Please advise on how to interface UV...

[Aquaculture]

I've recently got myself a UV and am unsure on how to integrate it into my tank.

Currently my set up is,;

Canister filter -> CO2 reactor, then back into the tank

Do I place the UV before the filter as in,

1) Out of tank -> UV -> Canister filer (outlet) -> CO2 reactor, or

2) Out of tank -> Canister filter (outlet) -> UV -> CO2 reactor, or even

3) Out of tank -> Canister filter (outlet) -> CO2 reactor -> UV

Thanks for your recommendations in advance

[ranmasatome]

i think it should be the last option, if it was my tank.. i would hook it up like so.

[Aquaculture]

Thanks for your valuable commends ranmasatome, Shall go back and hook it up.

[eagleray]

Initially I hooked it up using option 3 ...then changed it to option 1 after reading some articles in the internet

I was trying to get rid of green water ... and a lot of the UV were used in pond situations ...but I guess it is the same for aquarium

the idea is that suspended green algae is too small for the filter to remove ... you put the UV prior to the filter ...so that the UV will zap the algae. When the algae dies, it will clump together , so it needs to be remove by the filter prior to water returning to the tank

Have been using configuration 1 for about 1.5 weeks .. so far everything good

And I can finally see my plants