It settles in the bottom on my refugium. There is so much life in my refugium. Remember the baby banggai cardinals I had in there? They are still in there and I’ve never fed them once. They live off the life in there. My refugium is not pretty but it’s pretty cool to go out there at night and see all the life in there.
Your chaeto won’t be stagnant with this light. I bought this light after d2mini did a video where he used this light and his chaeto grew so thick he was putting stuff on top of the chaeto to see how much it could hold.
Also I think maturity of the refugium helps with the hair algae growing in there as mine did the same at first.
https://www.amazon.com/MarsHydro-Sp...i=AC_SX236_SY340_QL65&keywords=mars+aqua+300w