PH spike

[thatfishnerd]

Hello,<br />
I am in high school and I have a research project that involves dwarf cuttlefish, breeding, sexing and so on but I'm not here to address that part of it. Today, I went into the lab to feed them and I realized that I had lost 7 of the 8 cuttlefish I needed to do my project. I did a water quality check, here are the results:<br />
Nitrates: 0<br />
Nitrites: 0<br />
Ammonia: 0 <br />
Salinity: 1.024<br />
And the kicker<br />
PH: 8.8 <br />
I have no clue what could cause a spike in pH, any ideas on what could've caused this?<br />
~Sean<br/>

 

[Randy Holmes-Farley]

Sorry to hear that.

How did you make the water?

Was it aerated?

Did you add anything to it (like buffers or other additives)?

How did you measure it?

 

[thatfishnerd]

I made the water with a Rio water pump to circulate while I dumped in instant ocean reef crystals, I had two air bubblers going in the net breeders that contained the cuttlefish. Could macro algae cause a pH spike?
Thanks for your help!!!
~Sean

 

[thatfishnerd]

I forgot, there were no additives.

 

[Randy Holmes-Farley]

My actual guess is ammonia, despite the test result. Kits are often faulty, especially ones that may have been sitting around a classroom for years.

Did you cycle the tank before putting in the fish? If so, how?


Back on pH, how did you measure the pH?

Nearly all high pH measurements in the absence of high pH additives turn out to be measurement error. It isn't something that "just happens". I've seen this reported many, many times. All (or nearly all) were measurement error if not using high pH additives.

Macroalgae, if photosynthesizing enough will raise pH, but not generally to 8.8 or to any level that would be harmful, unless the aeration is poor.

I also don't think pH 8.8 will kill most fish. I've overdosed limewater several times whether the pH likely got that high or higher and no fish died.