Corners of tank turned yellow

[Gourami Mommy]

So all of my corners in my aquarium are yellow on the silicone. Any clue why? Should I be worried about it?

 

[coralbandit]

Does it wipe off ?
Have you used any meds in tank [like furan 2]?
I have noticed that caulk and silicone airlines can grow a lot of 'bio slime/algae' myself.

 

[Gourami Mommy]

It does not rub off but there was algae and slime there before I cleaned Saturday. My snails love these spots so I’d wager a guess that they stay yucky but not with anything that’d keep the snails away.

I haven’t used meds, but I have used pHDown (comes out of the tap high), carbon, and fertilizer.

 

[drjallen3]

So all of my corners in my aquarium are yellow on the silicone. Any clue why? Should I be worried about it?View attachment 308721

Algae can stain silicone just like mold can stain it when used around a bath tub. I could probably be scrubbed clean but not recommend in an aquarium as it is get worked loose and cause leaks. Your tank looks nice even with the stained silicone because the rest of the tank is clean. Leave it be.

 

[Gourami Mommy]

Algae can stain silicone just like mold can stain it when used around a bath tub. I could probably be scrubbed clean but not recommend in an aquarium as it is get worked loose and cause leaks. Your tank looks nice even with the stained silicone because the rest of the tank is clean. Leave it be.

Oh, okay. That makes sense. I didn’t clean it for a while when it was cycling without fish in it . I bet it got stained then. Thanks!