# Plumbing Options For UV Sterilizer



## Elvin Pena (Nov 27, 2003)

Greetings all! Iâ€™m in the development phase of setting up a 150g tank but I have a quick question for you guys regarding filtration. Iâ€™m set on getting 2 Eheim 2080s and having them handle all of my mechanical and biological filtration. I donâ€™t want to use carbon with these units as I would like to leave them relatively undisturbed with the exception of occasional maintenance. I want to add an 18W UV sterilizer and was wondering if I should either:

a) Place the sterilizer at one of the outputs from one of the 2080s. Iâ€™d rather not do this as I plan to have Hydor ETH heaters at the outputs of both Eheim units.

b) Buy a small pump and use it exclusively for the sterilizer.

c) Recycle an old Magnum 350 I have lying around, fill it only with carbon (no mechanical filtration), and place the sterilizer at the output. I donâ€™t mind this option as Iâ€™ve always liked to use carbon in my tanks and this option affords me the opportunity. Still, it would be another piece of equipment to have to worry about.

d) None of the above! Hereâ€™s what Iâ€™d doâ€¦

If you guys had the option, what would you do?

Many thanks in advance for the help.


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## ajanin (Jul 24, 2008)

you want a slow flow to maximize the " kill" time.if the water is cleaned before exposure to the uv, the bulb will stay clean longer. i have a little powerhead with a prefilter feeding mine.


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## JWerner2 (Jul 7, 2008)

C!

You can then easily adjust the flow as well if you feel needed but I never have.

One thing is that I would still utilize it for mechanical filtration just to help that UV last longer.


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## Toby_H (Apr 15, 2005)

I vote C... should have made a poll 

I have several UV lights in use...Two of them are 18W lights powered by a Magnum 350 (as well as a 20W by a Mag 350)...

I use the micron cartridge in mine. This ensures only extremely clean water enters the UV light... it also becomes somewhat clogged quickly slowing the water flow down giving the UV better dwell/kill time. If you fill it with carbon just make sure you stock it so none gets shot into the UV light. It can/will scratch the quarts sleeve...


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## fishyfishyfishy (Dec 24, 2005)

Slow flow is relative to the size unit you have and the size tank it's on. Much depends on what you're looking to do with the UV as well. As a clarifier, you can have higher flow but to kill off parasites such as ich would require a slower flowrate through the same unit. At a minimum, a turnover of twice the tank volume per hour is genreally recommended to be effective against parasites.

Ideally, running the micron cartridge with the carbon would be the best way to run it. The clearer the water going to the UV, the more effective it will be. The downside is that as the cartridge and/or combination of carbon clogs as mentioned to you already, flow will slow down. At that point, yes, your dwell/kill time does go up, but if it's at the expense of not turning over the tank volume enough, you are greatly diminishing it's effectiveness. An outbreak would be able to multiply faster than your UV is capable of killing and controlling it.

So, really you need to look at the ratings of your UV and determine what kind of flow you'll want through it for what you hope to accomplish with it. Then you have to determine if the Magnum will be able to continually provide you with that flow either before or after it clogs.

Personally though, I'd go with choice B. With it's own small pump you can establish a steady and constant flowrate through the UV that will not vary.


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## Elvin Pena (Nov 27, 2003)

I've always used carbon to have crystal clear water. This would be my first sterilizer. Would I even need carbon in that case? I want to use it primarily to keep my water clear, but like that fact that it will sanitize my water as well. I guess the million dollar question is... if you have a sterilizer, is carbon even necessary?


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## ccrider (Sep 5, 2008)

the carbon will remove dissolved solids and impurities from your water and the uv is a sterilizer like stated above. they have 2 different uses


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## JWerner2 (Jul 7, 2008)

Also if you go with C you probably wont need both of those other canisters.

Just one of them and the Mag.


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## Toby_H (Apr 15, 2005)

I've read that UV lights can bind extremely small particles together... allowing them to be picked up by fine media... I can't say 100% this is true but I have been using UV lights for several years and have consistently found them to make clean water into crystal clear.

I use the micron cartridge in my Mag 350s to push water through UV lights... I have also explored enough to prove to myself that the UV light / micron cartridge combo makes the water 'more crystal clear' than either unit alone...

Carbon requires being changed very frequently. This is the foremost reason I do not use carbon. I would speculate that the carbon & UV will work a little better than the UV without the carbon... but I doubt it would make enough of an improvement to justify the expense and maintenance involved...

I believe that the micron cartridge will give as much of a benefit as the carbon, but with less maintenance. Although the flow rate is reduced to around 150 gph... I only clean my Magnum canisters w/ micron cratridges once every 2~4 months... depending on the set up (the cleaner the overall set up the less I service the Canister).


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## Elvin Pena (Nov 27, 2003)

Thank you for the great replies! I think Iâ€™ll bump up the sterilizer to a 40W unit. I narrowed it down to the Ultralife ULTRAV40 (though I'm open to suggestions on this front as well). Iâ€™ll forgo the carbon and see how the Magnum does with the micron cartridge alone.


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## fishyfishyfishy (Dec 24, 2005)

I use carbon 24/7 in my tanks, but I wouldn't use it in a canister mostly because it slows down the flow too much. With my sumps, it's easy enough to replace a bag as needed and it doesn't interupt flow.

I'd be more concerned with maintaining flow then using both. If you do lots of partials on a regular basis, you can really get by without the carbon. I do partials about once a month so the carbon is a plus. I'll tell you though, I'm always amazed how clear I think my tank is until I put carbon in and it gets that much clearer.

Getting back to the flow though, good move on going bigger on the UV. Just watch out that you move enough water through it for it to be effective. Toby_H mentioned a 150gph flowrate with his Magnum. Add carbon and that will slow down even more...and even more so as the carbon starts to clog as well.

I'm sure your 40watt UV will be effective against parasites at only 150gph, but your tank is 150g. At a minimum, you'd want a flow of 300gph through the UV to be effective against parasites. Otherwise, they can multiply faster than you'll be killing them.

If you can get 150gph through a dirty cartridge, it still might be ok. It's not the 2 turns per hour through the UV, but that would at least be at what some consider to be the bare minimum for a UV.

Still though, I'd go with the separate pump idea to keep a higher, steady and controlled flow through the UV.


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## Elvin Pena (Nov 27, 2003)

The Magnum 350 is actually rated at 350gph. Granted once media is added that should cut the flow, but I think it should still do the job. As I mentioned I'm a big fan of carbon and have had much success with it in the past when replacing it regularly (every 2 months). I just figured there would be a way to get around it for this project as this would be my largest tank to date and I want to minimize the upkeep.


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## fishyfishyfishy (Dec 24, 2005)

Yah, I was going by the other posters reported flow. Once you have it up and running you can see what kind of flow you're getting. Mainly, the thing to remember with UV Sterilizers is that above all, proper flow is the most important.


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## Toby_H (Apr 15, 2005)

*** done some tests with my Magnum canisters (and others as well)... I find that with new standard media canisters in general actually perform at about 50% the rated capacity... a little less than that with the micron cartridge... With a flow meter, my Magnum 350 (gph) with a recently cleaned (but not brand new) micron cartridge moves 150 gph...

For my UV lights I use a formula of 1W UV power per 10 US gallons of tank volume...
@ 10 gph per 1 W of UV power...

This is turning the tanks voloume over 1x per hour... I have used this formula on several Blue Dempsey tanks to keep them alive through their 'parasitic vulnerability' stage.

fishyfishyfishy gives great UV advice, this is one of the few areas we disagree...


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## fishyfishyfishy (Dec 24, 2005)

I'm not in total disagreement....1 turn per hour is OK, it's just at the bare minimum of being acceptable. If you're hovering around there with a clean filter, it's likely that you may fall below even that as it clogs so I'd shoot for higher.

On a 150, a turn of 1.5 times per hour or 225gph through the UV would be better than 150gph. 300gph would be really nice.

Of course this is not scientific and I have no way to verify any of it. But, that's pretty much the most consistant advice I've read about over the years.

For my own units, I didn't apply a specific formula like that. Mine are all plumbed on the return lines from my sumps so they get very high and consistant flow. So, for example on my 450g I have a flow of about 2500gph on my return line and just bought a unit that was effective against parasites at that flowrate. The actual turnover wasn't really a consideration since at 2500gph I already knew I had a turnover of 5-6 times per hour so it was just a matter of matching a UV to the flow. The drawback to plumbing them in-line like that is the need for higher wattage units, but even with my 24/7 carbon they make a difference.


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## Notrevo (May 2, 2005)

Using the formula that Toby_H put forth I am looking at (roughly) a 53W unit and then 530GPH or 1100GPH as suggested by fishyfishyfishy...roughly. I am looking into the UV application myself more so for clarification than parasite control...though of course the dual benefit is great. Looking at the posts here just about all have some type of "pre-filter" if you will. I would need another 2262 with just floss to support my aquarium or a DIY with outboard pump/pre-filter configuration. Does anyone have any pictures of their setup I/we could review?


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