Hey guys and gals ...

I've just been running a Fluval U2 internal filter in a new tank of fresh tap water and today I noticed the water had gone pink ... I checked inside the filter and it had two rectangular sponges in excellent condition ... although each sponge had a black side and a PINK side .

I'm presuming that the pink side of each sponge is causing the water to go pink but is it temporary and is it dangerous or is it normal for a fresh set up ?

The filter is a used one and hasn't been used for a while .

Any ideas !!?


Thanks !