I've heard this isn't true, seen people put them in a lot earlier than that and have good results. But I see where you're coming from that definitely can be a factor in why it isn't doing good in my situation. The algae is just coming from the ugly stage since that's right around the age my tank is at right now and I was previously dosing phosphate which might've fed the algae to get to that. Usually I end up turning the sand over once or twice a week.5 months Is too young for Gonis, plus you have an algae and a flow problem as well