low alkalinity high ph problem

[RobReefer]

I did my weekly testing last week and found that my ph had jumped from 8.3 to 8.5-8.6, and my dkh was 6 instead of 10. I have been adding extra in my daily doses of Kent marine dkh buffer and it wont move from 6 dkh.

My salinity is 1.025, calcium 400, no phosphates, no nitrates, no nitrites, and no ammonia. I do dose with o3 and it is 390mv. I also use a phosban reactor, and a carbon reactor. I dose daily with Kent marine calcium and dkh buffer.

 

[bertoni]

You might want to test magnesium, but I am not sure that's the problem. I would avoid using the Marine Buffer in a reef tank since it has a lot of borate in the mix.

Are you sure the test kits are working? We seem to see a lot of testing issues, in the end.

For the moment, some baking soda would be a good way to add alkalinity with the minimal effect on pH. This calculator should help you pick a dose:

http://home.comcast.net/~jdieck1/chem_calc3.html

I'd get the alkalinity up to 7dKH and work from there.

This article discusses high pH problems:

http://www.reefkeeping.com/issues/2005-03/rhf/index.php

The Marine Buffer might be a high-pH supplement; I'm not sure on that. If switching to baking soda temporarily doesn't help, you might have a CO2 deficit.

 

[RobReefer]

I just got a brand new ph and alkalinity test, so I know they are working fine. I will try the baking soda and see what happens. Do you think that maybe my o3 is causing low co2 in my tank? I am filtering it with carbon.

 

[Randy Holmes-Farley]

I just got a brand new ph and alkalinity test, so I know they are working fine.

I am not a fan of pH test kits. Some are inaccurate, and even if you just bought it, you cannot know how old it may be. What brand?

What time of day did you measure pH? How low does it get in the AM?

Ozone does not cause low CO2, nor does it raise pH.

 

[RobReefer]

Well I just did another test at 10:00 am, and it was between 8.3 and 8.5. It is a Nutrafin test kit. I usually do my tests between 5pm and 8 pm. Randy what do you use to measure your ph? A probe?

 

[Randy Holmes-Farley]

pH will vary through the day. High at the end of the light cycle and low at the end of the dark cycle. The more aeration there is, the less it will vary. I use a pH meter to measure pH. Some are not very expensive, but all can be checked and/or calibrated with standard solutions:

Measuring pH with a Meter
http://www.advancedaquarist.com/issues/feb2004/chem.htm

A Comparison of pH Calibration Buffers
http://reefkeeping.com/issues/2005-02/rhf/index.htm

 

[RobReefer]

Stupid question does my high PH have anything to do with my low alkalinity?

 

[Randy Holmes-Farley]

No. Lower alkalinity leads to lower pH, other things being equal.

 

[RobReefer]

Thank you Randy and bertoni for your help. I am going to try baking soda today, and I ordered a ph meter that will be here Tuesday. Now all I have to get is some ph down.

 

[bertoni]

The pH Down product is sulfuric acid, if I remember correctly. I would be carefuly about dosing it into a reef.

 

[bertoni]

<a href=showthread.php?s=&postid=7317101#post7317101 target=_blank>Originally posted</a> by bertoni
I would use the Marine Buffer in a reef tank since it has a lot of borate in the mix.

I meant to say that that I would avoid using Marine Buffer in a reef tank. Sigh. I'll edit the post above if I can.

 

[Randy Holmes-Farley]

I agree to avoid pH down products as they will deplete alkalinity. Aeration and CO2 are better choices.

 

[RobReefer]

How can I aerate anymore. Doesn't the protein skimmer and o3 reactor aerate enough? I don't have a hood on my tank or my sump. On the calculator, it says that baking soda can lower ph. Sorry if I sound so confused.

 

[bertoni]

Baking soda will lower pH slightly when added. As CO2 outgasses, the pH will rise a bit. Both effects are fairly small.

If you have a good-sized skimmer, you might have as much aeration as is useful. In that case, adding CO2 to the water would be an approach to consider. A calcium reactor uses this approach to dose alkalinity and calcium, and could be used to control just pH by ditching the media. I think that's fairly expensive, although at least one person posting here has done that.

 

[Randy Holmes-Farley]

How can I aerate anymore. Doesn't the protein skimmer and o3 reactor aerate enough?

If your house had normal air (not polluted with excess CO2), then perfect aeration would peg the pH in the 8.2 to 8.4 range, depending on the alkalinity. f there is extra CO2 in the air (from breathing, for example), then the pH would be even lower.

No, skimmers are not perfect at aeration, although the help a lot. The O3 reactor, depending on the design, may not help all that much with CO2 exchange. Bigger skimmers, open sumps, air stone in sump, etc can all help gas exchange.

 

[RobReefer]

Oh ok. Well I am currently using a coralife super skimmer 125. Maybe I will go to the LFS and pick up a couple of air stones and drop them in the wet dry for extra aeration. I am going to try the baking soda tomorrow when my ph meter comes in the mail. I will let you guys know how I make out. I just wanted to thank you guys again for the help. It is defiantly much appreciated!!

 

[Randy Holmes-Farley]

:thumbsup:

Let us know how things work out.