Uv sizing questions

[loganjude]

I have a 375 gallon display with about 300 pounds of rock and 2 inch sand bed. Have a tideline 48 sump that should hold about 40 gallons at 9 inch water level.

I'm looking at lifeguard uv. Question is do I need the 90 watt or will 55 watt be sufficient. Seems I'm just over the water capacity for the 55.

Also 3 in vs 5 in? Leaning towards the 5 in for contact time. And what kind of flowrate for recommended watts? They dont seem to have that info.


Appreciate all info and merry Christmas!

 

[BoaConservationist]

way undersized, 400 gallons requires EXTENSIVE uv. In my hands here im going for dual 90w, one at a 10-20% flow and one at full rate

1 w per 3 gallon to have the ability to tune for what you need - otherwise dont even bother - also, time / bulb degradation, bigger bulbs output longer

if you are just trying to cure an issue you can confirm, or polish water, a single 90w should tackle it, but permanently running I would do two, parts will fail, and sudden uv loss on a system thats used to it can be crashy