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FAQs on Marine pH, Alkalinity, Products by Brand Name, Manufacturers

Related Articles: pH, Alkalinity, Marine Alkalinity, Synthetic or Natural Seawater, Water Changes/Changing, Understanding Calcium & Alkalinity,

Related FAQs: Marine pH, Alkalinity 1, Marine pH, Alkalinity 2, Marine pH, Alkalinity 3Marine pH/Alkalinity 4, Marine pH 5, Marine pH 6, Marine pH 7, Marine pH 8, & FAQs on pH: Importance, Science, pH Measure/Test Gear, pH Controllers & pH Buffers/Buffering, pH Anomalies (Troubleshooting/Fixing), & Marine Supplements 2

pH raisers, buffers, salt mixes... Baking Soda (Sodium Bicarbonate), Washing Soda/Soda Ash (sodium carbonate), Kalkwasser (Calcium Hydroxide)...

Re: E. Pacific Anemones husbandry     4/26/20
My total water volumes consists of a 35 gallon display aquarium with 1" acrylic on all the sides and bottom.
<Good for insulation>
I have a good 1/10hp chiller and haven't had any issues maintaining 55.5-56 degrees F, which is currently
my target temperature.
<I'd let this up during the summer/warmer months... high 50's, low 60's>
In addition to the anemones I have many macroalgae and so I have strong lighting optimized for plant growth, though I've considered switching to bluer light for aesthetic purposes.
<... the strength of lighting is a relative term... 40-50 PAR, PUR for 8 hours a day is fine>
Plenty of flow between return pump, chiller pump, and two DC Tunze powerheads. Plenty of bio media. I am planning on drilling the aquarium and adding a sump to increase water volume.
<Ah, good>
My ph has stayed fairly low around 7.6-7.8- I think the chert rock and sand (common in my area) contributes to this.
<I'd be adding a commercial supplement here. SeaChem Stability is a fave>

Nitrates and phosphates have stayed high, especially phosphates (0.4mg/l, nitrates around 25mg/l).
<Not a worry>
From my discussions with other keepers of coldwater aquaria, these slightly elevated numbers are not uncommon but I would still like to get them down. When I add the sump I'll have a lot of options there, so I am not too concerned.
<Good... DSB there, RDP... BobF>
Re: E. Pac. Nems, now pH boosting       4/30/20

Thanks for the pointers. I have dosed a lot of Dr. Tim’s one and only and a lot of Microbacter7. I'll certainly add in some Seachem Stability as well.
<Do add this last when you do your regular water changes, pre-mixed>
Do you think that will have an effect on ph?
<Oh, yes; should boost over time. A little higher each water change, then dropping some... then up.>
What do you think of dosing sodium carbonate?
<The SeaChem product should be fine alone. You could add both though. Bob Fenner>

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>

Advice on Additives, buffers, for Coralline culture 3/18/10
Dear Sirs
I have a 29 gallon bio cube, filled with 40 pounds of live rock. It was recommended that I use purple up to help with the coralline.
I was also told use one of the other reef buffer. Which buffer would you all recommend since I am new to reefing.
<Any of the name brand buffers should be fine, Kent, Seachem, API to name a few.>
Dominick Perrone Jr.

pH And Baking Soda 8/5/09
Real quick question for you guys. I've been dosing baking soda lately in one of my 29g QTs, not a lot but I'm treating a fish in there with Cupramine and I've noticed my pH slowly dropping.
My procedure is I take a cup of tank water, mix in 1/4 cup of pure baking soda (unscented) and then pour it into the tank when I'm doing a 25% water change which happens every 2 days.
Long story short, my pH still is reading around 7.9 to 8.0.
On a whim, I ran my cup of mix out to my main 210g tank with the electrical pH probe and dropped it in there. It dropped from my tanks steady 8.2 pH to down around 5 before I pulled it out. I mean it dropped really fast down to there, like within 10 seconds it was down to 5.
Is that actually correct or is my probe just freaking out because there was so much baking soda in the cup?
<Freaking out, after adding buffers, pH readings will not be accurate for a few hours.>
1/4 cup of baking soda in a glass tends to make it look almost like milk but it clears up right away when dumped into the aquarium.
Anyway, any help you can give on this would be great. Thankfully my main tank keeps a steady pH so I've never had to deal with pH problems but this one is starting to alarm me and would certainly indicate why I cant get my pH in the QT up above 7.9, if the baking soda is actually driving down the pH. I only started putting in baking soda because of reading some article's of Bob about QT and doing freshwater dips, he suggested the way to get a good 8.3 or so pH would be to mix in a couple tablespoons of baking soda
to the 5g bucket of fresh water.
<Take a dKH test several hours after the baking soda is added. A dKH of 6-9 will be needed to maintain the proper pH long term. A pH of 7.9 is not dangerous as long as the fish is drip acclimated before returning to the main display. You may want to compare your pH test reading with that of the electronic pH device.
Your test kit may be reading low.>
Thanks for what you guys and gals do, I've learned a lot on your site!
<You're welcome. James (Salty Dog)>

Re pH And Baking Soda 8/6/09
Thank you for the quick answer.
<You're welcome.>
The only reason I haven't tested my QT water with my electronic probe that is hooked to my DT is I'm afraid of ich or something transferring into the QT. I'm religious about not ever using the same tube, net, container, NOTHING from the QT ever touches the DT.
<A good practice.>
Will dipping an electronic probe (just the end) in bleach after I test the QT water hurt the probe? If not, I'd be willing to try that.
<Not full strength for sure. Just four drops of bleach in a quart of water will disinfect/kill most anything placed into it, and should not damage your probe.
Allow the probe to be in the solution 15-30 minutes and rinse the probe well in fresh water before returning to your display tank.>
Also, you mentioned the dKH has to be up around 6-9 to get my pH to be stable long term... will baking soda raise dKH or does it only just temporarily raise pH? For instance, if I continually add baking soda, will my dKH eventually get up there or is the baking soda just a band aid to the pH problem and it wont fix it long term?
<What lowers the pH is the presence of acids in the water. When this occurs, the buffers in the water are neutralizing the acids, and when the buffers are exhausted, the pH will fall. Baking soda will not appreciably raise the pH, but provide more buffering ability to maintain it. To raise 50 gallons of tank water by 1 mEq/L will require about 16 grams of baking soda.
Since a level teaspoon of baking soda weighs just under 6 grams, then 1 teaspoon will raise the alkalinity in that 50 gallons by 0.4 mEq/L (1 dKH).
To raise the pH, you will need to use a product such as SeaChem's Marine Buffer which is designed to adjust pH to 8.3 and maintain both pH and alkalinity(dKH).
Reading here will provide you with a much more detailed explanation of the subject. http://www.wetwebmedia.com/alkalinity.htm>
Thanks again, you guys are great.
<You're welcome. James (Salty Dog)>

Proper ph (product) question  -- 10/24/07 <Hello Zach> Will proper ph cause a problem to corals if it is put directly into the aquarium? <I'm not a big fan of products like these, as while they may temporarily "fix" the issue, the causation of the problem has not been addressed. Normally this is a non-issue in a reef tank. How about supplying more details regarding your tank and let's try to determine the real issue. What is the pH? Alkalinity? Contents of the tank? Last water change? Tell me all about your tank.> Thanks, <Take Care -- Brian Griffin> Re: B-Ionic Calcium Buffer System Dear Crew, I did get an answer..... Steve <Ahh, thank you for sharing. Will post. Bob Fenner> In a message dated 4/24/2005 " Dear EVS,  When using your 2 part buffer system can you use just 1 of the solutions. Example: my calcium is at 425 and my alkalinity is at 7.2 can I just use part 1 to raise my alkalinity? Also if the situations were reversed and I wanted to just raise my calcium could I just use part 2? Thank you for your time in advance. Steve" Steve, Sorry for this late reply. No problem using more of one component than the other in order to tweak the chemistry back in balance. Be careful with the component 1 (alkalinity) in that you don't exceed 1 ml/per gallon per day and/or allow the pH to exceed 8.45. Best Regards, Bob Stark (ESV)

Seachem marine buffer 8.3 and Kent nano reef  01/01/2006 Hi, first of all happy new year to you all :D <And to you>      I've been running my tank for quite a while now and my pH seems to be fluctuating between 7.8 to about 8.0.   I believe it seems a bit on the low side and was wondering if adding Seachem marine buffer 8.3, i.e. the one that says will maintain pH at 8.3  would be any good to my system. At the moment I'm not adding any additives, just salt water  only.   I was hoping to raise the pH to 8.2 or 8.3. My alkalinity at the moment is around 8dKH and I hope adding SeaChem's marine buffer won't over dose it to ultra high dKH. <I like Sea Chem's Reef Builder, will increase dKH gradually.>      Also a side question.  I want to eventually keep LPSs, I understand they use calcium. My calcium is around 370 ppm at the moment and was wondering if the Kent nano reef 2 part do well if I also use SeaChem marine buffer at the same time ? Would the SeaChem buffer or the part B Kent nano reef be affected by each other in terms of alkalinity etc...as I do not want to get silly high dKH. Yet keep my calcium around 430-450.  <Personally I don't like the Part A/B additives.  Your best bet would be Sea Chem's Reef Builder and Reef Calcium (both in the dry formula)>.      Everything else is fine in my 20 gallon tank :D only got a single zoo polyp (there's an old anemone next to it that's disturbing it slightly though and I can't get it away from my zoo :(   - came with my live rock) and a mushroom rock. Thanks for everything and good health to you all for the new year :D <Thank you.  James (Salty Dog)> Ern

Re: Seachem marine buffer 8.3 and Kent nano reef  - 1/6/06 Hi again, sorry to trouble you again. <Not a problem>      I have dosed SeaChem's Marine buffer 8.3 and my water parameters which are relevant are at dKH of 11 I believe. I was using Nutrafin's KH/GH test kit and KH was determined at 210, which I divided by 17.9 to obtain the dKH value. <OK>      My water pH is at 7.90 this morning, I believe it is still a bit on the low side though I do not want to buffer the water any further as that may lead to over buffering with little effect on my pH. <Yes, your dKH is OK.  The ph isn't dangerously low.>      My aim is to get morning pH to 8.2 or 8.3 however I am unable to achieve this and do not know how to solve the problem. I tried the aerated water test, by getting a cup of water from the tank and aerating it outside in my garden for 5 minutes, stirring it vigorously. I manage to obtain a pH rise of 0.05, i.e. my reading was 7.95.      Does that mean my CO2 level is causing my low pH in my tank or could it be other reasons ? I have only 2 clown fish and a mushroom rock together with 22 lbs of live rock, a Prizm skimmer by red sea and a SEIO 820 pump for flow and MH lighting all in a 20 gallon tank. <I always recommend aerating make up water and water used for water changes for 24 hours to remove excess CO2.  And yes, CO2 will lower your ph along with any other acidic conditions that exist in your tank such as uneaten food, detritus in the sand bed/substrate etc.  Do you vacuum the substrate during water changes?>      Please advise. I'll be trying to test my newly made salt water in a few days when I do a water change to see if it is the salt mix. apart from that, would there be any way on such a small tank to increase pH to 8.2 / 8.3 safely without increasing KH further. <Ernest, unlike salinity, heat and nitrogen levels where the more you add the more you have, you cannot add ph, its not a substance, it is a measurement scale of the hydrogen ion level in water which indicates the acidity conditions.  Keeping nitrate levels low, weekly water changes, vacuuming the substrate and a careful feeding routine all contribute to reducing acidic conditions that cause low ph.  Do monitor dKH at least on a weekly basis.  Another point is to clean your skimmer cup weekly.  I use the same skimmer on my 30 mini reef and it is amazing how much gunk gets collected in the riser tube in this short time.  In not doing so greatly reduces the effectiveness of the skimmer.>    Thanks, you crew are always helpful and I very much appreciate your help. <You're welcome.  James (Salty Dog)> Ern

Adding Bi-Carb Soda for Ph    3/31/06 Hi Bob, <Joe> In your book you mention adding Sodium Bi Carbonate to maintain the required kalinity in a SW tank. I am confused as to whether your prescribed amount of 5 grams per 20 gallons is what we should add each week based on the entire volume of system water or just the amount of water that we are replacing? <Better just for replacing. The actual bolstering and maintaining of "enough" alkalinity is a bit more involved, and for the majority of systems can/will be "made-up" with regular water changes. For some folks... with lots of life/metabolism, feeding, inadequate "other" sources (substrates, live rock), commercial alkalinity prep.s containing carbonate/s, borate/s are sometimes a good idea> Also, does Sodium Bi-carbonate have a limiting Ph (i.e. it will not go higher than a certain ph value regardless of how much is added)  or will it keep raising the Ph past the desired range of 8.0 - 8.5? <Does have a limit... all else "being equal" (what universe is that?) Sodium Bicarbonate will not elevate (by itself) pH more than about 7.8> Although sometimes I get confused as to whether Bi Carb Soda raises the pH or the alkalinity?? <Will... as you will see through experimentation, application. I do wish I had the capacity to "re-teach" folks such important concepts as "non-Euclidean" thinking... basic chemistry that is non-linear, multiple factored... instead of hints and glimpses as here. Perhaps a stint back as a H.S. Science teacher would do me. Bob Fenner> Thanks, Joe

Low pH   3/16/06     I have a 72 gallon reef tank with the salinity at 1.024, the kH at 12dkh, the calcium at 400ppm, and my pH is at 7.8-8.0.  I've tried taking a bucket of the tank water and aerated it outside with a power head on the bottom pushing the water up, did not help, I talked to different LFS and it does not make sense to them.  I tested my water when I make it and is has the same pH of 7.8-8.0 as my tank. <Mmm, could be your salt brand/mix... this pH is not terribly low though...>     I have a SpectraPure 4 stage RO/DI unit that I run my water through, I aerate it for 24hrs. and the pH is at 6.9-7.2.  I add a 1/2 tsp. of Kent dKH buffer.  I let is aerate for another 24-48hrs with the power head on the bottom of the bucket, my pH is then at 8.3-8.5.  I have a bucket of water that is just buffered  for top off and one that I add salt to.  When I add the salt ( I've tried Oceanic, Oceanpure, and Instant ocean ) <The last is best/better> to the water the pH drops from the 8.3-8.5 down to 7.8-8.0 instantly and stays there, even 48hrs. later, I buffered the salt mixed water after 48hrs. up to 12dkh even tried up to 14dkh, after 24hrs the pH is back at 7.8-8.0. <Mmm, might be your "tester"...>      I have thoroughly read through the other situations posted on your site and could not locate a situation like this. If you have any suggestions please let me know, which I will greatly appreciate. Your site is an excellent site with a huge amount of information that has been very helpful to me in learning the hobby as my setup is going on 2yrs. old. All my fish and corals look healthy which is the main thing. <Well, there are other chemical prep.s you could avail yourself of... but if it were me, my system, I would first, check your checker... with another pH test kit/device, and not be overly concerned re the measures you list. Rest assured, many aquaculture and public aquarium settings have far lower values. Bob Fenner> pH and Calcium supplements 4/10/06 What product do you recommend to raise pH and calcium levels? <<Be sure you understand and test for Alkalinity.  pH measures how acidic or basic the water is.  Alkalinity measures the buffering capacity of the water, or in other words, the ability of the water to resist changes in pH.  Both are very important, and alkalinity is widely under-appreciated.  In any case, Kalkwasser is very useful in supporting pH, Alkalinity and calcium.  It is cheap and easy to use.  Grocery store pickling lime can be substituted for cost savings.  B-Ionic by ESV, C-Balance by TwoLittleFishies and TechAB by Kent are all two part preparations (one part calcium, one part alkalinity) that work extremely well and are extremely convenient to use, but are somewhat expensive.  There are recipes for "home brew" two part additives floating about the internet, but are probably best followed only by those with some chemistry background.  Last, but not least... you can use commercially available dry calcium and alkalinity additives. They are cheaper than two part additive systems but require a bit more care in their use.  Tropic-Marin makes a great dry product called BioCalcium that adds calcium and alkalinity in one product.  Any of the above can work very well.  Best Regards.  AdamC.>>

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