Sillyfishies
Aquarium Advice Addict
What PAR at substrate is enough for a DHG carpet? 40+ enough?
For DHG you will want to be in the 60+ range. The higher the PAR the better for most carpet plants. With high light, you will most likely need CO2.
I don't believe you get the growth desired at lower PAR. Yes it can be grown at lower PAR, but it seems to thicken up faster, and have a darker color at higher PAR. Just my personal experience. Everyones tank is different, so good results probably can be achieved in less light.
You'll definitely be good at 40+ PAR for DHG. Even HC can be grown at mid 30's.