Okay, Let's Talk UV Filters

[sbash]

Hi Everybody,

This past year, I have been experimenting with the Aquafit Aquatics 24W UV filter. I bought it to treat a specific problem, and it worked very well. So now it is another excellent tool in my toolbox, well, plastic tool tub...

However, since it worked so well, I wonder about running UV full time on my 220.

So, here's the pickle:
This one is a 24W, but it is rated for tanks up to 120 Gallons, while the Coralife Turbo Twist 18W is rated for up to 250 gallons, yet the Aqueon QuietFlow 18W only rated for 150 gallons...

Any idea why the discrepancy?

 

[Journeyman]

It may depend on the re flow rate through the UV filter. I tried to do research on this a while back. I found that there is no real consensus on size. The more powerful the UV the less contact time it needs with the water. I supposed in theory you could go with a far lower power UV light with a really low flow.

 

[Lowell Lemon]

Hi Everybody,

This past year, I have been experimenting with the Aquafit Aquatics 24W UV filter. I bought it to treat a specific problem, and it worked very well. So now it is another excellent tool in my toolbox, well, plastic tool tub...

However, since it worked so well, I wonder about running UV full time on my 220.

So, here's the pickle:
This one is a 24W, but it is rated for tanks up to 120 Gallons, while the Coralife Turbo Twist 18W is rated for up to 250 gallons, yet the Aqueon QuietFlow 18W only rated for 150 gallons...

Any idea why the discrepancy?

Read the articles from American Aquarium Products on line. They are located in Oregon, US. They have some very helpful information on the subject.

 

[sbash]

It may depend on the re flow rate through the UV filter. I tried to do research on this a while back. I found that there is no real consensus on size. The more powerful the UV the less contact time it needs with the water. I supposed in theory you could go with a far lower power UV light with a really low flow.

This was my theory too. The pump on the Aquafit (24W) is only about 100GPH, when the Coralife 18W recommends 200 gph minimum - but the Coralife is designed to keep the water in there longer). So perhaps that makes all the difference too.

Read the articles from American Aquarium Products on line. They are located in Oregon, US. They have some very helpful information on the subject.

Thanks, I'll look into that.

 

[rkpetersen]

So many factors. Not just wattage, but bulb design, sleeve design, and flow rate all influence effectiveness. The ratings manufacturers give don't mean much, and in part they depend on what the 'rating' is designed to kill, which they rarely explicitly say. Bacteria are easier to kill than algae which are easier to kill than protozoans. So if a sterilizer is 'rated' for 300 gallons, that may be for suppression of an algae problem, and to handle a crypto outbreak might only be effective for a much smaller tank.

What you really want to see is a graph of flow rate on the x axis versus UVC energy output in microwatt-seconds/cm2 on the y-axis, for each sterilizer design and bulb combo. Then you can determine the flow rate that will work for what you're trying to kill. For example you mention the Turbo Twist 18W. The chart for that sterilizer will kill algae at a flow rate of 240 gph but for parasites it has to be much slower at 110 gph. And you still have to decide if that available flow rate is enough for the size of your tank.

 

[ca1ore]

Plus there’s really no standards for sizing - so the vendors just mostly make them up LOL

 

[sbash]

The chart for that sterilizer will kill algae at a flow rate of 240 gph but for parasites it has to be much slower at 110 gph. And you still have to decide if that available flow rate is enough for the size of your tank.

Interesting thanks. That last sentence is the kicker. With the UV filter runing 100 GPH, on a 50 gallon tank, it won't process ALL the water twice per hour, let alone on a 50 gallon sump with a 500 GPH turnover (those numbers are not real to my systems)... You see where I am going with this... lol...

Plus there’s really no standards for sizing - so the vendors just mostly make them up LOL

Yeah, lol, it seems that way...