Hey Steve...
sorry...I've been on vacation..Just got back today.
I have to agree on the water change thing.
Seems like I change water so often..its alwasy going up and down and I think that might cause more harm.
Anyway...I used to raise a lot of south american fish.
Cichlids as well as angelfish and discus.
The fish that are part of the amazon river system can have really acidic water. Some of it is tinted almost like tea.
I used to put coconut shells in , but I don't know if they change the PH much.. I homestly dodn't remember what else. I think I used to use peat moss also.
Tints the water brown and lowers the PH.
When I raised a lot of killie fish...I used jiffy peat pellets .They breed in it and it tints the water also.
You can buy them on-line really cheap ( aquabid)
It can make the water look dirty, but it really isn't.
I think if you also treated your reserve water before changes...it would work.
The peat pellets work well because they are cheap and you can count how many you add and repeat yourself.
Hey...hows Houston after the hurricane?