Drop in pH!

[Jazzy cap]

Hello! I am really stumped! The pH in my 2 freshwater tanks that have sand as a substrate dropped down to 6.0, although the pH in all of my other freshwater tanks is 7.6! What could cause such a difference in pH? Anyway, I used crushed coral to stabilize my pH at 7.0, using 1/4 cup of crushed coral per 10 gallons of water. My corys are happy and active again following the addition of the crushed coral Any further advice or suggestions as to why my pH dropped so low?


Jazzy cap

 

[SherLar]

What other decor do you have in the tanks? I've never heard of sand causing a PH drop, but some types of woods and mosses can, I believe.

 

[TMaier]

Any change in water supply?