramma, Firefish, Diamond Watchmen Goby, a piece of Montipora coral, 6 scarlet hermit crabs, and 5 Nassarius Snails, and in the near future a Scooter Blenny. All my tests show everything is fine for water parameters. My problem is that my Diamond Watchmen has quit sifting sand and will only eat frozen foods. My sand has turned brown in some spots and turned into hard clumps and when I break them they let out a brownish cloud into my water. For sand I'm using Super Naturals Torpedo Beach sand. My question is what would cause this and is there any fish that would take care of this? <... not familiar with the sand brand... likely best for you to stir, possibly vacuum regularly...> I can't have any snails in the tank, the Puffer destroys them in a matter of an hour or so, except the Nassarius Snails. I've looked at a sand sifting star and I don't think my sand bed is deep enuf (3") <Is fine... a good depth> to support one and I don't think the puffer would let it live. Thank you for taking time to read my e-mail. <Please read here: http://wetwebmedia.com/marine/setup/index.htm the sixth tray... on Marine Substrates. Bob Fenner> Black Sand Nano 9/26/06 Hello folks, <Hi> A friend turned me on to your site, great info.  I am in the process of setting up a 29 gallon oceanic cube. I wanted to use the fine black Fuji sand.  This is not live sand, so how does this figure in the equation of setting up a mini-reef?    Thanks Stephen <Should work fine, if I remember correctly it is calcium based so you will get some buffering from it and the critters from your Live Rock will populate it with time.> <Chris>

Sand Bed Size 9/21/06 Hey guys. <Hi> Firstly as always, thank you for such a helpful web site. Since my last question I have gained much information from your FAQs and informative articles. Crikey! You guys are good and probably over worked! <Bob is quite the task master especially when he makes us travel to tropical destinations to dive.  It is a labor of love I assure you.>    Just a quickie. With reference to my new 4x2x2ft reef tank, which would you choose for a less than1/2" deep bed: A)  CaribSea Aragamax Sugar Sized Sand   Grain size 0.1 - 1.0 mm. or..... B)   CaribSea Special Grade Reef Sand    1.25--1.95 mm diameter grain size. And of course why? :o) To be honest I am leaning towards the Aragamax due to the fact it simply looks better.  Being from Australia (hence the crikey!) these are the only two CaribSea products I can get my mitts onto. 'Tanks' for your help (ha ha I'm sure that one has been done before)<G'day Mate> All the best Garth <For a shallow bed like that either will work just fine, the choice is really just what looks best to you.  If you decide to go with a deep sand bed the sugar fine works better, so for future flexibility I would go with the sugar fine.> <Chris>

Redoing Substrates 9/13/06 To All: <Hi> I'm getting ready to redo my substrates in my 90 gal reef tank. I have had problems in the past with nitrates sometimes high but can be controlled with water changes. <Best method> Currently I have a 5 inch crushed coral bed with underwater filter powered by one 110 and a 70 aqua clear power head on each corner. along with a canister filter and skimmer). <What we call a nitrate factory.>  UG filters are not used much anymore for this reason, among others.> After reading endless amount of info on your site I just wanted your opinion on what would be the best substrates for me to use. I would like to stick with a substrates for some of the goby's and other creatures that enjoy digging. <I like using substrates in the main tank.> I was thinking of going with 3 to 4 inches of live sand. <Good, sugar fine is best.> I have 75lbs of live rock that I use for my reef too. Should I use underwater filter or just place the sand on the bottom?? <Sand on the bottom, the UG filter will not work with sand.> And should it be mixed with crushed coral or something else?? <Nope, just sand.> This seems to be the most difficult question to come up with an answer for. There is so many ways to setup a substrates. <Many different ideas out there, I like a simple 3-4 inch thick layer of sugar fine sand.> I'm sticking with mostly soft corals since I currently don't have a metal halide light. <Sounds good.> Thanks, J.R. <Anytime> <Chris> Replacing Marine Substrate - 09/11/06 Hello again, hope all is well. <<Well enough...thanks>> Quick question, I would like to replace my substrate with fine sand (about 2-3 inches deep), bad idea? <<Not a bad idea...but I recommend a minimum of 4" is recommended to allow sufficient depth for nitrifying/denitrifying processes>> Would it be best to use Carib-Sea Aragalive? <<Not in my opinion...a waste of money.  Any "dry" sugar-size aragonite will do>> My current substrate is a fine sand, crushed coral mixed and the main reason I want to change it is I am not happy with the look (the crushed coral always ends up on the top). <<Okay>> I think that if I tried to add the fine sand on top I would eventually end up with the crushed coral on top again, and would smother most existing bacteria.  Or would it be possible to siphon out a third of the current substrate at a time and replace it with the new substrate over a period of a few months? <<This is a good approach...2-3 weeks between will likely suffice>> By the way it's a 90 gallon tank with 20 gallon sump.  Thanks, I'm sure I'll have another question in a week; I need to stop thinking so much (obsessive compulsive disorder). <<Ha!  No worries mate...be chatting.  EricR>>

Re: Replacing Marine Substrate - 09/12/06 Ok thanks, one last question. <<Alright>> By siphoning current sand I won't be letting off harmful gases in the tank will I? <<Is a possibility...especially if your sand bed is covered with rock/water flow has been insufficient to keep detritus in suspension.  My experience with this has been that pockets of "gas" (hydrogen sulphide), while highly toxic, quickly dissipate from the water.  It will make your nose wrinkle for sure, but I've never experienced problems with livestock from disturbing small pockets of this gas.  Hobbyists remove/change/modify their substrate all the time.  Supply vigorous water movement (but no need to create a "sand storm") during the operation and you'll likely incur no problems.  EricR>>

Re: Saltwater tank problem  9/10/06 One final word on this. Do you think it is possible/advisable to run the tank without gravel or is there a need to have at least some type of media on the bottom. Thanks for your time. Tom <<Tom:  Many people who try to grow hard to keep SPS corals swear that it is easier to keep them in a bare bottom tank.  In all other situations, it's mostly a matter of personal preference.  In the saltwater world, most people don't add gravel to their tanks.  They usually use sand. What type of gravel is it and where did you get it from?  If it is something that is not normally found in an ocean environment, it might be contributing to an increase in phosphates and nitrates in your tank.  Best of luck, Roy>>

Re: Saltwater tank problem  9/10/06 Thanks for the fast reply. Forgot to mention that I had the brainstorm to set up the tank without any gravel thinking that it would keep the tank cleaner. Any idea if this may have had a hand in my troubles? I've since added gravel. <<Thomas:  Did you note the problems after you added the gravel?  If so, the cloudiness could have come from dust that was on the gravel.  I would suggest keep changing the water and testing the parameters.  Depending on what it is made of and where it came from, some gravels can add to your phosphates and help increase your nitrates.  If it is a fish only tank, nitrates shouldn't be too much of a concern.  Best of luck,  Roy>>

Sandstorm blues!  - 09/10/06 Hi guys, I hope you are all well.  I have a somewhat vague/non-specific question but hey, if I don't ask'¦'¦ I have a 47G reef (mostly fish and inverts though) aquarium with 6' DSB and about 30Kg well-matured live rock.   I am running a small CPR Aquafuge (with DSB and Chaetomorpha), an AquaC Remora and 2 Seio M620s (lots of clutter then!)  Now, my current problem (apart from having not chosen to go down the sump route!) is that I have lots of floating 'detritus' in the tank due to the DSB and (theoretical) 26X water movement provided by the Seios as well as a relatively high bio-load.   My question is, should I accept that there will always be a substantial amount of tiny floating 'bits' in the tank (am I right here?) or, alternatively, I have both an Aquaclear 50 and a Eheim 2026 Pro II at my disposal - any ideas? I thank you in advance of any (undoubtedly good) advice you'll give, Steve Morse. <<Steve:  To avoid a sandstorm, you can play with the placement of power heads.  If you have two streams of water crashing into each other, it can weaken them.  If you don't like floating detritus in the water, you can place a filter pad (or filter sock) in the system.  You would have a change it and clean it frequently.  Otherwise, your nitrates will probably shoot up.  How long has the tank been running?  Usually once a tank has cycled, even sugar fine aragonite will not stir up so easily due to biological activity.  Best of luck, Roy>> Re: Sandstorm blues!   9/11/06 Hi! Thanks for the advice - in response to your own questions, the tank is over a year old and the powerheads are aimed towards each other although some live rock is obstructing somewhat.  I guess, in a nutshell, what I was asking is; given my tank and the availability of both an Aquaclear and Eheim canister filter what would you do (for example which - if any - would you use and what would you fill it with?)  Bearing in mind that I already have a shed-load of biological filtration (my Nitrates are always nil) and that I have to be careful not to over-clutter the tank.  Finally, please note that it isn't so much a case of lots of floating sand but more intermittent 'bits' of waste (still unsightly of course!)  Many, many thanks, Steve Morse. <<Steve:  People that use canister filters for an occasional cleanup, run them with carbon, mesh pads and other filtering materials.  Personally, if you really want one, I would suggest you only run it occasionally.  That way, a lot of the free floating critters can circulate through your tank.  From personal experience, my Eheim products have lasted longer, and the pumps are quieter, than Aquaclear.  Best of luck, Roy>> Thumbs up or thumbs down?  9/6/06 Dearest Bob. <Heeee! Call me Caesar!> I would just like to have your current take.  I am setting up a 90 with 55 sump. For the moment I would like a heavy bio loaded fish only. I was thinking remote 10 inch sand bed in 55 sump but bare bottom display. Just wanted to know your vibes towards this or would you go for DSB in sump and DSB in display as well..? <I'd put just some... an inch or less substrate in the main tank... and remote the DSB as you state. The gravel for disallowing reflection...> Thanks Bob. Your reaction will influence me directly.  You're the god of my tanks. Tristan <Actually... I'm more like a/the prophet... and you're the god... Buddha Bob> Band Sand Algae   8/24/06 WWM, <Lee> Great site (thanks!) -JK-. I needed some expert advice on my sandbed, lately it is becoming pretty ugly and seems to be getting worse. The problem is a red algae (possibly Cyano) <Likely so> is spreading in my dead spots. I have enough Powerhead flow, I just cant seem to get the randomness it needs. I have hills and caves, and the algae grows in places my powerheads do not reach. I can't vacuum the sand in the areas the algae grows because of  the rockwork, like I said, its in caves and  under ledges. Just want some advice so I can get my sandbed to look as nice as the rest of the tank.. L <Please read here: http://www.wetwebmedia.com/bluegralgae.htm and the linked files above. Bob Fenner>

New Tank, New to Salt Water 8/17/06 Mixing substrate types/sizes   8/17/06 I have a question about my first saltwater fish tank. I just set it up yesterday and I don't really know a lot about saltwater fish tanks. <Read, read, read and read some more before adding any livestock.> I have a 29  gal fish tank with about 20 lbs of crushed coral in it. Can I also put some sand in it or will that just be stupid? Thanks a lot   ~TREY~ <Mixing substrates is generally not a good idea.  You get worst qualities for both this way.> <Chris>

Sand or crushed coral, maybe both? 8/8/06 Hi, <Hello> I have a 55 Gallon fowler tank. Not much in it right now,50 pounds live rock, 3 turbo's,6 red and blue leg hermits,3 Astraea snails and 1 clown. The tank has been set up now for about 3to4 months. My sand bed is made up of 30lbs Aragamax sugar sized sand mixed with 20lbs live sand. <How deep is it?  I'm guessing 2+ inches.> My problem is that the sand gets so dirty looking (brown algae and snail poop I think)  when I try to clean it the sand gets EVERY where by the time it settles my live rock is just covered and looks like crap. I hear good things about sand helping to control nitrates, that's why I went that way. <At the right depth it can be quite useful for nitrate reduction, 3+ inches at least.> But I was wanting to maybe go the crushed coral route. <Can be problematic, trapping detritus.>  I don't know any body that has a saltwater tank and the LFS in my area are not worth going to "they don't even sell RO water" so I thought I would ask some one who could help me out a little!! <Hopefully> Should I try the coral or stick with the sand? <I prefer sand, either under 1 inch or over 3.>  Can you mix the two and have the coral for the top layer? <Worst of both worlds, I wouldn't recommend it.>  Is the coral easier to keep clean? <Not really.>  Also one more question I did some reading just incase I did go with the coral about keeping nitrates down and I came across a DIY project called a coil denitrator that claimed after two months of cycling it will help keep nitrates down ever heard of anything like this? <Yes> Maybe worth trying? <Lots of work, mixed results at best.  Water changes and a deep sand bed are easier in my opinion.  Give this a read for more http://www.wetwebmedia.com/deepsandbeds.htm > Thanks for any help Brian <Anytime> <Chris>        

Replacing a damaged acrylic tank   7/18/06 Hi Crew, <Tom> We have a healthy 120G reef setup for 2+ years now, much of the credit goes to the WWM database.  Around 170lbs live rock, 1-1.5" sand/rubble bed, several good size SPS (up to 12" across), <Nice!> a few nice LPS, xenia, 6" derasa, Lysmata shrimp, few dozen small hermits and Nassarius snails.  The fish range from about 4.5" down to 2.5", and are a purple tang, pacific blue tang, flame angel, pair of Percs, yellow watchman goby, royal Gramma, twinspot/yellow hogfish, yellow Foxface - all healthy & active.  Salifert tests indicate quality & stable water. So what's the problem?  The old tank is giving out <?!> so we need to move the contents & gear across the room to a replacement tank of about 130G. Could it be done as simply as the following plan? 1. Pump about 1/2 the old tank water into the new tank. 2. Keep the old tank circulating with powerheads. 3. Put about 1" of new sand into the new tank. 4. Seed the new sand with a few pounds of the old sand and let settle for a 1/2 hour or so. 5. Move the rock and coral & arrange in the new tank. 6. Move the fish and remaining animals into the new tank. 7. Pump the remaining water into the new tank. 8 Top off the new tank with enough saltwater, probably 10-20 gallons of aerated, buffered saltwater. 9. Keep the new tank temperature stable & circulating with powerheads while we move the existing gear (sump, chiller, pumps, skimmer, lights, Ca reactor, etc.) <Sounds good, complete... will you move the remainder of the substrate ultimately into the new system?> We've budgeted a day for the move and the next day to work out issues, and another day for wrapping up.  Is this plan OK?  What else could we do to minimize the stress on the animals and make this a successful event? <Plenty of towels, buckets... a reduction in any/all other distractions> Is the new tank likely to have any re-cycling issues? <Likely not> Thanks, Tom <Welcome. Thank you for sharing. Bob Fenner> Re: Replacing a damaged acrylic tank  - 07/18/2006 Hi Bob, <Hello Tom> The current substrate is a mix of sand & rubble, and the plan was to use a kitchen colander to sift out rubble before putting the old sand in with the new. <Ahh... I see>   In the new tank we want sand only, no rubble.  Given the sifting & handling of the old substrate, do we need to be concerned about causing enough of a substrate die-off that we should just use enough to re-seed the new tank, or would it be OK to reuse all of the old substrate, after it is sifted? <Perfectly fine to use the finer-only bits... the bacteria will survive in good numbers if you rinse this with only the old system water. Bob Fenner> Thanks, Tom Maintenance/Substrate Cleaning   7/18/06 Your site is great & have used it for about 8 months now, learning so much.  Thank you. <You're welcome.> Have done searches & FAQ's, but have these Q's: 1) When I vacuum <vacuum> my substrate (Caribbean product, I believe aragonite?), I think I may be sucking out too much of the substrate itself.  How much, if any, of the substrate should actually be removed from the tank when siphon cleaning? <Very little, if any.> I started with about a 2" deep bed 5 months ago and am now down to about 1/4". <Ah, a substrate guzzling tank.> 2) I have not been regularly rinsing & reinserting the sand I've removed (too lazy after cleaning red slime off of live rock), <Can't be lazy in this hobby.> so now I have a bunch of sand that has been sitting in a bucket for weeks/months.  I want to put that back in the tank (slowly, parts at a time) but think I should probably clean it since it's not completely dry.  What is best way ?  Should I use a bleach/water combo, rinse , and then let it dry in the sun ? <I'd put the substrate in a five gallon pail and just keep rinsing with water, no bleach or other chemicals.  Fill the pail with about two inches of substrate at a time, much easier, quicker. I like doing this outside with a hose.  Shouldn't say "I like", rather, "doing this outside".> Thanks, <You're welcome.  James (Salty Dog)> Paul

Halimeda Leaves    7/13/06 Dear Crew, <Paul> I have two questions regarding a batch of Halimeda leaves that has accumulated on the surface of my otherwise sugar-fine aragonite substrate: <Okay> (1) Will the leaves trap detritus and contribute to a high nitrate & phosphate problem? <No, not likely... in fact...> (2) Will the leaves harbor small organisms that can sustain a Mandarin Dragonet should I acquire one? <Will likely help, and...> In other words, I am trying to determine if the dead Halimeda leaves have any usefulness before I siphon them out. <I would leave them, enjoy their beauty and utility. Are almost completely calcium carbonate... of good shape...> My tank is a 75-gallon reef tank with plenty of live rock, coral, anemones, and 12 small (2" long) fish that unfortunately don't eat algae.  I've had 20 of these fish (Blue Damsels, Pajama Cardinals) but I've recently reduced the fish population to 12 in an attempt to control high nitrates, phosphates and hair algae.  There is also a 29-gallon refugium with a small batch of Chaetomorpha that does not grow as fast as the algae. Thanks very much, Paul. <If we could easily harvest such calcareous material and offer it as purposeful substrate... it would sell. Bob Fenner>

Home Depot Sand?   7/8/06 Hello! <<Hello!>> I've been through your FAQs on sand and before I pay the $36 for the 40 lbs of sand at my LFS, I just had to check on this sand called Colorscapes at Home Depot. <<Hmm, don't recall hearing this was calcareous...but that doesn't mean you can't use it if it's not, just won't get the benefit of a buffer.  Best I can offer is to test this sand yourself.  Place a pinch in a small container and add some white vinegar...if it bubbles/dissolves the sand then it is calcareous>> I've used Southdown in my prior aquarium and it seemed to work well (after rinsing and a week of nothing but cloudiness)! <<Mmm, yes indeed...and is what I used as well (950lbs of it)>> I need enough sand for a 120 gallon tank, the calculator on another site says 131 pounds should give me 3".  Any advice? <<You say you've read up on sand, but have you read up on DSBs? ( http://www.wetwebmedia.com/deepsandbeds.htm)>> Regards, EricR

Adding Additional Substrate - 06/29/06 Hello again, back to ask another question. <<Hello Ryan, EricR here again>> I recently did something that Eric R. told me not to do (which is went from a 55 gallon to 90 gallon in one day, added seeded sand and my old sand from the 55 gallon on top) so far I have not had any problems although I am worried because he advised me against doing this in a day. <<Was just that Ryan...advice.  Is ultimately up to you to decide a course of action>> Anyway my question is, I am not happy with the sand (actually crushed coral that was under the sand in my 55) being on top, not as nice to look at, can I slowly add a few pounds of CaribSea Bahama Oolitic fine grain sand at a time (I know its not actually live but no dust)? <<Shouldn't be a problem...though the fine sand won't likely stay on top...will eventually mix in>> Just FYI I did this one day change over a week ago and have been monitoring all parameters in my tank which are ammonia 0, nitrite 0, nitrate 0, phosphate 0.1, Alk 9 dKH, calcium 400 ppm, PH 8.3.  So is something bad still likely to happen? <<My advice previously was to allow some time to monitor/allow for the new system to cycle to reduce risks before adding your livestock.  It looks like you may have had enough "cured" material to transfer to the new system to avoid a full-blown nitrogen cycle.  At this point, I would keep a close eye on water quality and keep a batch of seawater and some chemical filtration media (Poly-Filter) handy in case a large water change becomes necessary>> All of my corals look better than they did in the old tank, my anemone looks great, my fish are fine -no Ick, snails are fine and my cleaner shrimp is good. <<Am glad to hear>> I have been feeding quite lightly to let bacteria populations get back to normal levels before I feed regularly. <<I think you can begin to return to a normal feeding regime...monitoring water quality along the way>> I have attached a picture of the tank, just for fun. <<Looks very nice, though it is so large I'm not sure if we'll be able to resize/post.  For future reference, please send images as bitmap or JPEG attachments...of a few hundred KB in size>> Thanks I am extremely interested in what you think, Ryan Nienhuis <<Keep a close watch and the tank will likely be fine.  Regards, Eric Russell>>

Sand Beds/Maintenance   6/9/06 Hello, I currently have a 90 gallon FOWLR tank.  The current inhabitants are 2 yellowtail damsels, 2 clowns, a hippo tang, a royal Gramma, a skunk cleaner shrimp and an assortment of crabs and snails.  All live in relative harmony.  I recently wanted to add a good sand sifter because, even though my Nassarius snails were doing a good job, I wanted something to more actively clean the surface of the sand.  I went out a purchased a diamond goby.  God bless the little guy because from the moment I put him in the tank he went right to work.  The problem I have is the tank is a little cloudy now because he is always at it.  Will the constant cloudy water have any ill affect on the rest of the inhabitants in my tank? <Could very well, if the sand bed is stagnant, that is, not enough critters to keep it stirred up.  If that's the case, the goby may/will cause hydrogen sulphide gas to be released into the tank. And this, is not good.  Is a good practice to vacuum the sand bed during water changes to prevent this and improve water quality.> And of course thanks in advance and for the great site. <You're welcome.  James (Salty Dog)> Thanks Craig

Dirty Sand 6/5/06 I have a brown red film that will go away at night and comes in about 2 hrs after the lights come on. What would be causing this? Is it the lighting I am using. I have a power compact 260 watt with 2 actinic blue and 2 12k lights? <Most likely Cyanobacteria, a photosynthetic bacteria.  Can indicate a nitrate or phosphate problem.  Also common in new tanks and will often cycle out after a while with no action needed.> <Chris>

Dirty sand Part II 6/6/06 Thank you for the quick reply. <Sure> Also the bacteria looks like it is covering the live rock I used a soft bristle brush to remove what I could. I have had nitrates staying at around 10-20ppm I just started protein skimming Sunday. <Will help lots, hopefully a quality skimmer.> I am feeding 2x a week right now.  Is there any other suggestions? <Water changes, nutrient export.> My LFS said to leave the lights off for 2 days. <Treats symptoms, not cause.> But I have a Sebae anemone will this harshly effect it. <Yep> Also is SeaChem's Purigen a good nitrate reducer.  <Water changes and a deep sand bed are better.> <Chris>

Dirty Sand Part III 6/7/06 Well I hope it's a quality skimmer it's made by Red Sea the Berlin-airlift 60 it seems to be working great. <Check out http://www.wetwebmedia.com/ca/cav1i1/protein_skimmer_impressions.htm for more on skimmers.> Slow moving thick foam... Also how deep is deep? <3+ inches.> Which L.S. is a good choice? <Sugar fine calcium based sand.> Thanks you so much! <Welcome> <Chris> Adding live sand  - 05/29/06 Hi crew, <Hi> I have a 90 gallon FOWLR with crushed coral at the moment. I'm interested in housing Jawfish (Yellowhead) and wrasses (red Coris) and realize that they need a sandy substrate. My CC depth is ~1.5" now, and my plan was to add sugar-fine LS to a depth of 2.5" or 3". This results in a couple of questions. 1. Would these guys be ok in a mixed CC/LS setup and this depth, or do they need a complete sand substrate? <The problem is that the CC does not stay at the bottom, it will rise to the top of the sand, making problems for the Jawfish especially.> 2. I've read up on your site about the LS depths recommended (1" or less for decorative purposes, 4"+ for DSB). I'm very diligent about regular water changes (~15% a week w/ vacuum) and monitoring nitrates, so I'm more concerned fish happiness than nitrate reduction. <Jawfish make mostly vertical burrows, so 3+ inches of sand is best.> 3. Tied to question 2, are there additional drawbacks to this combination and depth I should investigate further? <I would remove the CC, and replace with sand.  A pain but really the best long term solution.> Thanks for all of your help and support. Ian <Chris> Vacuuming Substrate, Algae, Dead Fish, LFS Water Testing - 05/30/06 Hi crew, <<Hello!>> Ok, I have read all the vacuuming FAQ's and still have no definitive answer to the question of whether I should be vacuuming the substrate in my 46 gallon reef tank. <<My preference is to NOT vacuum the substrate in reef setups...many beneficial organisms will be destroyed/removed.  If your substrate is of a fine material and you have good strong flow it should be of little concern as detritus should stay in suspension long enough to either be eaten, or removed by your filtration system>> It is brownish on top and I have a sand sifter goby that works his buns off (although he does dump his sifted sand on my live rock mostly, I hate that), also various crabs and snails. <<I know what you mean about the goby "crop dusting" your rock/corals...is typical of many of the "Sleeper" variety (Valenciennea sp.).  I can suggest you try a Dragon goby (Amblygobius phalaena).  In my experience these gobies will usually not sift/dig so deep as the sleeper gobies, and tend to stay lower/closer to the substrate while sifting meaning less "fallout" on your rock/corals>> I don't know what kind of snails but I am pretty sure they aren't Astreas since I couldn't find any to buy.  I also have a considerable amount of "Green Algae" that I think is hair algae. <<Hmm...do you filter all your top-off/salt make up water?>> I have a good skimmer that works well, my water parameters are as follows:  Salinity 1.021 to 1.023, <<I would raise this to NSW levels of 1.025/1.026>> Temp 79-80, Ammonia-0, Ph 8.2, Calcium 470, <<You're flirting with the upper limits here...I would let this fall to about 400ppm>> Alk 3.5, Nitrite and Nitrate-0, Phosphate reads 0 but I wonder if the algae isn't taking it up so it doesn't show on the test. <<A possibility.  Perhaps you can add some Poly-Filter to your filter flow path?>>>> My normal water change regimen consists of 5% twice a week and I only use RO/DI from the LFS for top off and prepared salt water from the LFS for changes. <<Mmm, a couple thoughts here.  Change your regimen to one 10% change per week, or even a 20% water change every two weeks...more effective than the tiny frequent changes in my opinion.  Also, test the water (both fresh and salt) you are getting from the LFS.  I'm not suggesting they are doing anything wrong, but YOU need to be confident this water is not causing you any problems>>   My bio-load is small just the goby, a lawn-mower blenny (that isn't mowing much), a shrimp and a frogspawn coral.  I had other fish but over the past three months they have all died mysterious deaths but that is another email I guess. <<This would seem to indicate more than just an algae problem>> In case you are interested they were two clowns (died at different times), a royal Gramma, a yellow tang and a six lined wrasse, all died about a week to two weeks apart.  No clue from the two LFS (they also tested my water several times and always pronounced it wonderful) I use on why because my water parameters are stable at what you see above except the Alk gets a little low from time to time. <<Still, all those fish dying means something was/is poisoning your system.  The low alkalinity is likely due to the extremely high calcium...the two are generally considered mutually exclusive, I'm surprised neither LFS has said anything to you regarding this.  Please do some reading here and among the indices in blue at the top of the page: http://www.wetwebmedia.com/alkalinity.htm >> The two clowns looked a little like they had developed HLLE but were eating Mysis shrimp and Cyclop-eeze with garlic drops and Selcon almost up until the end.  The others looked perfectly healthy, just slowly got listless and died, no spots, etc.  If you do have any ideas I would be interested to know them. <<As stated, it sounds like some environmental/poisoning event...might even be the fish were "damaged" when you acquired them...do you employ any chemical filtration (carbon/Poly-Filter)?>> So I am waiting a few weeks to try to add more victims and in the meantime am trying to take this time to get the tank and rocks as pristine as I can.  So I think I am doing everything right except I don't vacuum the gravel because my LFS has told me not to. <<I am inclined to agree>> He says the goby should do the job.  He apparently needs help. <<Perhaps the substrate is too "course" for the goby>> Should I be vacuuming the gravel or not. <<If this is a shallow substrate (less than an inch) of course material then yes, you can go ahead a lightly vacuum during water changes...if this is a fine substrate, if you have a DSB, then no, I wouldn't vacuum, it is not necessary in the first instance, and is not desirable in the second>> Thanks for your help then, now and in the future. Debi <<Debi, all things considered, I strongly recommend you get some test kits of your own and test the water you use from the LFS...if for

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