Hello everyone! Its been a while since i posted anything. After I lost my seahorses, I was bummed. We anyway, I got a great deal on a 50g tank for 100$ and it came with a yellow tang, 2 clownfish,and 2 zebras. My lil 15g already has 2 clownfish, a baby blue tang and a black neon fish. (Forgot what its called. Anyway... the tank I just got has the filtration in the back of the tank. She never cleaned her tank. I'm telling you, algoe was was/ is so stuck on there and smells terrible. Where do I start? I cleaned the inside of the tank but left the bio alone.im just going to change the blue/white filter. Besides the water changes,anything else i should do? I know its bad,all my fish is in the 15g temporarily. This is the 15g pic