Told I should be over here.

[Oddball]

Welcome to MFK!!!

CA waters are pretty alkaline. The only way I've been able to properly adjust the pH down was by using RO water. Your african cichlids won't appreciate it since they prefer alkaline conditions. You may want to stay with them since you'll have a hard time finding/getting FW rays in CA. They're on the Restricted Species List and are only allowed, by pre-inspected permit, in institutions.

 

[HarleyK]

Howdy & Welcome to MFK!

It greatly depends on your kH if you can lower the pH with CO2. It is far easier and cost-efficient (especially in a tank your size) to use R/O and peat, as suggested above.

HarleyK

 

[FishHeadSoup]

I live close by from ya and dont mess with my ph at all, my ray is happy.

PM if you want to chat more...