# UV Filters



## baka (Jan 4, 2006)

Hi,

Do you need a high flow cannister filter to use a UV Filter?

Thanks


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## eklikewhoa (Jul 24, 2006)

You need a canister with a flow rate that can handle the uv and vice versa.


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## baka (Jan 4, 2006)

is it recomended to use one? and how important is it to a tank


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## eklikewhoa (Jul 24, 2006)

I hear rave reviews about them and I have made it a point to get one someday but I have never owned one and read of lots of disease/algae even with them that I have yet to experience myself.


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## Melbourne (Sep 27, 2004)

baka said:


> Hi,
> 
> Do you need a high flow cannister filter to use a UV Filter?
> 
> Thanks


UV's need to run at the proper flow rate to remove waterborne algae, etc. If you are running it for parasites, etc. you will need to run it at a even lower flow rate. For example on my Turbo Twist 36w - I have to run it around 290 gph to be effective for parasite control. Bear in mind UV's can only effect certain free swimming stages of certain parasites but are great at nuking green water. Check with the UV manufacturer to determine the proper flow rate(s).


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## Laith (Sep 4, 2004)

baka said:


> is it recomended to use one? and how important is it to a tank


I've never used one. Never found that I needed one so I avoid adding another piece of equipment to my tanks.


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## yxberia (Apr 19, 2005)

Moderate flow is prefered. But from my experience, the flow does not affect the efficiency much. I have 11 watt and 9 watt UV both with 1200 l/h filtration, they work just fine.


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## jon_the_newb (Dec 30, 2006)

Flow rate would seem to be based on what you want to kill. Green water algae dies easier than some water based pathogens, like ich. The slower the flow rate, the more time the water and whatever it is you want to kill, stay in the UV Sterilizer. The longer time it has to be in contact the greater the kill rate of whatever it is.

I wouldn't recommend one though, unless you have something specific you're looking to kill, like green water.


Jon


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## Mad Dog (Mar 3, 2007)

> Moderate flow is prefered. But from my experience, the flow does not affect the efficiency much





> Flow rate would seem to be based on what you want to kill


Sorry to disagree here, but the flow rate is pretty important to the effectivness of a UV filter...and each one is rated for a specific amount of water to run through it on an hourly basis in order to have the best results. The bottom line is that depending on the wattage, chamber size, and options such as the twisting versions, the amount of time that the water, and hence the items you would want the UV to kill, is exposed to the UV light, the better the results will be. From what I have heard and IME, it is best to get a UV filter which can and will allow for nearly three times the tank's volume to be exposed to the light per hour. Obviously, this gets harder as the tank gets bigger, but there are some pretty big versions available.

For myself, I use a 9 and 18 watt UV filter on my saltwater tanks and I simply bought another small submersable pump to create a closed loop system. In my area, I can buy a 300 gph pump for around 20 dollars so it is not something that is going to break the bank or anything that.

However, there are tons of arguments one can make as to if a UV is worth the price and subsequent electric costs, if they can really kill every thing you want to remove, and if they are actually more damaging to the benificial aspects of things living in your tank that get mixed in with the bad things passing through the light. Obviously light is not selective in its killing capability and so this is something to consider as well. For most aspects, this is something that would affect a saltwater tank more so than a freshwater one...however, most people wouldnt even think about using UV on a FW tank. There are many many ways to deal with issues in freshwater which do not include UV light, or even meds/chemicals/commercial products. This is my opinion as well, however like i said, I am using them on my salty tanks and I am 100% sure that they work pretty much as I expected and I have even kept one fish which had Ich in my main tank without it spreading to other fish...however, FW ich and Marine Ich are two totally different things and the argument can be made that FW ich is harder to kiill than the marine version.


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## LilLou (Apr 23, 2006)

Ever since a bout of green water I have had a UV on my tank.


On my existing tank I have an 18W UV running on the outlet side of my 2028 Eheim.

On my new tank I plan to have a 36W UV with a separate pump to push 300 GPH through and back into the sump. UV manufacturer suggested 100 - 600 GPH 

Lou


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## Mad Dog (Mar 3, 2007)

LilLou said:


> Ever since a bout of green water I have had a UV on my tank.
> 
> On my existing tank I have an 18W UV running on the outlet side of my 2028 Eheim.
> 
> ...


With the higher wattages, you can force more water through the UV and still have the same effects...this is the benifit to those units, such as the one you plan to use on your new tank. My 9 watt 'turbo twist' is also rated at 100 to 300 gallons per hour and I actually do somewhat of the opposite and run 80 gph through it normally. This is on a saltwater tank though and so the slower, the better. I also do not have to worry about the UV light having a heating effect on that tank as far as running the water through it slower than is recommended. The tank overheats itself anyways and so a chiller is in the works...right now, I have an intricate system of fans all plugged in to four outlets, which I am sure is a nice fire hazzard but my only option right now


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## jon_the_newb (Dec 30, 2006)

> Flow rate would seem to be based on what you want to kill





Mad Dog said:


> Sorry to disagree here, but the flow rate is pretty important to the effectivness of a UV filter...


I'm not sure why you quoted me, and then said you disagree. From the read of your post, we do agree. From looking at the manual to my Turbotwist 18W, a flowrate of 110gph should kill parasites, 240gph should kill free floating algae, and 500gph should kill bacteria. So.. Based on what you want to kill, say GW, you'd aim for 240gph, or less, _for this unit_. For a larger unit it would stand to reason that a higher gph would be acceptable.

Jon


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