Bubble algae isn't really "bad" its not poisonous but once popped or given the right conditions it will spread like wildfire and could potentially smother other corals or live aquatics in your tank. Your tank is really bad though, your only option to get rid of an infestation so bad like yours is to probably start your tank over. Unless you like the way it looks, but eventually it will probably start suffocating your livestock. If you do decide to start your tank over and get rid of it your gonna have to scrape it off of the glass with a really sharp puddy knife.Is it bad for the fish then
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