Slowly Rising PH, help please.

[WaterMarque]

I have a new tank. It’s been cycling for over a month and about two weeks ago started registering 0 ammonia, 0 nitrite, and 10 nitrate. Also salinity has been between 34 and 35, currently sitting at 34.5.

Last week I added snails (3) and crabs (2). Small guys, all seem to be doing well.

My PH however has been climbing. Was 8.0, then 8.2 the following day, 8.48 yesterday and 8.5 today.

What could be causing this? I’ve fed the crabs twice, small amount of frozen food thawed out, not very much. I’ve done a water change as well. Haven’t had this issue before and want things really stable before we add fish in a few weeks. Any ideas on what’s causing the PH creep and any advice on how to lower it?

Tank is 45 gallons, I use a Hanna stick tester.

 

[Stephen8169301]

Did you open windows or have any fresh airflow in your house

 

[WaterMarque]

Did you open windows or have any fresh airflow in your house

Tank is in a basement. Newly finished basement. I would say there is airflow down there and the temps are usaully cool year round. But is that a contributing factor and if I should look into that what am I looking for?

 

[Dennis Cartier]

I would not try to lower the pH as it is probably not accurate. Unless you have lots of organisms photosynthesizing and the tank is not aerated enough, you are not likely to see elevated pH levels. Dosing with high pH supplements, kalkwasser, sodium hydroxide, etc. can also raise pH above normal. Being a newly setup tank, I expect neither of these to apply, so the Hanna is probably not returning an accurate measurement.

To confirm this, try measuring the pH of newly made up saltwater with the Hanna. It should read in the 8.3~ range.

What rock are you using in the tank? Any DIY reef rock in use? Newly made concrete based reef rock can elevate pH and alkalinity if not properly prepared.