[Aquaticfan]

High light and low nutrients cause plants to struggle. If they lack nutrients with high light they start to fail. Just as Tom pointed out in his use of the forest sceniario if you cut down the forest will there still be weeds? Of course. Probably even more. Algae will exist no matter what but we can do our best to limit it and control it by good means of growing plants well and using methods like amano shrimp in numbers along with good circulation and co2 levels will help. It's not about competition between plants and algae its about growing plants well.

Remember light is what drive plants needs and growth. Same goes for algae. Algae is much like a weed. Opportunistic.