Is this coralline algae coming in? It’s in my nano and I’ve been waiting and dosing the booster. If it’s not, what do yall think it is? It’s this bright color under blue light.
Impossible to tell. Need pictures under white light and age of the tank. Coralline typically shows up on plastic parts long before rocks and glass in the tank.
Its more likely cyno…as above, coralline algae starts generally on powerheads, return etc and only a tiny dot at first, yours looks far to red and far to big to be coralline.
