Run UV sterilizer with to low flow rate?

[steallife904]

So I have my Aqua UV 25 watt sterilizer hooked up to my return line with a gate valve for flow control. I just did a test to determine what the gph flow through it is and it came out to 128.4 gph (filled a gallon jug in 28 second) which is super slow based off of what Aqua UV recommends. It looks like they recommend around 800gph for clarity and sterilization. Does this sound right? What could happen by running it with flow very slow? It's been running a few weeks now and I have not seen an negative side effects. What should I do?

 

[Flippers4pups]

Running at slower rates than recommend by the manufacturer is fine. The slower the flow, the more dwell time. BUT.... If ran to slow or if the UV is too small for the total water volume, it will be less effective. Certain UV sterilizers require a minimum flow rate to keep the crystal sleeve cooled enough so as to keep it from cracking.

In other words, I would follow the manufacturers recommendations for flow.

Hopefully I haven't thrown to much out there for you.