Botanicare ph rising

Hi All. I'm having issues with botanicare pro soil line up. I have it set up with a circulation pump. Make sure everything is mixed thoroughly. Tweak ph to 6.3. But over a few days the ph starts to climb. It hasn't caused any obvious signs to the plants but must have an effect somewhere in the grow cycle. Any tips on how to keep her stable? I'm using a drip feed could it be that as it pumps out from the bottom it's taking more of certain nutes as they settle? If so same question how can I prevent this from happening. As it is I let it circulate after the final hand mix for two hours, recheck then allow it to feed. Thoughts and opinions appreciated as always. Cheers.

you could put a small pump in the bottom to circulate and aerate at the same time on a timer, full time..if you believe this is the issue

I have been using a circulation pump with a small fountain attached to the end of a length of hose to disperse evenly and add aeration. This has added to my confusion. Thank you for the reply.

What are you using for a down?

Mad Farmer has a nice down. Formulated to work harder with less. Lasts longer too....

Geoteck ph down.

Sorry. Geoteck ph up lol