Welcome to The Reef Tank
I'm not a UV guru but I'll share what I know.
You'll get longer effective bulb life with a higher output (not wattage) bulb. The specs for tank size given by the manufacturer are usually overly optimistic so go for one rated at least twice your tank size. Make sure the unit is rated for SW and for SW parasites, you'll probably need to speak to the manufacturer or visit their website. Flow rates vary on what you want to kill, you'll need a slower
flow rate for parasites so make sure you get the correct flow rate. If the water is passing through the tube too fast, it won't be effective against parasites (UV specs for flow rate are usually given for algae) so once you have determined the correct flow rate, time it to make sure. Use a one gallon jug and time how long it takes to fill from the UV and then mutiply to get the GPH. You may need to change the pump you are using on the UV or put a
ball valve on the line to adjust the flow.
HTH some and that others who are more knowledgable than myself will chime in.
Alice
"A BRW Original"
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