Refugium light on 24/7? bad? good?
 

so i have some cheato and some red algea stuff growing in my refugium
I want to battle away the little bit of hair algea that is left in my display. I also seem to get alot of algea on the glass after about 24hours from being cleaned. is it ok to leave the refugium light on 24/7 or should i not? whats the downside?

also will this help with water clarity?

It is my understanding that the Macro algae, as any other photosynthetic plant, needs its "down time" of the night.

Most will run the refugium on a reverse lighting cycle from the tank. This helps curb the PH swing that occurs at lights out.

ya i have it running reverse cycle currently. so what else can i do to kill hair algea and clear up the water?

Possible solutions:
NP Biopellet reactor
More water changes
Feed less
Reduce your photo peroid
Biological control such as a lawnmower blenny
Run Carbon/ A Ferric Oxide media
Swap out your filter sock every 5-7 days

chaeto can be lit 24/7 with no ill affects.
gives you nuisance less of a chance to gain or improve on a foothold.

i was looking at the NP Biopellet but i dont want another reactor! (havent even setup my calcium one yet).
the lawnmower blenny doesnt eat film algea though right? thats my biggest annoyance, the HA is very little and it seems to be going down.
For the carbon, can I run that in my sump? maybe just a large bag of it?

Lawnmower blennies do eat film algae. It would'nt hurt to put a bag of carbon in your sump. I just use a HOB Magnum filled with carbon on the side of the sump. Pretty simple, just change out a cup once a month.