Low pH and trying everything. What am I missing?

certain_code · Aug 10, 2015

I know there are a ton of threads out there talking about pH and how to raise and lower it. I know I shouldn't be chasing the number either since I am still within what is considered to be the "normal" range. I feel like my tank would benefit from a bit higher pH and was wondering what I am missing.

Alk: 160ppm (hanna)
Cal: 410ppm (hanna)
Mag: 1500 (salifert)(a bit too high for comfort)
pH range: 7.78 - 7.89 (AM - PM via ReefAngel)
Temp: 78-79˚F
Running a CO2 scrubber on my skimmer intake, house windows open for last 2 weeks or so
Other parameters in safe range (can post values if needed)
Tanks age: ~5 months

So what could I be missing? I was thinking the scrubber would certainly help but 5 days in and nothing has changed. Alk/Cal/Mag are stable and I am dosing daily with automatic pumps. My ATO is dosing Kalkwasser at the maximum mixture.

Ideally, I would be able to lower my dosing of kalk and 2 part and raise my pH. Coral and fish seem to be doing well but keeping SPS has been impossible for me in the last 2 months even with stable params.

Any and all help greatly appreciated. Struggling to find a solution that has already been mentioned on R2R or by Randy even.

Thanks!

Cory · Aug 10, 2015

Id say its a testing error for the ph. Id recaibrate it, taje a sample someplace, or try a ph test kit. That seems strange considerivg all youve done.

Downbeach · Aug 10, 2015

When was the last time you calibrated the pH probe?

certain_code · Aug 11, 2015

Honestly, it had been before I set up this tank so its been about 2 years. Didn't even think about this being the issue surprisingly. Going to have to find some #7 and #10 for the cheap and try to get it calibrated. I do have an API pH test kit but distinguishing the colors is something that I have never been good at.

TheEngineer · Aug 11, 2015

Another option is to open a window. Do you have the windows closed and the AC on? Just letting in some fresh air will raise the pH. I agree with what others have said and verify your readings.

ilovereefing <3 · Aug 11, 2015

How is your surface agitation on the tank? I would think if after calibrating your pH probe and ensuring that your readings are in fact correct, you could try additional surface agitation to help with gas exchange within your tank.

certain_code · Aug 11, 2015

icecool2 said:
Another option is to open a window. Do you have the windows closed and the AC on? Just letting in some fresh air will raise the pH. I agree with what others have said and verify your readings.

Windows have been open and using the co2 scrubber should rule out gas exchange I would imagine from what others have said.

ilovereefing <3 said:
How is your surface agitation on the tank? I would think if after calibrating your pH probe and ensuring that your readings are in fact correct, you could try additional surface agitation to help with gas exchange within your tank.

It's halfway decent but I have read usually when you think it is a lot it is still not enough. Going to calibrate my pH probe and then see where I stand.

toothman · Aug 11, 2015

Maybe the probe is bad. They don't last forever

beachsidereefer · Aug 11, 2015

cgaubuchon said:
Honestly, it had been before I set up this tank so its been about 2 years. Didn't even think about this being the issue surprisingly. Going to have to find some #7 and #10 for the cheap and try to get it calibrated. I do have an API pH test kit but distinguishing the colors is something that I have never been good at.

I had the same problem with my RKE PH monitor. Probe was out of calibration so it always registered low PH. Now I calibrate quarterly and no issues since!

Randy Holmes-Farley · Aug 11, 2015

cgaubuchon said:
Honestly, it had been before I set up this tank so its been about 2 years. Didn't even think about this being the issue surprisingly. Going to have to find some #7 and #10 for the cheap and try to get it calibrated. I do have an API pH test kit but distinguishing the colors is something that I have never been good at.

Let's see what happens after recalibration (assuming the windows are still open).

certain_code · Aug 11, 2015

Randy Holmes-Farley said:
Let's see what happens after recalibration (assuming the windows are still open).

Hey Randy, you don't happen to know a local place that carries #7 and #10 by chance? Boston area of course

Randy Holmes-Farley · Aug 11, 2015

Tropic Isle in Natick does. So do many others, I'm sure.

certain_code · Aug 17, 2015

Calibrated the probe and seem be be in the 8.4 - 8.6 range. I left the probe in each solution until it stopped changing so each solution took about 10 minutes. Was that too long? My params are still the same as before but now my pH seems too high? Best solutions for lowering it?

Going to cut my kalk dosage to help which is huge for me right now since I was dosing the max.

Thanks everyone

Randy Holmes-Farley · Aug 17, 2015

cgaubuchon said:
Calibrated the probe and seem be be in the 8.4 - 8.6 range. I left the probe in each solution until it stopped changing so each solution took about 10 minutes. Was that too long? My params are still the same as before but now my pH seems too high? Best solutions for lowering it?

Going to cut my kalk dosage to help which is huge for me right now since I was dosing the max.

Thanks everyone

Waiting 10 minutes is appropriate if it takes that long to stabilize.

I would worry about pH in that range, but if it drifts even higher, that's more of a concern.