I'm not sure yet what i will do. I'm thinking of removing the cup and replacing it with a small piece of driftwood or a nice river stone. The cup was only really there for something for the catfish to go in when i didn't have plants. My only concern with driftwood is algae. Algae never touches my plants but it loves the glass, pump, heater etc. All very easy to clean off with a toothbrush but driftwood would be hard to clean. I'm open to suggestions.