How Often UV?

[Mitch_ScruffyCityAquatics]

Over the past couple of years I’ve lost several Corydora to a bacterial infection. I’ve treated the tank with Maracyn, I’ve varied their diet (and added Vitachem), and I am running a UV sterilizer ever now and then. 
 

I’ve recently had several Mollies show symptoms of swim bladder issues, and I’m back to researching what I can do to protect my tank’s inhabitants. I do water changes weekly, typically 20% to reduce nitrates. The tank is heavily stocked and heavily planted so I change the water to reduce nitrates and allow me to fertilize with Easy Green (although I am thinking it may be time to go the Flourish route of dosing to meet my tank’s needs).

 

All of that to ask, for those who use their UV sterilizers to help with disease, how often do you run your UV lights when you don’t see problems in the tank?

[Jungle Fan]

I don't run mine unless there is a problem because it messes with the chelation of the liquid iron fertilizer I use and makes it unusable for the plants. So if I don't have to, I don't run it. The second reason is that it is an internal UV sterilizer, huge, bulky,and unsightly and I don't want to see that in my tank if I don't have to. I do 50% weekly water changes.

[Mitch_ScruffyCityAquatics]

That is what I had been doing. I have a UV in my canister filter so it isn't taking up any space in my tank.

Since I have been experiencing an issue lately, I have been running it about 8 hours every couple of days. Besides the five fish in quarantine I haven't seen any more Mollies living on the substrate... so hopefully it has helped keep the rest of my tank inhabitants healthy. The five in QT are currently enjoying some aquarium salt after a Maracyn treatment. Some may be doing better, and they may move back to the big tank in a few days. But sadly one of our favorites is still resting on the bottom.

Anyway, I am hoping there is a recommended preventive use that can help me keep such diseases at bay. I could also do larger water changes, but I've always been worried about doing 50% water changes every week. Maybe that is what I need though, I do have a lot of Mollies.

[Brian]

I run mine 24/7.  Changing the bulb every 12-14 months.