PH of 8.8

[pommie]

OK, ive read all there is to read but i want to make sure ive not missed out anything obvious before i take any further action.

My PH has been high (8.5 - 8.3) as long as i can remember - Ive had the tank running for just over a year.

Yesterday i calibrated all my probes again with fresh calibration solution and now my Ph is reading 8.8 (day time) - 8.5 (night time).

The probes were definitely calibrated correctly, i checked with the solution after calibration and it read 10.0.

Its a 600Ltr tank with a relatively small Bio.

My parameters checked on Sat were:-

Dkh = 9.8
Ca = 500
Mg = 1400
Phosphate = 0
Nitrate 0.8 (i know that's high)
Salinity = 1.026

Since then i have chucked a couple of airstones in the sump but they dont seam to be making much difference.

Im dosing Red Sea reef foundation.
I dose Alk at night time.
I perform 20% water changes every week (using NSW).

Ive read that if all other parameters are ok, then ignore PH, but when its this high can i ignore it?

My next step was to try dosing with some vinegar but im not sure if that will be a short term cure or not?

Any advise appreciated.

 

[downbeach]

How old are/is the probe(s)? Is there any possibility of electrical interference? Unless you're using some type of high pH supplement, i.e. kalkwasser, I doubt that your pH is really that high. Have you added any man made rock lately? Using RO/DI water? I would get another opinion.

 

[Ron Reefman]

Borrow a pH meter from somebody and get a 2nd test with different equipment before you do anything rash.

 

[pommie]

How old are/is the probe(s)? Is there any possibility of electrical interference? Unless you're using some type of high pH supplement, i.e. kalkwasser, I doubt that your pH is really that high. Have you added any man made rock lately? Using RO/DI water? I would get another opinion.

The probes are a couple of years old.
I did test a while ago with the PH test that comes with the Red Sea test kit and that did indicate at least 8.4 possibly higher.

Electrical interference is a possibility though. I noticed the other day that i would get a a small shock if i had my hand in the tank and touch the outside of my ATI powermodule. I planned to get the looking into but assumed there was no completed circuit reaching the fish as they all seemed to be happy.

All rock was live rock from the LFS
All top up water is RODI.

I think ill take some water and get it tested at the LFS first.

Thanks

 

[bertoni]

8.8 for pH is hard to believe. It'd take a fair amount of lime to raise the pH that high. I agree that electrical interference or probe failure are reasonable possibilities. I wouldn't do anything drastic with the tank because I don't believe the pH reading. You didn't mention any animals having troubles, but if they are, a bit of soda water will lower the pH temporarily. Vinegar will have the same effect, but it also adds organics, which can cause problems.

 

[pommie]

8.8 for pH is hard to believe. It'd take a fair amount of lime to raise the pH that high. I agree that electrical interference or probe failure are reasonable possibilities. I wouldn't do anything drastic with the tank because I don't believe the pH reading. You didn't mention any animals having troubles, but if they are, a bit of soda water will lower the pH temporarily. Vinegar will have the same effect, but it also adds organics, which can cause problems.

Corals and fish appear to be fine.
With the probe i re-calibrated it with PH7 and PH10 solution and after calibration when i left it sat in the 10 solution it red 10.0 so i doubt the probe is at fault.

The electrical interference i think is more likely, but if my lights were causing some interference then surely the PH would drop dramatically in the evening when the lights were off?

 

[bertoni]

The light might not be a cause of electrical interference in your system. They were in mine. Any piece of electrical equipment is suspect.

You could try aerating some fresh saltwater outside for a few hours. It should read in the 8.2-8.4 range for pH.