Diatom fun

[Somethingfishy_]

What’s this starting to grow on my heater? Tank is 6ish months old and has a little bit of a diatom probably or is still cycling. I’m under stocked and I underfeed. Nitrates and nitrites are in check.

 

[Fudsey]

Sponges maybe....

Are they hard or soft?

 

[Somethingfishy_]

Not really soft or not really stiff. They also seem to be stuck up there pretty good.

 

[Fudsey]

I still think sponge then. I have tons of sponge growing all over my tank and sump. Great filter feeders.