first time heard using algae as plant. hahaha...What kind of algae you want? New tank water with high lighting sure can get BGA. If plus the strong flow of water. Then you will get hair algae. If water temperature went up, then you will get brown algae. But then algae will disappearing after your tank stable.

Beside that, CRS(Crystal Red Shrimp) need low PH like 6.2-6.6 max. You need to keep some mosses as the micro-organism will grow inside the mosses. That is the source of their food. What grade you want to keep? C? B? A? AA? AAA? S? SS?

And...your congo might take the CRS as their meal.