are you supposed to change your tank every two to three weeks

[algae]

Ron why are you supposed to change your tank every two to three weeks seems with an air stone that water stays fresh & nice would there be a problem going 8 weeks don't notice any algae or anything thanks for the advice

[Ron]

I don't change mine unless my plants show signs of a problem. I think that two week thing is just another lie put out by the grow stores so you have to buy more nutrient solution from them.