UV Setup -

[mtreef]

Eric, I am no expert on the subject, but have done some research and have a comment... I have found that the UV makers overstate the max rating. The effective rating is much less. For example, I have a custom sealife 36W double helix that is rated to 500gph max, but has to be run at around 375 gph to kill parasites.

I gave up on running the UV in-line with the return pump and just ordered a small pump. I am going to pull from my sump and return back to the sump. That way I can better control the rate of input to the UV.

good luck!

 

[ericwest]

The UV is a 25watt Aqua Ultraviolet. This is used on a 150g "Fish Only" with live rock, sand, and the usual "janitor crew". Only corals are gorgonians. 10 small to medium fish are currently in the tank.

I would like to know if I have the UV setup correctly and efficiently. I question the systems current setup due to excessive cyanobacteria growth, even though this is a new system (5 months old) that experiences monthly fish additions, as well as an early wipe-out due to a heater cracking.

Currently, the UV is mounted vertically, with the internal transformer on top. The external main circulation pump is plumbed so that the tank return line is T'd off, which feeds the line to the lower intake of the UV sterilizer. This line has a dedicated ball valve to control the flow, which must be turned about half way to keep the UV from leaking at the seams (where the transformer screws into the main body of the UV). I believe this is due to the pressure created from the high amount of flow (pump is an Iwaki 30rlxt), even though this particular UV is rated at 1000 gph.

The return from the UV goes directly back into the sump, near the pump return intake.
Thus, should I try to get more or less flow through the UV? Should I plumb the UV off the tank-to-sump return rather than the sump-to-tank return (gravity fed)?

Any suggestions and experiences with UV sterilizers are greatly appreciated.

Thanks,
Eric West