UV

[elias]

Can anybody tell me how many hours should this kind of light be on, I shop in 2 stores 1 told me 24 hours a day and the other that I should put a timer for 8 hours at night .

 

[mr . salty]

I leave mine on 24hours a day.

 

[missycoral]

Hi elias, aswell i leave on 24/7 always have. goodluck, Missy

 

[beth]

Boy this is a much debated issue and every hobbyst will tell you differently. I leave mine on 24/7 but many reef hobbysts claim that so much UV is harmful to their reef systems.
If you basically have FO or FOWLR, leave it 24/7. If you have reef, then read up on the issues involving reefers concerns on this matter, then you can make an informed decision.