WEIRD PH?

have you followed the right way as told by the instruction on your water test kit? Because if you don't that's basically what's goin to happen

What kind of rocks and ornaments are in your aquariums? As for the ornaments, I mean what are the made of? Plastic, ceramic, baked clay, wood, or...? Are they painted or dyed? What are you using for substate? Is it painted or dyed? What color are these are these paints and dyes? And what do you feed your fish? Have you treated your water with any chemicals recently, like water conditioners or fish medications, and if so, what were they?

In the most fundamental of terms, a pH increase is an increase in the amount of Hydroxide ions present in the water relative to the amount of Hydrogen ions. Thus, something is bonding with those Hydrogen ions, skewing the ratio. Otherwise, something is contributing Hydroxide ions to the water. Those are the only two options here.

If we know what is in the aquariums and what is being put into them, we should be able to isolate the cause. If the cause cannot be found there, it is likely human error in the pH testing.

Cheers,
Puddin'