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FAQs on Marine Alkalinity Additives/Buffers

Related Articles: pH, Alkalinity, Marine Alkalinity, Understanding Calcium & Alkalinity,

Related FAQs: Marine Alkalinity 1, Marine Alkalinity 2, Marine Alkalinity 3, Marine Alkalinity 4, Marine Alkalinity 5, Calcium and Alkalinity, Phosphate & FAQs on Alkalinity: The Science of Alkalinity, Importance, Measure, Sources, Troubleshooting/Fixing, Products by Name & FAQs on pH: Importance, Science, pH Measure/Test Gear, pH Controllers & pH Buffers/Buffering, pH Anomalies (Troubleshooting/Fixing), & pH Products by Name, Manufacturer,

Mmm, water changes, careful feeding, use of skimming (to remove reductive compounds), perhaps a calcium reactor, DSB/suitable substrate, additives. Kalk by itself... NOT a cure-all http://advancedaquarist.com/issues/may2002/chem.htm


I've read that i can use baking soda as a buffer -- is this true and is it as good quality as the buffer sold in the shops.  It certainly seems a bargain 

Helen, by email

As with most chemicals Helen, there are stated and implied purities'¦ Reagent, Laboratory, Technical are common labels, the last costing less and containing some impurities but fine for most industrial uses. Baking soda, sodium bicarbonate as 'food grade' is fine for human consumption as well as aquarium use. However, it should be pointed out that commercial buffering compounds contain other materials of use; carbonate/s, sometimes borate/s and other compounds and anti-caking agents to prevent the materiel from clumping into a solid. Baking soda by itself can be of use in most systems, but it will not boost pH sufficiently in most cases, and its sole use calls for more diligent monitoring (daily sometimes) compared with an aquarium-use-formulated product.

If you intend to use baking soda by itself for adjusting and/or maintaining pH, DO blend this into water to be used for make-up, replacement for change-outs (i.e. don't add directly to an established system as a granular/powder), and DO monitor KH on a regular basis.

Kalkwasser no PH impact
Looking for your thoughts on this one. My tank PH has been dropping to around 7.6 at night.
<Mmm; poor buffering capacity... might drop some... like a tenth of a point, but not much more>

I wanted to try and boost my numbers a bit so I have been dripping Kalk on doser throughout the day to essentially compensate for the tank evaporation.
<Mmm; won't buffer, hold pH up...>

Been running it for 2 days now and the PH is still bottoming out at 7.6 at night with a high of 7.9 per day. Any thoughts as to why its not working?
<Oh yeah mate... time for you to try a mix of carbonate/s, bicarbonate/s. A plug here for SeaChem's products: https://www.seachem.com/marine-buffer.php
And do look up the different twixt pH and alkalinity.... BobF>
Re: Kalkwasser no PH impact

Thanks Bob. I actually have this on hand so can give it try.
<Ah, good. DO add to new, change out water and plan on changing, elevating BOTH pH and alkalinity slowly... no more than 0.1 pH point a week>
Right now the Alk level in my tank is 8.7DKH so I have some room to play around with. Is the marine buffer something that I will need to add constantly/daily or is it more of a monthly fix if the tank loses the
buffering capacity?
<IF your pH and/or buffering capacity is lacking, add a/the buffer every (weekly?) water change. AND do look at where you're lacking such... too olde substrate, live rock (can be added to, substituted), a lack of oxidative mechanisms (use of chemical filtrants, ozone, UV...), too much reductive mechanism addition (foods, feeding...). Bob Fenner>
Re: Kalkwasser no PH impact      4/14/20

Did some playing around with the system and the low Alk is definitely related to the cal reactor.
<... what's the pH of the material coming out of the reactor? This is a CO2 type?>
Just dosing 2 part ph is at 8.2. Because my tank is stocked I am dosing 250ml's per day and may even need to bump it up to 300. Is there any downfall to running a calcium reactor at a lower rate and then compensating the difference with 2 part to avoid dropping the PH in the tank.
<There is not; no disadvantage. Even Daniel Knop who sells his name to have reactors made uses such>
Seems a lot of people mix two part and Kalk but not two part and reactors.
<Welcome. BobF>
Re: Kalkwasser no PH impact      4/14/20

PH out of the reactor was 6.0 with an effluent of 130ml per minute.
<That's too low... I'd adjust the carbon dioxide downward till you have an effluent pH of about 6.8>
Unfortunately TLF's reborn media is no longer available and I had to switch to ARM.
<My ex wife used to distribute Knop Products in N. America... I've picked up literally tons of their fab media>
This is when all my problems started. Reborn melted at a higher PH's so I was able to maintain the same DKH of the effluent at 6.5 verses
6.0. The difference took my tank ph from 7.8 to 7.6.
<... Again, I'd be adjusting the CO2. B>
Re: Kalkwasser no PH impact      4/14/20

At 6.8 the media wouldn't melt sufficient to get any meaningful Alk in the effluent.
<Mmm; well; either have to switch out the media for something more soluble, or run much more flow through it>
When I tested it at 6.8 it was only 14. Reborn at 6.8 used to be 25. Maybe I got a bad batch of media?
<Am a fan of the friends, folks at CaribSea, but not their ARM product. I'd look around. B>
Re: Kalkwasser no PH impact      4/14/20

Thinking about giving SeaChem a try. Not a lot of reviews of the media but worth a try. Definitely a reputable company.
<A good choice, company. B>

Dosing Ca and KH       7/19/16
Thank you for taking this email.
I have a 110g reef tank of 3 months. Which is about my level of expertise, sorry. The tank has done well with many frags of coral, some fairly large.
A good number of inverts and a few fish. I use the Apex Dos system to do five 1g water changes per week. 2 days to get the replenishment tank filled and dialed in with salinity and temp. I currently dose Ca and KH manually every other day.
<Good. Am a fan of SeaChem's Fusion products, but Bob Starks, Sprung's copies C-Bal will do>
I maintain at the bottom of the spectrum...9/360. I am trying to work it up slowly,
<Also bueno>
I got behind do to ignorance. All other levels Ammonia,Nitrate,Nitrite, PH are 0. I average ph 8.3, temp 76, salinity 1.022-1.024.
<Mmm; I'd raise this to 1.025-6>
I may eventually buy another Dos, but in the meantime....could I dose up the levels of my replenishment tank(currently using Instant Ocean Reef Crystals which keep levels at 11/390) to the upper edges of the spectrum, say 12/420?
Given that depletion rate in the tank might bring it back to mid levels.
Sorry if this is a dumb question.
Ken Birgfeld
<Welcome. Bob Fenner>

2-part dosing schedule       1/26/16
I have been hand-dosing 25 ml of CaCl solution and 25 ml of soda ash solution (and also Kalkwasser in my ato water). This is keeping my calcium, alkalinity and Ph stable at good levels. I just bought a dosing pump to automate the 2-part dosing. I couldn't find much on-line as to WHEN I should dose except that it's good to dose alkalinity in the morning just before lights come on. So I programmed a dosing of alkalinity at 9, 10, and 11 a.m. of 8 or 9 ml; and the calcium I did 5 dosings spread evenly throughout the day (but not at same time as alkalinity) of 5 ml each. Is this fine? Is there a better schedule?
<Mmm; well; only testing during the times then will/can really tell. Likely this is fine, and I would def. pulse the material in during light/day time. More/less calcium is lost, taken up depending on factors such as lighting, the types and amount/biomass of biomineralizing life present, other foods...>
As always, thanks for the advice,
Terry Martin
<Thank you for sharing. Bob Fenner>

Cheap source of Sodium Carbonate    6/23/12
Hi Crew,<Evening Steve>
I'm back with (another) aquarium versus grille idea.    I just shared my idea for grilling spent activated carbon back to life.  I now want to share a great way to get cheap sodium carbonate.  I sometimes use sodium carbonate to adjust my pH up when my alkalinity is low (5% solution dripped in over a few days).
My cheap source is to take those old boxes of baking soda (sodium bicarbonate) from the freezer or refrigerator and dump them into a Corning ware Baking dish.  I might put them on my grille at 450oF for an hour or in my self-cleaning oven while I'm cleaning the oven.  The heat drives CO2 and water out of two of the bicarbonate molecules which convert to 1 molecule of (di)sodium carbonate [Na2CO3].  If you add a teaspoon of the baking soda to a glass of water and measure the pH it will be a bit low (6-7 if I recall).  If you take a teaspoon of the "baked" baking soda, the pH is > 10.  Nice!
So, instead of throwing out that old baking soda, bake it and use it in the tank.
Oh, so what happens to the "odors" that are trapped in the baking soda one might ask?  I don't know - - does this really even work.  My best guess is that they go through the same process a hot dog on the grille would go at 450oF for an hour.  It turns to carbon ash.  So, it is harmless.
Just some thoughts I hope you find worth sharing,
<Thank  you for sharing your experience.  You are creating what is called 'Soda Ash' which as you explain, is used as an Alkalinity supplement for tanks that have average to low PH ranges.  The Regular Sodium Bicarbonate can be used in tanks with a high range PH.  As you mention, it is creating by baking Baking Soda or can be bought in bulk commercially.  Again, thanks for sharing your experience>
Steve Ghera

baking the baking soda! HUH???? – 4/19/12
<Good Evening Pam, Bobby here>
I can't find the email I sent to you guys, but in it, I mentioned that someone  "bakes"  baking soda, BEFORE adding it to their tank, when using distilled water.     Did you get that?     I'm not an English major,.. but I do know that sentence really ran on!
Well, one of you guys wanted to know the reason for this practice and this is what he said;  
"You want to bake the baking soda to drive any moisture, and CO2 out of the baking soda so that it has an elevated pH when you use it. Without baking, it can actually drive pH down from the CO2 that is naturally attracted to it. " 
What do you think of that?
<Thanks Pam.  I am not sure to which prior email you are referring but the process you are describing is quite common and been a part of the hobby for quite a long time.  In addition to the two reasons you listed, baking it also makes it more soluble resulting in one gallon of this product having a higher concentration of bicarbonates.  To be specific, if you bake the soda you can get 1900 meq/L of Alkalinity in a gallon of solution versus 950 meq/L of alkalinity unbaked.  Thanks for your follow up and I hope I was able to shed a bit more light on this process><<Bicarb. to carbonate... B>>

Alkalinity (SeaChem products) and Zoanthid Behavior 12/21/11
<Hello Steve>
I have a 46 bow front with a 120w LED fixture. I am currently turning over my water about 50x an hour using 4 power heads and a HOB protein skimmer. I have about a 3" LSB and 50# of LR. I have 2 clowns, 1 Green Chromis, and 1 Damsel. My coral consists of a colony of Clove Polyps, 2 Orange Yumas, a colony of Branching torch coral, a colony of Branching Hammer coral, and a small zoo colony. I also have several hermits and snails as well as 2 Peppermint shrimp. I noticed several weeks ago that my zoos were not opening. I tested my water and here were the parameters I got. Sal 1.027, PH 8.4, Alk 4.5 dKH, Cal 460, Mag 1600, temp 80.2F. I used several test kits to confirm my reading and they were accurate. I brought the Alk up to 8 dKH over a couple days using Reef Builder. Then I let the tank settle a few days and did a 20% water change which leveled out the Mag to 1280 and my salinity went back to 1.024. The problem is that I cannot keep my Alk up. It keeps dropping to about 4-5 dKH over the course of a few days.
<Is not dangerous in a well maintained system.  Might want to get the calcium down to 400.>
Now my Mag is slowly increasing again.
I have not been dosing with anything except when I raised the Alk.
<Reef Builder does contain magnesium and likely the reason your Mag is going up.>
 I have not noticed any precipitation. The owner of the LFS was baffled and did not believe me when I told him what my parameters were. Do you have any idea what could be causing this and what I can do to solve it?
<I would use Reef Buffer for raising the alkalinity in your particular system.  Reef Buffer has a higher pK (8.6) and allows for greater pH stability in a reef system where the bioload can be significantly more than in a fish only system.>
 I have looked through your website but cannot find anything that helps.
<As to the Zoanthids not opening, it is likely due to your high (50X) turnover rate, they do not appreciate high water flow.>
Thanks in advance,
<You're welcome.  James (Salty Dog)>
Steven Edmiston

Is Borate In Alkalinity Boosters Harmful Long Term? -- 04/24/11
Most well regarded alkalinity boosters contain carbonate and bicarbonate, which makes sense in my limited understanding of water chemistry. But many of them also contain borate, which I believe is not native to sea water.
<<I'm certainly no chemist, Tim'¦but this statement is not exactly true. Most all known elements exist at some value in seawater. Borate compounds exist and are made up of such elements as Boric Acid, Boron, Sodium Borate (Borax), etc.>>
From my reading, borate acts as a pH buffer, so this is probably why it is included.
<<Mmm, indeed'¦ According to Randy Holmes-Farley (who 'is' a chemist), at a pH of 8, Borate provides about 'half of the buffering' even though it provides 'less than 3%' of the total Alkalinity>>
But if I regularly use one of these to maintain alkalinity, will the accumulation of borate be harmful?
<<Not likely with a quality supplement unless grossly overdosed (though the nature of these products would seem to limit this'¦re the 'marble analogy'). Borates do 'get used up' as a component of the calcification process and are also taken up by alga. The small concentrations utilized in quality Salt Mixes and Alkalinity Supplements should not be problematic. But do some reading and make your own conclusions. Here's a link to more information on Boron in seawater to get you started ( http://www.advancedaquarist.com/2002/12/chemistry ) >>   
Thanks, Tim
<<Happy to share'¦ EricR>>
Re: Is Borate In Alkalinity Boosters Harmful Long Term? -- 04/25/11

Eric --
<<Hey Tim>>
Thanks for that great link!
<<Quite welcome'¦Randy has put out some good info in past years, I really hated to see him drop from the aquarium scene>>
I suppose that because borate is such a common addition to alkalinity supplements, if it were seriously harmful to livestock we would be hearing a lot about it.
<<Mmm, maybe'¦ The problem is there is so much more anecdotal hobby information versus real tests/trials available'¦or at least, the former is more easily found (The BBs abound with such). A person really needs to 'look around' in their research and pull/evaluate info from more than one source (to include not making WWM their sole venue)>>
Still, it does concern me to be raising the level of an element a lot higher than it naturally occurs.
<<We are in agreement here'¦perhaps you should look in to 'simplifying' your Alkaline supplementation to pure Soda Ash (Sodium Carbonate) and/or Baking Soda (Sodium Bicarbonate). Be aware the former will raise pH quite sharply and requires extra caution re. While the Baking Soda is easily obtained at your local grocery store, I've not had much luck finding the Soda Ash (also known as washing soda) locally. But it can be purchased in bulk at a reasonable price on the Net, here ( http://www.bulkreefsupply.com ) >>
Thanks again!
<<Always welcome, mate'¦ Eric Russell>>
R2: Is Borate In Alkalinity Boosters Harmful Long Term? -- 04/26/11

>> pure Soda Ash (Sodium Carbonate) and/or Baking Soda (Sodium Bicarbonate) <<
Eric --
After a lot of searching I located a product made by Seachem (Reef Buffer) that raises pH and alkalinity without borate.
<<Ah yes'¦many good products from this company>>
It's probably just carbonate and bicarbonate, and I'm sure it's a lot more expensive than just buying the raw materials. But with the money I've thrown into this hobby, it's a small price to pay.
<<If you can afford it, you won't go wrong here with the Seachem offering>>
Thanks again!
<<A pleasure'¦ EricR>>

Water Parameter Help... the butler/buffer did it   1/24/11
Hey WWB crew,
<It's WWM and Hello Mike>
I have been struggling with strange water quality issues. My pH falls every 2 or so days to 7.8 from 8.2, My Alk swings from between 12-15 at random, and my calcium is at 600!?!? I am confused because I cant get out of the wicked cycle of adding buffer which throws my Alk up to bring my pH back then the pH falls anyways. My Mag is around 1200 which I think is normal.
<Very close.>
All I can think of that is causing this is my salt mix (Reef Crystals) and my source water (sink with Pur filter).
<The Reef Crystals wouldn't cause that.>
The sink water tests a low ph (7.8ish) and I don't add buffer to it, also its used in my auto top off water. Reef crystals adds extra calcium and Mag which I would guess can cause over levels of Calcium.
<Not to a 600ppm level.>
I do have sps and lps in my system and I have a 34 gallon tank which I do 2x 4% water change a week.
<It's not unusual to have small pH swings in small systems such as yours, not too worry here.>
All other parameters are fine (nitrite, nitrate, phos, ammonia). My corals and fish seem fine but I fear their health will fail if I don't stop or change whatever is going on. thanks for the help.
<Do not add any more calcium additives or buffers to the system. Your water changes will eventually lower your calcium level by way of dilution. A level of around 400ppm should be your target goal and once you achieve this, then maintain dKH at 7-10. May want to read here.
James (Salty Dog)>

Old Marine Buffer..Use or Discard? -- 06/14/10
Dear Crew,
<<Hiya Jillian>>
Thanks so much for your time!! You are appreciated!
<<We're pleased to be here>>
Just a quick question today.
I was given some Kent Superbuffer dKH from a friend. The product has not been used but I know that it is old- probably between 3 and 6 years. I wanted to use it to pre-buffer my RO water for my reef as well as for pH adjusting freshwater (to be used with Methylene Blue) for specimen dips. In your opinion, is this worth using or should I throw it out?
<<If it has remained dry/not caked up it should very likely still be effective (as far as Kent products go that is [grin]'¦much prefer Seachem myself), but it should be easy enough mix up a small batch and test it, I would think. Is worth a try'¦after all, it was free!>>
<<Happy to share! EricR>>

Maintaining dKH using buffers in ATO: Chasing numbers. SW Alk\pH\Ca balancing 8/6/2009
Hello Crew,
<Hi Mark.>
I'm jumping over here from the WWM Forum to maybe get an answer to my question and a potential solution. You have been tremendously helpful in the past and I appreciate the service you provide. I've read through much of the discussions on PH, alkalinity, and calcium at WWM and I believe I have a fairly good understanding of it.
<So you understand that as Ca rises, Alk will fall, and as a general rule of thumb, Mg should be 3x the Ca levels.>
However, after implementing what I thought would be a relatively easy way to keep my system alkalinity stable, I find myself with a small problem that I can't seem to figure out. I'm having a problem keeping my dKH stable without adding buffers to the tank. I want to be able to keep it buffered with the ATO water.
I measure my dKH regularly and I'm having trouble maintaining anything above 8 and it occasionally falls to 7 dKH.
<Which is fine actually.>
I can, with additives, get the dKH higher than 8, but it seems to want to fall back to 8 or less
even with massive amounts of buffer in the ATO water.
<So why keep fighting it?>
What is confusing to me is that I took readings this morning and my tank was at 7dKH. I
checked my premixed salt water and it's at 8dKH.
<No biological activity in the premix to bring it down.>
I checked my FW ATO tub and it's at 21dKH.
<Wow, How much are you buffering?.>
I use Sea Chem powdered products (Reef Buffer & Reef Builder) in my ATO water to buffer the tank, but I never really know how much to add or how high I need the dKH to be to keep the tank alkalinity up.
<A dKH of 6 - 12 is fine, provided it is stable.. Remember, stability is more important that a set number.>
I perform weekly 10 gallon water changes. I recently changed from Reef Crystals to SeaChem Reef Salt and that seems to be helping a small Cyano battle I've been wagering for the last year. I just couldn't completely knock the stuff out, so I changed salts to see if it helped.
It seems to be helping. The Cyano is retreating again, not that there was massive amounts of it....but it's ugly. The LR rock looks noticeable better too after only 4 weeks.
<A good sign. You don't mention what else is in the tank though..>
What I do not understand is how the dKH can be so high in the ATO water and it seems to be doing nothing to keep the tank dKH level from dropping.
<The buffers are being used\ 'burned' up or precipitating out of solution.>
My ATO uses about 1.5 gallons per day. This has been an ongoing issue since I set the system up. I'd be happy to keep the dKH stable at 8 or 9, but I don't seem to be able to do that without adding buffer directly to the tank occasionally. All of my RO/DI water is aerated for several days before use.
The only thought I've had is that I need to start buffering my premixed salt water to a higher dKH as well as the ATO water.
<A dKH of 8 is fine for premixed water.>
Readings taken last night:
PH: between 8.0 and 8.5 (hard to read between the scale)
<How much does it swing between lights on and lights off?>
dKH: 8 (added reef Builder in the morning, was dKH 7)
<If you don't add anything, what does it drop to?>
Calcium: 375 (time to add some Reef Complete)
<What is your calcium demand over a period of time?>
Magnesium: 1410
Phosphate: undetectable
Nitrate: 0
Tank: setup in April of 2008
90 gallon reef tank
30 gal DIY sump with integral refugium..7-8 gallon (Aragonite DSB and macro Algae)
1.5" drain
MAG 7 return pump
1/2" of sugar fine Aragonite substrate
<All fine. Do you use reverse lighting on your refugium?>
Aqua C EV-120 running on a MAG 5
50-60lbs of Live Rock
MAG 18 on Closed Loop for added circulation
(2) 150W 10K HQI's
(2) 55W Actinic
(1) 55W 10K Power Compact over refugium for macro growth
Support Eq:
Typhoon III 150 gallon per day RO/DI unit
15 gallon container with Buffered RO/DI water and Tunze ATO unit
29 Gallon tank for premixed salt water
<All good.>
<I think you are caught in a trap many of us get wrapped up in: Chasing numbers. The 'book' or specification states that dKH should be X and Ca should be Y so we add buffers and chemicals, and dose this and that and wind up chasing our tails.>
<What you need to do here is stop. Other than salt, and enough buffer in your top off water to get a pH of 8.2 - 8.4 and a dKH of about 7 - 8, stop adding chemicals to your system. Then, measure your dKH, pH and Ca both morning and night for a few days. record your readings. If your dKH drops below 6, add just enough buffer to bring it back. You should know what your calcium demand is, ad well as what your dKH wants to naturally rest at.. The key thing to realize is, if your Alk wants to stay at 7, let it.
Stability is much more important than chasing that perfect number.>
Thanks Again
<My pleasure, will also be posting this on the forum.>

Re: Maintaining dKH using buffers in ATO: Chasing numbers. SW Alk\pH\Ca balancing 8/7/2009
<<Hey Mark. Since we are quoting each other, my responses for this email will be in double brackets.>>
Thanks for the reply,
<<My Pleasure.>>
<So you understand that as Ca rises, Alk will fall, and as a general rule of thumb, Mg should be 3x the Ca levels.>
Yes, I understand that Calcium and Alk, are like a jar of marbles.
<<Hehehe, it is a surprisingly good analogy.>>
<So why keep fighting it?> Good question.....thought that my corals needed it to be in the 8 or 9 range.
<<Those are optimal numbers, but they will do fine at a lower number. You will need to keep a closer eye on your pH and the like.>>
<No biological activity in the premix to bring it down.> Understood.
<Wow, How much are you buffering?.> Obviously too much...was trying to use the ATO to provide buffer instead of adding it to the tank manually.
<<That is fine, just keep buffering to the desires level - 8 - 9 dKH.>>
<A dKH of 6 - 12 is fine, provided it is stable.. Remember, stability is more important that a set number.> I had no idea I could let it run at something like 6 or 7. Thought I needed it higher.
<<Lower dKH will enable you to run a bit more Ca in the system. Again, stability is the key.>>
<A good sign. You don't mention what else is in the tank though..>
Sail Fin Tang <<Will get way too big for a 90 gallon. It needs a big tank as they can get up to 16" in length. Also, they are big, messy eaters - which can drive down your dKH.>>
Coral beauty
(2) False Perculas
6 line Wrasse
Some hermits
1 Turbo Snail
Decent size Hammer Coral (growing well)
Small Zoanthid frags but growing
Green star polyps
Small Blastomussa Wellsi
Rose BTA
<The buffers are being used\ 'burned' up or precipitating out of solution.>
I haven't seen any signs of precipitation.
<If you don't add anything, what does it drop to?> Good question, I've never tried just letting the dKH go to see where it bottoms out. I didn't want to cause a problem in the tank.
<<Stop adding for a few days and see where it ends up. If it starts dropping below 6, buffer it back up.>
<What is your calcium demand over a period of time?> That's a tough question for me to answer. The real answer is...I don't know exactly.
Considering I do 10 gal water changes every week, I'm replenishing some lost calcium that way. I add calcium supplement about every 3 to 4 weeks when the calcium falls from 400 down to 375 or so.
<<Only way to tell reliably is measure every day for a week or so. That said, by your numbers, your demand does not seem to be very high.>>
<All fine. Do you use reverse lighting on your refugium?> Yes
<<OK, so we can rule out burn off from raised CO2.>>
I will take the advice to reduce the buffering in the ATO and see where the system settles in at. I never realized that I could let it run in the 6 or 7 range without harming something.
<<It requires a closer eye on pH and the like, but yes, you can run at 6 - 7.>>
As far as measuring the PH morning and evening goes, I'm not sure my test kit has enough resolution
to be able to determine a small PH swing. I will try it and see if I can tell the difference.
<<OK, one other suggestion, and you may or may not be able to easily implement it, is to add more aragonite substrate, this will provide a more natural buffering capability rather than having to keep adding buffers.>>
Thanks Mike,
<<Any time.>>

Re: Maintaining dKH using buffers in ATO: Chasing numbers. SW Alk\pH\Ca balancing 8/8/2009
<Hey Mark.>
I know about the Tang. Depending on who you ask, a 90 is either a minimum for a Sail Fin or way too small. It used to be in a 55. If I run across someone local, with a larger system to take him, I'll give him away.
Getting him out of the 90 won't be fun.
<A 90 is good for the first year or two, then they just get too big.>
Your suggestion about increasing the depth of the substrate is something that I've thought about. It could be done but....My decision to use such a small amount was intentional. I didn't like the looks of a DSB in the
display and it takes up so much room. I have also had much trouble in the past with BGA growing all over the substrate. So, I thought if I kept it to a minimum I wouldn't have as much trouble and I didn't want to get into that in between "no mans land" as far as depth is concerned. I also didn't want to go with a bare bottom tank. I have a DSB in the refugium, although it's not as large as the tank I should be getting some benefit
from it. I used the substrate from the system I upgraded from as a way to help cycle the tank initially. However, that substrate is probably in the neighborhood of 5 years old. I should probably start slowly switching that out for some sugar fine sand. Due to its age, its buffering capacity is probably gone.
<Likely so>
<You could use some sugar 'dead' aragonite sand. to eliminate the chance of importing any new BGA As far as looks are concerned, I understand. there are a few tricks you can use - If your tank is against the wall, you can add it to the back of the tank where it isn't as obvious. You can also add some to any caves or holes in your rock. Adding a bag of crushed coral somewhere in a flow of water will help as well.>
I measured my PH last night and this morning with no noticeable difference.
I would probably need to have a digital probe to see the difference.
<If you are doing a reverse light cycle, you may not have much a shift. By doing some tests, we can safely eliminate a pH swing as a cause for your alkalinity being burned up.>
I guess the good news is that the slight BGA problem I've been battling has all but been won. I've been frustrated with this junk for quite some time.
Could never knock it out completely.
<I'm one of the few that actually doesn't mind BGA as long as it is contained. I have one rock that it tends to grow on, but since it stays there and doesn't spread, I just leave it - it does do it's part in producing oxygen and soaking up nutrients.>
If I knew it would have been as easy as switching salt brands, I would have done it a year ago.
<In the process of changing myself, My usually brand that normally includes a free beach towel just has not been as good as it used to be.>
Thanks again for your suggestions, you've been a big help.
<Give me a shout here or on the forum.>

Alkalinity Boost, means, toxicity  -- 09/12/08 Good Afternoon, <Greg> I recently raised alkalinity in my tank from 7 to 10 dKH using sodium bicarbonate.? pH only increased from 8.3 to 8.4.? I dissolved about 1/2 teaspoon of sodium bicarbonate in about 1 cup of RO/DI water and poured slowly into tank near water flow.? Everything looks OK, except the Pocillipora coral.? Prior to this the polyps were all extended.? Now only about half are extended after 1 day.? Was the alkalinity raised too fast.? <Maybe... and possibly too much of the too-concentrated addition got poured on/too close to the Pocillopora... These additions should be done with/through new water during changes... that has been pre-mixed and stored for days time...> If so, is there a good chance the coral will adapt and open fully again?? <Yes> Lastly what is an acceptable rate to raise alkalinity? <A unit or so per week likely> Thanks, Greg <Bob Fenner>

Best time of day for adding buffer   5/2/08 Dear Crew.... <Sandra> Thank you for all of the wonderful information that the WWM Crew has provided over the years. I know if I ever have a question that I'll find the answer for it within those pages. This question has probably already been asked, but I have spent the last 3 days looking for it. And the words are starting to get blurry. I have a 28 Nano with low ph that I know is a CO2 problem that I am in the process of fixing. Question.....What is the best time of day to add buffer and can you add smaller amounts multiple times a day so that it doesn't swing the ph more than 0.2? <Toward "lights out" time in the evening is best> I test for Ammonia, Ph, Nitrite, Nitrate, Calcium, DKH, Phosphate, Iodine, Magnesium, Strontium, Iron and SG. All levels are within normal WWM's range. My ph at 6am is 7.85 and swings to 8.15 at 8pm, too low. Doing the indoor/outdoor test I found that it's a CO2 problem. I'm using the ESV 2-part. Using the minimum recommended dosage for my tank at 7am it raises the ph about 0.5-1.0, not good. Should I be adding it at the lowest point? <Mmm, no... at the beginning of it... night> Or can I add half in the morning and half at night to lessen the swing? I have more specific parameters if you need them. I know a lot of your emails get pretty long. Thank you so much for your time. Sincerely, Sandra D. <And, my usual bit here re real/longer-term fixes... IF you have room, interest... do consider adding a small refugium (with DSB, macroalgae...), tied-in with this little system... and run the lighting on it in reverse day-light pattern... Bob Fenner>

Re: Thank you, Bob Re: best time of day for adding buffer 5/2/08 Thank you so much for your reply, Bob. I will start adding it at night right before the lights go out. The 28 is kind of my "practice" tank as I am building a 240 with a refugium. <Ahh!> Your site is helping IMMENSELY with the build. Along with your books. I'm going to have the refugium on reverse light cycle. The little 28 is in my upstairs bedroom and gets very little air circulation. The 240 will be in a larger, more open environment with a lot of fresh air circulation. Just having the windows open all day yesterday helped a lot. My ph this morning at 6am was 7.97. I've never woken up to it that high. I'll be putting a small air pump and airstone on it today. And for long term, within 2 months, it will be used as my quarantine tank for the 240. <I see> Now if I can just convince my husband that reef keeping has changed dramatically from the old Delbeek/Sprung Reef Aquarium days of not feeding corals and no substrates and temps above 77 are deadly, I'll be all set. Thank you again. I look forward to hearing you speak in Atlanta in September. You and your crew are heroes to little corals and fishes all over the world. Sincerely, Sandra D. Vacaville, CA <Thank you. BobF>

Alkalinity Buffers 10/20/07 Crew, <Hi Scott> Can sodium bicarbonate be substituted for Sea-Chem's alkalinity buffer? They say that it is bi-carb based. <It can be, but I much prefer using Sea Chem Buffer as it is a blended product and not just carbonates. James (Salty Dog)> Scott

Re: Alkalinity Buffers 10/20/07 Hi James, <Hello Scotty> Thank you for the fast response. <You're welcome.> Along the same line of thought, I have read much on the topic of pH and buffering, and it has been written that in addition to testing pH and alkalinity, that one should also test acidity. My question is where do I find an acidity test kit I have tried several online stores and have even Googled the subject and cannot find an acidity test kit anywhere. All I can find is that most companies refer to pH as a measure of acidity. <pH is a measure of both acidity and alkalinity with pH 7.0 being neutral. Readings under 7.0 are considered acidic and readings over 7.0 are alkaline.> Confused, <Not any more, but do read here. http://www.wetwebmedia.com/marphalk.htm James (Salty Dog)> Scott

Re: Alkalinity Buffers 10/21/07 James, <Scott, and sorry for the Scotty.> Dare I correct you? 1) pH is NOT a measure of acidity and alkalinity, it is a measure of hydrogen ion concentration. <I realize that, just trying to explain in a easy to absorb format.> 2) Acidity is a measure of resistance (buffering capacity) to an upward change in pH, and 3) Alkalinity is a measure resistance (also buffering capacity) to a downward change in pH. 4) A /low pH reading is acidic, but not acidity, and 5) A high pH reading is alkaline, but not alkalinity. Read the link you referred me to if you are confused. Bob knows what he is talking about. <Yes, he does, which is why I referred you to the link.> 6) My name is Scott, not Scotty. <Again, sorry.> All I wanted to know is WHERE to find an acidity test kit and I finally found one at http://www.aquariumcity.net/Instruments/HI3813AlkAcid.htm <I've been in this hobby for 30+ years and have never heard of anyone wanting or using an acidity/alkalinity test kit. In my opinion, the standard pH and alkalinity test kits (of good quality) provide all the information that is necessary for my needs. James (Salty Dog)> Scott

Buffers and Caribbean/Florida Live Rock 10/3/07 Hi Crew, Thanks for taking my e-mail today! <Been a few days now I think. Sorry about that...> I have a question about using buffers in my reef system. I am currently using Seachem Reef Buffer (pH Buffer) to supplement my top off water. I also have their reef Builder (non-pH buffer) but I haven't really been using it. I add enough Reef Buffer routinely to keep my alkalinity above 3meq/L. I have heard that people dislike using pH buffers. I assume this is because the addition of too much at once could drive up the pH resulting in calcium carbonate precipitation. My pH is usually around 8.2 during the day. The reason I use pH buffer in my top-off water in the first place is because I do not like adding low-pH top-off water to my system. <Have you thought about using Kalkwasser? Calcium hydroxide is great because it can raise your pH, your alkalinity and your calcium all at once. It might also help with phosphates as well as some other possible such fringe benefits.> I notice less of an impact on my SPS corals (polyps closing) when using pH buffer. Since my pH is 8.2 would the best course of action be this? : add enough pH buffer to top-off water to reach a pH of 8.2 (same as system) and then use non-pH buffer for the rest of my alkalinity supplementation via top-off water. If I continue to use pH buffer exclusively, then would it be best to limit the amount of pH buffered top-off water I add to my system so that the pH climbs no more than .2 points (ie 8.2 to 8.4, similar to how Anthony Calfo doses Kalkwasser)? Also, if I see no rise in my pH over time with use of pH buffer, then is there any problem/disadvantage using pH buffer that I am not seeing? <I think you're thinking a little too hard about this. pH naturally rises and falls throughout the course of a day (up to even .4 variation is pretty normal). Anthony Calfo probably likes Kalkwasser for the same reasons I do (see above). If ever the Kalk should fail you in calcium or alkalinity, you can simply use baking soda and/or calcium chloride to adjust accordingly. For details on that, please see here: www.asira.org/practicalchemistrybasics> My other question is in regard to Atlantic Live Rock. I want to create a Ricordea biotope in the near future. Even if they don't come from the same depths/environments I want to at least keep Western Atlantic Fish/Inverts. I was thinking about putting Live Rock from Western Atlantic in there as well but I have heard quite a few drawbacks with that rock. I have heard that it often has bristleworms and Aiptasia. <Bristleworms are good things. Aiptasia not so much, but they can be managed with quarantine.> I have also heard that the rock is very dense. Would it be best to just skip this part of the biotope and use Pacific Rock? <Well, technically, if you use Pacific rock, you don't really have a "biotope" anymore. But otherwise, I don't think it makes too much a difference. The Ricordea should do fine with either.> I have liked it in all my other systems. Sorry for the long e-mail and thanks again for taking the time to answer my questions! Thank You, Tim <De nada, Sara M.>

Falling Out Of Solution? (Powdery Stuff In Prepared Water) Hello Crew, <Hi there! Scott F. with you today!> I submitted this question almost a week ago and had no response, so I am trying again. <Yikes! Sorry your query fell through the cracks...Happens now and then, unfortunately.> Twice now I have added 1 tsp. of Sea Chem Reef Builder to my 10 gallon tank of "Water Change Water" after I aerated and added salt. After a day the tank gets cloudy with a fine white powder. The fresh water consists of RO and I use Coralife Salt, I added nothing else.  Is this a "snowstorm" I have read about? I tested the Alkalinity at 4.5 meq/L after this happened. Can temperature change affect this? The tank went from 77 to 84 degrees during the day and when it got warm, I noticed the powder. Thanks for your time. Michael <Interesting thought, Michael- but I don't think that Reef builder would cause the "snowstorm" effect at this dosage. The cloudiness is apparently something in the buffer falling out of solution. Water can only hold so many dissolved substances. I have noticed this sort of phenomenon myself when using buffer products, and the water has cleared after a day or two. If the water tests okay, I would not be overly concerned about it. Sorry I could not give you a more specific answer, but it seems like it may not something that is very detrimental. Regards, Scott F.> Buffer supplements Hey Guys. I have a quick question about the old no matter how much can you add, nothing happens. After reading much in the archives, (still reading) I am going with old dilution solution. My question is should I stop all additions (buffers, Kalk, calcium Marin plus) until things are back in balance. <Water changes will help...I think. You don't state what's out of balance so I gotta guess that you mean alkalinity and calcium> I'm still trying to perfect treating my RO water and think adding buffers too soon (before aeration) or to much may have been the beginning of the problem. <Test the RO before adding anything. Then I aerate over night, then buffer over night, then add salt...and test levels again. Do all of this testing on a couple of batches of water and then you can test less frequently. Find out what the "normal" raw levels are for your RO and then add the appropriate amounts of supplements to bring it up to where it needs to be> Before I just added tons of buffer and calcium to the tank to keep balanced and Kalk made with untreated ro water. <The word "tons" may be your problem. Please test regularly for anything that you are adding> Anyway, thanks for all of your time. <You're more than welcome. Keep reading and learning! David Dowless>                                                                              Mark

- Adding Buffers - Jason, <Good morning.> I do let my water sit up to a min. of a week, but the buffer directions say a tsp per 20 -30 gal & I add 3 tsps for 25 gal. to hit 2.5 alk, Is this normal?, or bad for my tank? <I would say bad... buffer capacity in freshwater will be different than salt - I would add one teaspoon as recommended, wait 24 hours or so, and then add the water to the tank and measure the alkalinity there...> If my ph is at 8.4 & the alk is @ 1.0 do I still continue to add buffer to get a 2.5 alk reading? <I wouldn't> I believe my ph seems to continue to increase. <You are adding too much buffer. Ask yourself this question - what is it that I am keeping that requires increased alkalinity. If you are just trying to meet a number, then you're doing it for the wrong reason.> Thanks J, Darrin <Cheers, J -- >

Diatom Algae, Light, Buffers I should then be doing bi-weekly changes of at least 10% each time? Should I be gradually increasing my lights up to 12 hrs per day or wait till my situation is under control and I get inverts/coral? <I would crank it now and burn the algae bloom out by it outgrowing the nutrient supply. It may actually increase as this algae usually shows up in light and goes in dark.> I was thinking of going with actinics only for first 2 hours, then actinics and 1 MH for the next 2 hrs, then the actinics and both MH for the next 4 hrs, then actinics and 1 MH for 2 hrs and finally actinics for the last 2 hrs. Does this make any sense? <Not really, the actinic only is for viewing more than the benefit of any inhabitants.> Also the baking soda is recommended on your site over buffers by Bob Fenner. Should I drop the soda and buffer my RO replenishment water with a quality buffer? Thanks <Uh, for buffering FW for dips maybe, but not for buffering marine systems *alone*.  For instance, the buffer I use contains far more than Sodium bicarbonate; Sodium, magnesium, calcium, strontium and potassium salts of carbonate, bicarbonate, chloride, sulfate, and borate for instance. This causes ionic unbalance over time. Also, good buffers include dosing directions for a known result.  I recommend and use Seachem buffer for RO make-up and supplementing new water and regular carbonate/alkalinity use.  Hope this helps! Craig>

Alkalinity Hi Bryan, PF with you tonight> Hello everyone, I have a quick question again about ALK, but more on the lines of RO/DI water.  I am starting up my tank again (75 gallon).  I have been making up my water this way.  I have a Rubbermaid trash can that I fill with 20 gallons of RO/DI water, I aerate and heat for a day, add buffer and aerate then add salt and continue to aerate for at least a day.  Top off water is same as above (w/o salt of course)....here lies my problem.  When I buffer I have been adding Seachem reef builder to set Alkalinity. The other day I decided to test the make up water for ALK b/f I added salt.  I am using Salifert test kits. The dKH after buffer and b/f salt was at "7" and pH 8.3 at 78degrees.  I then added salt (tropic marine) let aerate for 24 hours and retested.  The dKH was 13.8 (WOW) can you explain this huge jump... <Wow is right, I do know that most salt mixes (such as yours from the ingredients list) have additives to buffer the water. I would assume that spikes the levels up.> I know that the salt mix contains carbonates and bicarbs but I didn't think there would be that much difference. (I tested 2 more times and still 13.8dkh)  Here is problem...How do I buffer the RO water? <Well, since you're not adding the salt mix to the top off, I don't think it would be a problem. Have you tested the water in the tank?> I have thought about buying the products made for adding minerals back to RO water.  What do you think? <I'd say give it a try, and see what you get results wise, but first I'd test your tank water. If the dKH is ok, I wouldn't worry about it.>   Thanks again Bryan <Your welcome, have a good night, PF>

Sodium Bicarbonate and Carbonate 6/11/03 Hello, I've done a search on your site but could not find the answer to this. I am currently using baking soda (sodium bicarbonate) to buffer my water changes and top-off water. I've read that long term use of this may be detrimental (not sure "how" detrimental, though). <hmmm... I know of no deleterious "accumulated" effects. Simply avoid spiking water quality with excessive use in a short period of time. Quite a safe product overall> I've also read of people using a combination of baking soda and washing soda (sodium carbonate) for alk/ph buffer additive. I've read on commercial buffers that these are the two main ingredients. <correct> Can I use this combination for long term use instead of the commercial products or just keep using the baking soda alone? <certainly... just let your test kits be your guide (ALK, pH)> I really like the results of using sodium bicarbonate (baking soda) and its inexpensiveness, compared to commercial products. I've been using it solely since late December; my alk maintains between 3.5-4.25. If using bi-carbonate AND carbonate would be better, what proportions or "recipe" would be recommended? I've been using Mr. Fenner's recommendation (from his book) based on 1 tsp. of baking soda for every 20 gallons of tank water. Thank you. <I've seen several recipes on the net... as well as in the past works of Moe, Spotte, et al. Frankly... I don't think you even need to add the washing soda. With satisfactory ALK... I cannot see/say the advantage to modifying the bicarb routine. BTW and FWIW... I buy and use the commercial mixes  <G>. I really like the variations/options in the Seachem line. Kindly, Anthony>

Raising alkalinity Hi, Is this a good practice? I put one and half teaspoon of Kent SuperBuffer in a liter container full of fresh water and add it to my 50 gallons tank drop by drop. This quantity of buffer rise my alkalinity by approximately .2 meq/L (I use SeaChem alkalinity test). I do this when the light is on. thank you PS. sorry for my English, I'm French Canadian. <No worries about the English. I would test the alkalinity in your tank. If you don't need to bring up the alkalinity more than where it is now, then I would stop adding the buffer compounds. Cheers, J -- >

- Buffering Saltwater - Hi gang: I'm seeing real growth/improvement on all life forms in my tank after getting a look at REEF INVERTEBRATES and adding a refugium to my system. I remember reading (can't remember if it was in the FAQ or the book) that I should buffer salt water once it's mixed up and before it's added to the tank. <Depends on the origin of the water - if mixed from RO/DI or otherwise purified water, you should add buffers before you add the salt. If using natural seawater, then buffers should be added while the water is being cured.> Sounds like a great idea. . . do you have a rough formula for the right amount of buffer to add for a 20 gallon batch? <Not really... depends on the buffer being added. Would just use an alkalinity test kit to test before/after additions to get a handle on it.> And will adding the buffer influence the salinity reading on my refractometer in any significant way? <No.> I generally use baking soda for my buffer. . . Kent Turbo-calcium for the calcium. . . plus a Sea Lab block in the sump. . . although the block isn't eroding much anymore with the addition of the 'supplemental' buffer and calcium plus addition of an aragonite DSB in the refugium. I used to run with my calcium readings on the high end. . . buffer on the low. Since addition of the DSB, it's more like the reverse. . . and I'm careful on the calcium to avoid the dreaded 'snowstorm' effect I keep hearing/reading about. As always, thanks for your help on this.  Chuck <Cheers, J -- >

Buffer Question <2/1/04) Hi Bob, <Steve Allen covering tonight.> I was wondering about the use of "buffer" additives to the RO water used to replace evaporation from my reef tank. Currently I do not add any buffer materials, but I am considering whether it would be wise to do so. My understanding is evaporation with remove 'n' number of H2O molecules (i.e., pure water evaporates); thus we have lost 2'n' hydrogen atoms. Therefore the top-up water needed to replace this should also be 2n hydrogen atoms, to ensure the effect on System pH is identical. Is my understanding correct? <Merely incomplete. You are not considering the factors that affect free H+ ions. True, pH measures these, but it is buffer that keeps them bound up so the pH stays alkaline in seawater. Otherwise, the tendency is to head to neutral (7.4), or even lower due to organic acids in animal waste. By performing RO on your tapwater, you have removed all of it's buffer capacity. Marine tanks naturally lose buffering capacity (carbonate hardness) over time, requiring replacement. There's a lot of good info available on this subject both at WWM and other web sources such as Advanced Aquarist Online.> If so, does this suggest top-up water should not contain buffer additives? <no> Or is it the case that marine tank pH tends to drift downwards due to the bio-load <yes>, and we are simply using the top-up water as a convenient mechanism to replace hydrogen lost due to the filtration of the System? <Not hydrogen lost. Buffer capacity to keep the H+ ions bound up and maintain the alkaline pH we need.> The reason I ask this question is that my reef tank starts the day at pH7.9 and ends at 8.1. <A reef ought to be kept higher. At or around 8.2 to 8.3 would be better. It would be nice to not have the pH drop below 8.0-8.1. I monitor mine electronically, and it never goes less that 8.1 or higher than 8.3> I am starting to benefit from a newly established reverse lit refugium with a DSB - hopefully my pH will continue to improve as the refugium matures. <Yes, this can help stabilize pH if you have macroalgae in it.> Besides weekly 8% water changes the only "additive" to my system is a calcium reactor. <Also great for replacing buffer.> I try to do without additives as they can prove costly over time, mistakes can be made with application (we are all only human!) and leaving the System to go on holiday becomes a larger burden for the person who looks after the tank. <For those who can afford the initial investment, this is a great way to go. Anthony is big on Kalkwasser. I use the 2-part buffer/calcium from B-Ionic, but the cost of that adds up over time. Someday I'll figure out where to fit a calcium reactor in my system.> If adding a buffer to top-up is the "done thing" in the industry then I will follow suit, but reading through the WWM pages left me uncertain if there was consensus in this area. <No absolute consensus out there.> What is your take on this subject? <IMO, the bottom line here is that you are replenishing the buffer in the tank with your calcium reactor. The reason to buffer your RO water is to replenish its own buffering capacity that was removed by the RO process. I have been very satisfied simply adding the recommended per-gallon dose to my RO water only when making new salt water for water changes. My water is so hard here that I do not seem to need to add buffer to my top-off RO (no DI), which has a pH of 8.8. I'd suggest you check the pH of your top-off. If it is in the pH range you need, then you don't need to buffer it.> As always, thank you very much for your advice. Andrew Senior <Hope this helps. I do not profess to be a chemist. Do read more if you desire a deeper understanding. Here's a start: http://advancedaquarist.com/issues/may2002/chem.htm >

Buffers WWM Guys, I am topping off and doing changes with RO water. Also, I use B-Ionic two-part mix for calcium supplementation and Instant Ocean to keep SG at 1.025, pH is 8.4. How would you recommend I buffer my RO water? I tried using baking soda and it precipitated out when I added Instant Ocean. Why did this occur? <You added too much buffer. The salt mix has buffering compounds, too, and with what you put in first, the pH got too high and drove the calcium to precipitate out of solution. I prefer to buffer my water after adding the salt. I aerate and heat the water first for a day. The add the salt mix and mix for another day. Lastly, I test the salt water for salinity, pH, and alkalinity and buffer according to the results of my tests. If you wish to buffer before adding the salt, only add enough buffering compounds to bring your raw RO water to a neutral pH.> I am interested in raising my calcium to 450 from 350 ppm. I have good coralline growth and tolerable slow growth in my SPS/LPS corals. Perhaps I could cut back on the Bionic I use if I buffered my water? <Perhaps, on use a calcium reactor to really accelerate growth. That is, if you have a large enough tank. I would find it hard to justify the expense if you told me you had a 29 gallon mini-reef. If 75 gallons or more, the money you save on supplements will outweigh the initial cost in a few years.> What should I use for this? <I think Seachem products, Marine Buffer and Reef Builder, but there are other fine products. Aquarium Systems SeaBuffer is also nice. -Steven Pro>

pH alk? I have a few questions on pH and alk. I've seen in different books that dKH should be between 7-10 and also 12-18. which is correct?  <8-12 dKH is safe and healthy IMO. Closer to 8 if you run a high calcium level (over 425ppm). ALK over 12 dKH is dangerous (crystalline precip) and only recommended for hardcore coral growers that test water daily and have many scleractinians. Most people will have problems with such a high ALK in time> my problem is... my dKH is 16-17. my calcium is low, like around 300.  <typical... neither can easily or safely be at the high/max end. Still... the tank would be better off around 10dKH and 400ppm> my pH is around 8.0-8.2, but will drop without the addition of SeaChem marine buffer to 7.8ish within 48 hours.  <a lack of aeration (not circulation) may be indicated here (accumulated CO2). Aerate a glass of aquarium water vigorously with an airstone and see if the pH rises after 12 hours. If so... you have a CO2/aeration problem.> how can I raise the pH without increasing the alk? <Kalkwasser> my alk is so high right now that I can't seem to increase the calcium without clouding my tank.  <exactly... a crystalline precip. Do several large water changes to dilute this imbalance then add Kalk and buffer as necessary> also, why would the pH drop like that if the alk is high?  <many reasons... CO2 being one of them> I have a 50g breeder w/ 50lbs LR, and few snails and hermits and some polyps. no fish yet and I'm not feeding anything. 20g sump w/ skimmer that needs to be emptied every 3rd day. all other readings are where they should be. thanks, Neil <best regards, Anthony>

Alk/phosphate questions Mr. Fenner, <Hi Mike, Craig here today> I have a few more questions, I just tested the alk today (have been testing daily waiting for it to fall from high levels) and the reading was 4meq/L dKH was 11.2.  <This is good. Ideal range is 3.5 to 5 meq/L.> Up until now I suspended topping off the tank with Kalk, because of the previously high level. Is now a good time to top off with Kalk water?  <Kalk is a calcium supplement and does not directly affect alkalinity, but does optimize the system alk. It does have an extremely high pH (12) so should be administered at night to moderate pH fluctuations and dosed according to daily average usage of calcium. See Kalk faq's at: http://www.wetwebmedia.com/kalkh2ofaqs.htm >  Secondly, I suspended adding a buffer to my new water for the water changes, can I add the buffer too? The Ph was at 8.1 tonight. Will the buffer raise the alk drastically or more like maintain it as it does the Ph? <If using RO/DI water, aerate 12-24 hrs, test pH and buffer to 8.3 I use Seachem Marine Buffer and follow the dosage on the label. Add salt mix, run powerhead/aeration/heater for 12-24 hours. Should be 8.3-8.4 pH. PLEASE do figure average alkalinity usage as you do for calcium and dose the buffer/carbonate additives to maintain 3.5 to 5 meq/L alk.>  ---------------------------------------------------- The reason I ask the buffer question is this, I also have an algae problem, its brownish and covering over half the glass in the tank, and some spots of red algae. From an email I got here I heard a higher Ph level will help combat the high phosphate level (0.25ppm). <Kalk use will take care of this. Test calcium and dose Kalk daily to match usage. This is likely not phosphates, but diatom algae and Cyanobacteria. Increase circulation for Cyano and reduce nitrates and silicates for diatom algae. Lowering phosphates will naturally help. If this is a newer tank, this is a stage your tank will go through. Check your source water, make sure your skimmer and filtration is optimized, and remove as much as possible.> Here are the steps I'm thinking of taking: reduce the period of lighting from 12 hrs to 8hrs. <VERY bad idea if you have photosynthetic inhabitants you want to live. They need 12 hours. Will not reduce phosphates, silicates or nitrates.>  Adding the buffer to raise Ph. <Also bad idea. Add buffer to alkalinity test results. All else remaining normal this should provide a 8.3-8.4 pH. Adding buffer indiscriminately will raise alkalinity to abnormal levels.> Buying a chemical phosphate reducer. <Some of these are quite good. I like Polyfilters.>  Will any if not all of these help reduce the phosphate in the tank? <Kalk use, water changes with phosphate free source water, low phosphate foods, appropriate feeding, skimming, filtration, PolyFilter/chemical will all contribute.> Tank Parameters: amm 0 nitrite 0 nitrate 7-10 alk 4.0 meq/L (down from 5.5 yesterday, is this normal to drop this much overnight) <With calcium additives, yes. Test both alk and calcium on alternate days adding supplements for calcium and alk on alternate days until ideal range for each is attained. Test, write down results, stop additives for three days, test again, subtract and divide result by three. That is your daily usage of calcium (Kalk) and alkalinity (buffer). That's what you have to add of *each*, every day. Kalk at night.> dKH 11.2 Phosphate 0.25ppm Calcium 365ppm (up from yesterday's 330ppm, using reef evolution concentrate) <Yes, will drive alk down more so test alk and calcium while supplementing calcium.> Ph 8.1 <Likely AM test? Test in PM> SG 1.025 Temp 78F Lighting 12h/day Thanks once again, I really need to buy your book, Mike <Hope this helps Mike! Craig>

Re: alk/phosphate questions Mr. Fenner and Company, It's Mike again, a few more questions.  <Hi Mike> Today I tested the Calcium and it was a 335ppm, down from 365ppm yesterday...does this seem likely or just an erroneous test yesterday?  <Yep. That's likely your calcium use for one day. Clams, SPS, LPS, etc use more calcium and adding alk will use some as well.> And one more algae question. You guys suggested I have diatom algae present in my tank, I scrapped the glass off and it looks clear, hasn't grown back by the barrel full yet.  <Yep, likely diatom algae> Now today I noticed some small green hair-like algae growing on my live rock, so I asked another friend of mine into reef tanks, he said get rid of it quick...it will take over a tank fast! Is this true and cause for concern?  <Yes, it can and will spread if you don't pick and pull it now. some Tangs eat it, but usually only when short. Best to do away with it before it gets going.> I have some margarita snails (3), some Cerith (3), and some scarlet reef hermits (10), and Nassarius snails (15). Will any of these aid in the control of this? And what type of algae could this be? <Not usually. This is green hair algae of course! Look up algae and specific ally green-hair algae on WetWebMedia.com for other possible controls.> After reading your reply below, I'm going to start topping off with Kalk water, and that Ph reading (8.1) was taken at around 7:30pm here that's why I wanted to dose Kalk to maybe raise it without the buffer. and if I understand you, Kalk doesn't effect alk reading? then I shouldn't have suspended it as I did. Thanks once again, Mike <Right. It reduced your calcium and didn't do anything to your alk. You can add buffer/carbonate up to 5 meq/l alkalinity, (which will likely produce an 8.3 pH), but using Kalkwasser will help with keeping the pH up as well. Make sure you test your alk regularly and also magnesium with Kalk use as it will be depleted over time with Kalk. Hope this helps, Craig> 

Baking Soda Hello, I had written you yesterday about some alkalinity problems, and you had suggested the use of baking soda. I was wondering if this is just a quick fix, or whether you can replace marine buffer with the baking soda on a weekly basis. I wasn't sure if baking soda also has a direct impact on Ph levels. Currently I am only using marine buffer. Although in the past I have supplemented with SeaChem's Reef Builder. I didn't know whether I could continue to use Marine Buffer and supplement that with baking soda, or use baking soda for a quick fix and then start adding reef builder again. Thank You  Matt Smith  >> A very large part of "marine buffers" is... um, simply baking soda... so, yes, this material can be used in the long term. By itself, sodium bicarbonate will not elevate pH much beyond 7.8... All the stated products are miscible. Bob Fenner 

Alkalinity Dear Sir, I have a 4-weeks old set-up live rock tank. Before I set up this L/R tank, I had sent four days to go through your articles. They are great and useful. <Thank you my friend.> Recently, I have got the following information. Light - Power Compact 2 Watt/Gallon Ammonia, Nitrite, Nitrate - Close to zero Salinity - 1.0225 PH - 8.3 Alkalinity - 8 dKH Calcium - 450 ppm For growing coralline algae, do you think I should raise the alkalinity to 10 dKH, 11 dKH or 12dKH? <This would be better... but might well "cost" you in lost biomineral... see you mention your means of supplementing below> Currently I am using Coralife Calcium Supplement to raise/maintain Calcium level. If you suggest me to raise alkalinity, what brand do you think is safe and can use in junction with Coralife Calcium Supplement? <Mmm, would actually leave your levels as they are now... If was raising, would seek out the same companies products... And in the longer term possibly employ a calcium reactor for pH, alkalinity, biomineral content...> Because I know Coralife Calcium is a good product and safe to use. Thanks, Joan <Be chatting. Bob Fenner>

Alkalinity Dear Sir, For most cases, I know that it is better to buy a Calcium Reactor for balancing both calcium and alkalinity. But my tank is way too small, only 23 Gallon... <Mmm, likely so> In my case for growing coralline algae, is my calcium level at 450 ppm imbalanced with a alkalinity of 8 dKH? <No.> What is the best combination reading for calcium and alkalinity? <400-450 ppm, 10-12 dKH... but other factors are as important... like magnesium concentration... good to develop an "overall perspective" and understanding here> What brand name of alkalinity buffering you think is the safest one and can in use with Coralife Calcium supplement? <Coralife, SeaChem, Kent, Tropic Marin, Salifert, Knop... similar in composition...> What do you think about Seachem's Reef Builder? <A good product. Bob Fenner> Thanks, Joan

Low dKH Bob: I just finished reading most all the Q & A's on alkalinity, pH and calcium and now clearly understand why I never became a chemist. <Really? Have endeavored to keep all at minimum, simple terms... and the concepts, formulas are actually quite simple... taken a step at a time...> But I see how these must work in harmony together much like barley malts, hops and yeast.  <Good... and tasty comparison> My dKH is constantly low. I add Kalkwasser which I now understand lowers the dKH. With a lower dKH the pH was also dropping which in combination I suspect contributed to my problem of my coralline algae bleaching.  <Yes! You're "getting it"> I was under the misunderstanding that adding Kalkwasser took care of everything.  <No... "it's" just calcium hydroxide... actually drops out carbonates, bicarbonates, even other alkaline earth minerals (e.g. Strontium, Magnesium)... and the hydroxyl radicals... let's not get started on these today> I use RO water to top off, about a gal a day, which I have not been adding anything to. Because the pH of the RO is very low would this constant addition on a daily basis bring the total pH of the tank down and the constant addition of the Kalkwasser on a daily basis bring down the dKH thereby further affecting the pH?  <Mmm, well "doesn't bring down low", but by not adding alkaline reserve... doesn't boost buffering, raising of pH... "fighting" the reductive (acidic) influences in a captive system...> And the simple question......should I be adding sodium bicarbonate to the top off water? <Yes, a good idea... at least this... if not a more complete "buffering, pH boosting" medium/prep.> My strategy is to slowly increase the dKH by adding a buffer and KH builder until I reach around 10 dKH. Keep adding the Kalkwasser to keep the calcium around 400, and add sodium bicarbonate to the top off water each day to maintain the constant dKH. Does this sound like a reasonable lay persons explanation and plan of attack, or has the combination of barley malts, hops and yeast thoroughly lowered the entire chemistry of my brain? <Hah! Well mine too if this is the case... Your plan sounds good, workable. I would proceed immediately. Bob Fenner> Thanks for any help Jim

pH and Alkalinity balance Hi Bob. Thanks for being so approachable and one of the most knowledgeable aquarists in the business. <You would do the same, given a similar background, circumstances> I have a puzzling question...I have a 180 gallon reef tank. The problem seems to be keeping the alkalinity up above 6. Whenever I add buffer to get the alkalinity up, the pH seems to go up over 8.6. If I add buffer I can get it up to 9-12, but then the pH seems to keep rising. Even as the alkalinity falls, the pH stays up around 8.4 or 8.5. Is this necessarily a problem? <Mmm, no... considering that you don't have nutrient concentration problems (like high, detectable ammonia)...> Any advice you could give me on this situation would be greatly appreciated. <There is much to be elucidated here re the interaction of principal chemicals (mainly carbonates, bicarbonates and biominerals, i.e. Calcium, Magnesium, Strontium...), supplements, adjuncts, gear that affects same... and resultant pH... Suffice it to state here, that you are likely adding the "co-factor" in the way of a chemical preparation that is resulting in this anomaly... you could counter the effect by adding carbon dioxide... a possibility... or switch to a calcium reactor to keep all factors stable and "about right"... or elect to "do nothing" which will likely be fine. Please avail yourself of the information on the site WetWebMedia.com re these issues, and if you'd like, supply input about your supplement practices, set-up... and we'll work into specifics. Bob Fenner> Thanks and keep up the good work! Joe

Re: Specifics on ph-alk question Hello again Bob, Thanks for the reply to my original question concerning ph-dKH balance. You said to get back to you with specifics, so here goes. 180 gal. reef/ 3+inches live sand/150lbs.? live rock/40some asst. pieces coral/ 8 fish [largest are a yellow & purple tang]./asst. stars&snails, etc. Equipment-4 160 watt VHO bulbs powered by icecap ballasts/ photoperiod: actinics 11am-10pm/50-50s 12pm-9pm/Berlin skimmer w/Rio 2700pump/ U.S. aquar. wet-dry w/Iwaki pump-1300 gph return. I do a 45gal. water change every 3 weeks. I use R.O.-D.I. water for water changes/make-up water. As for additives, about all I add is Kent turbo calcium [1tsp. per day] to try and keep the Ca level up, and SeaBuffer as needed for alkalinity. I manage to keep the Ca level about 360. Every now and then I'll add iodine, strontium, or magnesium if the corals look as if they need something, but this is rare, as most of the time they look great. On any given day the ph will start out at 7.9-8.0 and rise to about 8.4-8.5, even though at times the alkalinity will drop to 4 or5. I would like to keep it up around 9 or 10, but as i said , as I add buffer it wants to push the ph up over 8.7. Nothing seems to be adversely affected, but it is really puzzling me. I really appreciate your taking your time to think this over and hopefully come with an an answer. Thanks a million, and keep up the great work. <Will try/endeavor to do so. What you have is a semi-classical case of "yo-yo'ing" of adding simple, soluble sources of alkaline and co-precipitating calcium (et al. alkaline earth elements/compounds... the Mg and Sr) additives... If you saw the energetics of the supplementing and the money being turned into white sediment "cement" in your system you might scream. Do consider either "going with" a simple two part (like B-ionic) alkalinity/biomineral treatment scheme BY ONE MAKER (wow, that's bright), or making the light year jump to a calcium reactor here. "IT" is your supplement practices that are (self)defeating you here. Please read over the Marine Alkalinity, Calcium et al. related sections on our site: www.WetWebMedia.com for more peoples anecdotes, explanation of what is going on here. Bob Fenner> Joe

Buffering/lighting Hi Bob, My tap water does not have a lot of buffering capability. <Do you need, want more? Can be augmented easily> When I do my regular water changes (7 to 10days), the tank water has a pH of 7.8. I use Instant Ocean Salt and my replacement water has a pH around 8.2. I believe that the shift in pH after water changes is stressing my system.  <Good point.> I have started to use Kent Marine's Super Buffer and now my pH stays at 8.3 and. Alk = 4 meq/l. Is this method of keeping up alk/pH up a good idea or would the two part supplements be a better choice? <Two part would be better.> I did read the article in FAMA as requested by you about the Ice Cap ballast running NO fluorescence. I remembered reading that article years ago and another (same concept) with a plant tank. It really sounds like they are having tremendous results with NO tubes and VHO ballast. My main question here is with tube replacement. Ice Cap says 6x longer life. The recent article in FAMA state that regular replacement of the tubes have been unnecessary. Also in FAMA with the other article on the plant tank he state that he has been running the same tubes for years. Now what puzzles me is that this is exactly opposite of what most say. Hmmm? <The use of electronic ballasts in these cases does extend effective lamp life as far as I'm aware, but don't know about six times, definitely not indefinitely. You can test for intensity, spectral make-up over time... or just observe your plant livestock for changes. Bob  Brad

Re: Algae problems - Please help Anthony, Thanks for the advice.  <quite welcome> What do you recommend that the dKH be at? 11-12? <yes...11-12 dKH would be fine...with a free calcium level over 380ppm as well there wouldn't be much to complain about> I had used SeaChem Reef Builder in the past but I think that I wasn't using enough or, the lack of strontium made it ineffective. I was also using C-Balance. Is there a product that you have had success using? <Once alkalinity and calcium are both in a reasonably good range... using the two part mixes is very good, just expensive.> I am using CaribSea pink Fiji aragonite fine sand. Should I just replace the whole thing or just take the thickness down to > 1/2 "? <Yes... if denitrification is not a concern/desire...else 3+"> I am not too convinced my skimmer is working effectively. I used to have an ETSS in sump reef devil. It just didn't seem to be doing the job correctly. I have just purchased a LifeReef Venturi skimmer. Again I purchased an "in-sump" model, for some reason I cannot get it to work effectively. I was using the in-sump models because of space requirements.  <in sump works best only if you have a skimmer box working as a standing overflow from which directly overflowing water is collected into a static vessel. Fluctuating sump levels are nightmares for skimmers> I am now considering a AquaC Remora Pro HOT and getting away from the sump for a few reasons. I had seen an article on a web page that had done a comparison between the CPR Bak-pak and the Remora Pro, both were used on a 38 gallon reef and the results were awesome on the remora. The second reason is that because of the fluctuation of my sump level evaporation), my current and previous skimmer performance would not be consistent. I would suggest staying away from in-sump models.  <actually easy to modify...simple diagrams on the net and in my book for doing so. You can then continue to enjoy the space savings. Tunze has an even better in sump skimmer that has a 4"X4" foot print and only needs 11-12 inches of water> I am also having a hard time dialing in for a thick effluent. (I think this attributed to the water level as well in the sump). <agreed> Lastly, the Remora is just plug it in and it works, obviously you would have to adjust the collection cup for skimmate consistency. < I still like Tunze and Euroreef skimmers better> Regards, Keith Broadbent <ciao, bub. Anthony>

Snowstorms Ca/Alk <it seems highly unlikely... are you confusing a simple temporary clouding of the water with the catastrophic "snowstorm"? A "snowstorm" is a sudden and severe crystalline precipitation of calcium carbonate that looks literally like snowflakes polluting and aquarium an is quite dramatic! Your calcium/carbonate levels plummet within 12-24 hours and it can be fatal to many, most or all livestock in the tank at times. When you say "snow storming" this implies to me that it happens to you regularly and such a thing is nearly impossible within weeks (gross neglect would be necessary). We should be clear on this term first.> Ah. Perhaps I am overestimating the significance of the crystallization I see. I used to see just a puff of white when I poured the stuff in that resolved in 5 seconds. Now I see crystals (like snowflakes ) that cloud about half the tank for about 5 minutes, then go away. The only chemical derangement has been the chronically dropping KH that DOES correct when I add a bunch more buffer. So maybe what I see as a snowstorm really isn't very important. It hasn't killed anything. Thanks :) <excellent my friend, and yes...agreed (and glad to hear it too!). An easy mistake when you haven't seen the other side (thankfully) to know what it looks like. Try diluting your supplements in a larger volume of seawater before dosing or add slower to reduce the cloudiness. In the meantime, do consider the two-part supplements. They are a little bit more expensive but work so very well! Kindly, Anthony> Tracy

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