from a post I made in Chit Chat......
If you have ABS pipes in your tank. You might want to take them out. I was reading some DIY sites online and came accross this......
>> I've seen black PVC in the drainage and irrigation
>> section of Lowe's and Home Depot.
> The reason it is in the drainage and irrigation
> section is because it isn't PVC. It's ABS, and in
> the US is illegal to use for supply plumbing.
> In continuous contact with water it will leach
> chemicals used in plastic manufacture known
> as "plasticizers". These things are toxic, and I
> would strongly recommend against using it in your
> aquarium.
Source
I haven't noticed any harmful effects with my fish, but I took it out anyway just to be on the safe side. Figured I'd post here in case anyone else has ABS pipes and just assumed that since PVC is "safe" for aquariums, that ABS would be as well.