Reducing high pH...

[reefm]

My average pH jumped from 8.3 to 8.6 (Apex probe). I know why it happened, it's a direct result of me replacing about 50% of my existing reefsaver LR with tonga rock, just looking for ideas on how to bring it down again. I can temporarily reduce pH w/vinegar but it creeps up to 8.6 in less than a day.

Fish are in QT. Sand bed, rest of rock and cleanup crew stayed in place. Tank has been up ~7mos and doing well otherwise. sg 1.025, Alk 10.4, Ca 410, Mg 1320, Amm/Nitrites 0, Nitrates 5, Phos 0.

 

[Downbeach]

When was the last time you calibrated your probe?

 

[reefm]

When was the last time you calibrated your probe?

2 months ago, when I got the Apex. Just to clarify, pH increase coincides with the LR removal.

 

[Robthorn]

It is strange that liverock change or removal would cause this but strange things happen.
I would at least check the calibration with a known solution just to be sure.

Do you use kalk or dose a buffer?

 

[reefm]

I can certainly re-check calibration later today, doesn't hurt.

no dosing/buffers, #s maintained via water changes.

 

[Robthorn]

Some salts mix to a high ph for some reason but normally settle down overnight. What brand salt do you use?
I can't be positive but I believe flux from surrounding electrical wires or motors can have an effect on many kinds of sensors. At least something else to mess with and try.

 

[Randy Holmes-Farley]

There is NEVER a time in reef tanks when the pH is too high (which, IMO, would be above 8.6) without overdosing a very high pH additive such as limewater/kalkwasser.

No real calcium carbonate rock can do it, but cement based rock can if not fully cured before use.

So if the Tonga rock was real, there is no concern about high pH and the pH may be an error.

 

[reefm]

you guys are spot on, I recalibrated the pH probe and pH is now showing as 7.9. thank you!!!

 

[Randy Holmes-Farley]

You're welcome.

Happy Reefing.

 

[Robthorn]

Haha. Now you need to open a window or two for a couple hours and watch it get into a more natural range and flush your house out so it is a more healthy environment for you, your family and your aquarium.