Is it your sump or display...I would recommend hanging it st night direct in your display tank...I dont know how big your tank is but like I said work on 1w for every 3 gal ....I have a 36w on my 90gSorry i left a part out ive been running a 36w jebao UV sterilizer for about 2 weeks now and it hasnt done much
If your dinos are disappearing at night its because they go into the water Colom at night so UV should affect them ...also it's important how slow the water is passing through the UV...the slower the beter ..then theres more water contact with the UV light for longer

