i have been given a l00 gallon tank and it is fishless and waterless. problem is it is covered with green hair algae. was considering filling it with rodi water and massive dosing with magnesium along with blackout. am looking for any input on ways to make it free of algae. I already have a 100 gal and this tank is doing good so i think lighting both natural and artificial can be replicated when i get it clean. thanks