Ph too high

fishyman19 · Sep 24, 2014

My ph is sitting around 8.7-8.9 :frusty: I found out it could be due to a alk dose i was doing and have since stopped using the product and will be starting a different one this weekend. I've lost a lot of coral though. Is there any way to lower my levels or do i just have to keep up water changes and let it happen naturally?

DFW · Sep 24, 2014

I would say a big water change using a low alkalinity salt mix.

Randy Holmes-Farley · Sep 24, 2014

IMO, the pH is unlikely to be that high for long, and may be a testing error anyway. Even in a huge limewater overdose where the pH spikes well above 9, it rapidly drops to 8.6 or lower.

Don't do anything yet, since the pH may already be fine and the solution may be worse than the problem.

How are you measuring pH?

What is the alkalinity right now?

This has more:

High pH: Causes and Cures by Randy Holmes-Farley - Reefkeeping.com

fishyman19 · Sep 24, 2014

I'm measuring the pH with my apex system. I think I may pick up a different test today to just see if my apex is off or not. This morning it was at 8.7 and right now it is sitting at 8.76. When I stopped dosing on Monday my alk was sitting at 9.2

Randy Holmes-Farley · Sep 24, 2014

I'd recalibrate the pH probe, maybe with new fluids.

fishyman19 · Sep 24, 2014

Now I just need to find a place that has the fluids lol.

Randy Holmes-Farley · Sep 24, 2014

Yes, that's helpful.

o2manyfish · Sep 24, 2014

If you think you did overdose alk, perhaps soak the pH probe in Vinegar for an hour before calibrating it.

Also as an easy test if you have kalkwasser, mix up a batch of that and drop your probe in. It should read 12. That might give you an idea how far off your probe is.

Dave B

pirate2876 · Sep 24, 2014

My PH is constantly around 8.6-8.8 and I don't have any adverse effects. IMO I wouldn't do anything out of the norm.

Randy Holmes-Farley · Sep 24, 2014

pirate2876 said:
My PH is constantly around 8.6-8.8 and I don't have any adverse effects. IMO I wouldn't do anything out of the norm.

Just an opinion, but I've seen pH reports from literally thousands of reefers, and I don't believe you have pH that high unless you are dosing a very large amount of a high pH additive, such as limewater (kalkwasser).

Have you recently calibrated the probe that measured that? Are the calibration fluids new? pH 10 fluid goes bad over time (drops in pH) and leads to false high in tank readings.

IMO, if it really was pH 8.8, you'd rapidly have massive calcium carbonate deposits on pumps and heaters. You might even have a white out of full tank precipitation, which people do get when overdosing limewater (I've had it happen numerous times).

Randy Holmes-Farley · Sep 24, 2014

o2manyfish said:
If you think you did overdose alk, perhaps soak the pH probe in Vinegar for an hour before calibrating it.

Also as an easy test if you have kalkwasser, mix up a batch of that and drop your probe in. It should read 12. That might give you an idea how far off your probe is.

Dave B

FWIW, saturated limewater has a pH of 12.54 at 25 deg C.

coralcruze · Sep 25, 2014

I wouldn't do anything but water change. I would not do a large one but you could do several water changes with a few days in between.

zarfish · Sep 25, 2014

Sound like a typical calibration of the apex probe. I don't really pay attention to the value of the ph itself I just look at the daily swing. But when I see it gets up to the 8.6 8.7 I calibrate it and it has always been the issue.

kylarse · Sep 25, 2014

Ph probes can definitely foul over time. Most are not designed to stay submerged in a biologically active medium for long. There is a porous frit that allow ions to exchange from inside and outside the probe. If this is plugged by calcium, algae, bacteria, etc the reading will be off. My background is as a chemist where a PH meter is used, then rinsed and placed in a storage solution. It would be calibrated daily for the most accurate results. My RKE did the same thing to me a few months ago. I replaced and recalibrate the probe and my ph readin G was OK ag a in. Good luck, consistency of the reading is more important as has been pointed out.

Randy Holmes-Farley · Sep 25, 2014

Welcome to Reef2Reef, kylarse!

fishyman19 · Sep 25, 2014

Thanks for all the advice, I wasn't able to find any solution yesterday to re-calibrate the probe or a pH test that I was looking for to test compare, but I have a place I can look today after work. One question though and this is my noob mistake, but would it be better to just get a new pH probe? I either missed the boat or wasn't aware that it is wise to re-calibrate the probe on a monthly basis for best results. Actually I have never done a re-calibration on the probe at all in the almost 2 years of using it. I did a water change yesterday as well and now the pH is staying right at 8.7 but like everyone has said that could be totally off. So who knows.

Randy Holmes-Farley · Sep 25, 2014

I'd calibrate the probe and see if it can read the pH 7 and 10 solutions correctly after calibration. If it can, it is good to go.

If it has been two years, I'd soak it in vinegar overnight to remove deposits, then rinse well in tap water before calibration.

fishyman19 · Sep 25, 2014

Cool I'll give that a shot and see what it does when I can find some decent solution somewhere. Thank you.

Randy Holmes-Farley · Sep 25, 2014

You're welcome.

Good luck.

kylarse · Sep 25, 2014

You can get larger bottles 500 mL of calibration solutions on amazon. Look for fisher ph 7 and fisher ph 10 buffers. I put some in a small cup or old fashioned film cannister, and use it for a few weeks. Rinse in rodi water between solutions.