you know those preformed filters with the black back...FYI

[Sk8r]

...DON'T use those in a qt tank where you're medicating or using copper. They're carbon. They remove meds and copper.

They're just fine for ordinary qt where you're just observing: they also remove ammonia...being carbon.

But I'd hate to see someone lose a fish because they thought they were medicating and they were simultaneously using those convenient little things. Use the bluewhite filter floss that comes in mega-sheets. Just cut to fit.

[OnoIgotICH]

...it says it on the back

[Sk8r]

Sure does. Some people, however, don't always read what they've always used---or don't know that the word 'carbon' is significant when dealing with substances in water.