Installing Aqua UV 25w sterilizer-Confused a bit

slojmn · Feb 13, 2019

I have two manifolds T'd off my return line for any additional reactors, etc. I run a Vectra M1 pumpat a pretty low return rate. I figured I could hook the sterilizer off one of the manifolds. But then I got to thinking and reading, it seems if I run it off the return line and dump it back into the return section of my sump it will just be cleaning the same water to some extent. I had the manifolds put in the return line for any additions I needed to run. Am I right in thinking if I T it off the return and return the output from the sterilizer into the return pump area its double treating?
I've looked at some pictures of installation diagrams and most have the return line up into the display, that will be a major pain....
Any advice?

kles · Feb 13, 2019

Iv got the 57 w it's running off the manifold and on the output side I run it though my chaeto reactor I'm working on then back into the sump . Yes its recirculating back but with the flow rate and being processed again i would thing better chance of a better sterilizing. I run a large unit in hopes of better results I know there no way of 100% clean system but anything helps

jent · Feb 13, 2019

Don't worry about the small amount of recirculation through the uv. The uv should be relatively low flow compared to the return to the tank (dwell time is critical). An extra pass might just help kill some harder to kill protozoa or something anyways.

Dr. Reef · Feb 13, 2019

Flow rate on uv has to be slow enough to make sure of contact time as things are flowing past the bulb. Most likely return flow is lot more than flow rate of the uv. I doubt there will be a whole lot of same water being treated over.

rockskimmerflow · Feb 13, 2019

Yes, as others said don't worry about the recirc. Also don't worry about the flow rate. It is critical, but on a 25W even you're unlikely to blow past it's max kill rate with bleed off from a vectra M1. Aquaultraviolet has a chart on their site showing flow rates for various levels of irradiation of the process water. You can put 400gph through that 25W and according to Aqua ultraviolet you will still be in the 90,000 microwatt per cubic cm range which is the max kill rate they list in their chart for near end of lamp life levels. You'd be hard pressed to get much more than 400gph through a manifold fed by an M1 and still have enough return flow to your tank.

Most important item for installing a UV which I see overlooked all the time - you need to orient it so the input and output are either horizontal or facing upwards. If mounted vertically, then the water must enter the lower inlet and exit the upper. This is to avoid a large air pocket around the bulb sleeve which severly reduces the UV's effectiveness and will heat the buld excessively. As long as it's oriented properly I think you'll have a nice insurance policy against many fish disease outbreaks or other nasty microalgal blooms. Best of luck!

slojmn · Feb 13, 2019

Okay, great. Sounds like I shouldn't have any problems with T'ing it off my return. Now to figure out where to mount it. I was not planning on it so it will be a bit challenging. Thank you very much for the tips on mounting.

slojmn · Feb 24, 2019

I installed the AquaUV sterilizer T'd off my return. The most flow I can get is about 240 GPH wide open, I've increased the Vectra M1 a couple notches up and that's the best I can get. Even with that, I am having some difficulty getting the sump and overflow dialed in. Its a pain. I have the output of the UV emptying into the chamber prior to the return pump chamber. If I ramp up Vectra M1 anymore it depletes the return compartment and if I open up the overflow line I get a lot of noise (just the way the overflow pipe into sump is designed. A bit of a pain. It might be easier to get a dedicated pump, any pump recommendations? Is the 240 gph way too low,? It seems so according to the chart in the manual which suggests 640 gph ish for my 100g tank plus sump.