Just curious if anyone would know how much heat/degrees is added to a 180 gallon tank from a 36 watt uv sterilizer? Flow is 50 gallons per hour and 24 Hours a day. Thanks
If installed correctly with proper flow rate they shouldn't add much or any heat to your system. 50 GPH is really slow flow rate (slower flow, better chance of heating water) for any U/V that size. I'm guessing this is a 36W Coralife unit (based on 36 watts comment)? That unit can handle 400-1,200 GPH and still sterilize as advertised. I would bump up the flow to the mid range if possible.
FWIW I plumb U/V's into the return line at full flow assuming the unit and return pump are sized correctly.