pH probes

[Kens Bees]

My original Ghl probe kept reading low versus a handheld tester I have. That probe is over two years old so I wasn’t surprised. The handheld is pretty good and reads what I believe to be accurate in three tanks.

I installed and calibrated a new Apera pH probe earlier this week and it’s reading 7.8 right now. The skimmer air is always from outside via 3/8” tubing, the fuge is on a reverse light cycle. The handheld says the tank is at 8.15. The other tanks are also at 8.0 or better.

any thoughts on what’s going on?

 

[Chris A.]

Try aerating a cup of water with an air pump for a few min outside and then test again. It’s possible you actually have high co2 in the house.

 

[Chris.Reef]

What are you using for the handheld probe? Did you calibrate that one aswell? The constant monitoring ph probes should be referenced less for a accurate number and more as a trend due to how infrequent they are typically calibrated.