The friendliest place on the web for anyone with an interest in aquariums or fish keeping!
If you have answers, please help by responding to the unanswered posts.
Moldy? It probably isn't mold, but algae. It's completely normal and will continue to grow until it is taken over by coralline algae (the pretty purple stuff). Your tank looks pretty new, you'll be seeing lots of weird things as the tank stabilizes.
never mind I just read you meant the green part it's definitely algae and nothing to worry about at this point. Completely normal. Your parameters are probably off because the tank is cycling. You're going to see a few different types of algae as your tank matures, but eventually you'll want to balance light, phosphates and nitrates to keep algae away.