Could this be the Problem?

[MadReefer]

I pulled this rock out as it looked black in the tank but is covered in slime green. It smelled horrible so I tossed in a bucket with water, vinegar and peroxide. Will see in a week or two and decide to keep or toss.

 

[MadReefer]

I also decided to clean that black foam in the sump. Why did Red sea think this was a good idea as it was a bitch to get all 5 sections out. I ordered another that I can cut to size to make cleaning easier.
These were dirty but not as dirty as I though as I have not cleaned it since the tank was setup in Jan 2027.

 

[MadReefer]

Last week add some Rowaphos to help reduce Phosphate and barely moved. I used what little I had. Today added a small bag 3x3 of Phosguard.
Now the waiting game. I hear the Jeopardy tune playing in my head now.

 

[nvladik]

That’s not Red Sea. Theirs come as a single foam insert.

 

[MadReefer]

That’s not Red Sea. Theirs come as a single foam insert.

I bought one and cut it to size. So one piece now.