Opinions on UV filters

I'm thinking about getting a canister filter for my tank and am wondering if I should get one with UV sterilization.

Also, since UV's effectiveness depends on both power and exposure time, I'm a bit confused about the UV specs on canister filters. They only list the power of the UV lamp but doesn't say anything about the depth/amount of water and duration. Is there an accepted standard / or typical rule of thumb that is used based on the filter flow rate and UV power?

Anyway, thanks for your help.

 

Yes dwell time is critical.

The wattage is also a factor as well the lamp design but I'm guessing that for most canisters you would need to back the flow off considerably to achieve anything like proper sterilisation. It might be better to add an inline steriliser that is designed and selected to suit your aquarium volume and maximum flow rate.

FYI I have one of these (the 10w model) and you can see from the table that I can't exceed 500 litres per hour or more than a 250 litre heavily stocked aquarium without compromising its effectiveness.

https://www.deltec-aquaristic.com/en/products/deltec-uv-sterilizer/

 

I have a Green Killing Machine 9w filter in one aquarium and my other three aquariums I have Green Killing Machine 9w airstone hybrids

They are on 12 hours a day, off overnight.

Rge fish...and Axolotl...have all perked up greatly since introducing them, some say they are a gimmick but my fish & Axolotl are happier, water quality is better for longer so I am happy to use them

 

Thanks guys. I'm now looking at inline UV setup. I didn't even know they have these for aquariums.

 

my understanding is they only remove algae from the water Colum which rarely occurs in tank.