I leave it on 24/7. Needle valve is adjusted to 2bps. Been running like this for almost close to a year, no problems with tank or algae. I'm actually a shrimp and aquatic person, maybe the algae does exist but doesn't grow fast enough to where I can notice it before my shrimps chow down on it. I keep my light on 8 hours on a timing. I really haven't seen any major problem with keeping it on 24/7. I still get tons of lust plant growth.
If I wanted to, I can always turn it off at night and turn it back on in the morning when my lights switches on. It's fairly easy to adjust, you'll be suprised.