# UV Sterilizer Questions



## euRasian32

I figured this was the best place to post these questions about UV Sterilizers.

I have a 125 gallon (freshwater) and I plan to run a UV Sterilizer.

I've read that 8-9watts is good for aquariums up to 125gallons, but each company varies (a little).

Is a 15 watt or 25 watt unit overkill?

If you got a 15 watt unit could you later replace the 15w bulb with a 25w? (Coralife has ONE unit that comes w/ a 10w bulb, and they offer higher watt bulbs, I'm assuming that they fit the ONE unit they offer.)

What would be a good one to go with? Recommendations?

Here's some of the Sterilizers offered in my current catalog that fit my price range, I figured I'd start my shopping around on the forum:

Current
15w for 119.99
25w for 129.99

Coralife
10w for 99.99
15w bulb for 17.79
25w bulb for 22.89

Others don't offer more than a 5w unit, and some are over 150 *******.

TIA, Charlie


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## TheOldSalt

Bigger is better. There is no overkill. 
There is, however, underkill.
Get the 25w if you want actual results you can see. A smaller unit can work too...eventually.


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## euRasian32

Thanks OldSalt, 

Couple more questions:
Does the Sterilizer unit impede the flow of water? I plan on having 2 Fluval 404's. 1 mechanical and chemical media, and the other strictly biological... I was going to put the sterilizer in-line of the in-flow to the 404 w/bio media.

Saw the other thread where you were very helpful. You recommended the Turbo Twist model. I've read that it does 2 complete passes along the length of the lamp, resulting in 98% sterilization.
Is this the sterilizer you use? What other brands would you recommend besides the Turbo Twist?

I've decided to go with the 25w, which is more than enough for a 125 going by what I've read. At this point, money isn't an issue anymore, but I would like to keep in under 200.

C


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## Damon

Yes it will impede the flow of water, a little. Also UV is not recommended long term if you are planting the tank.


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## euRasian32

Thanks simpte, i thought it would at least a little. No desire for plants, I want to go w/FW stingrays (motoros) so I'm keeping the bottom free, I may add a floatable piece of driftwood w/ Java Moss, but the rays are a priority.

So... Would it be a bad idea to put the sterilizer in-line of the inlet tube to the Fluval 404? or would it be better to put it on the out-flow? If the out-flow is a better option I'd opt to put it on the 404 w/mechanical and chemical filtration.


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## TheOldSalt

It's generally never a good idea to put anything on the intake side of anything, since that can create cavitation. Pumps should push, not pull.

The UV's I used to use most were really big 64 watters, 5 feet long, with 3-inch radius contact chambers. They don't make those anymore as far as I can tell, although I think that Aquanetics has something similar. As for a smaller unit, I think the turbo twist is a very nice design.


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## euRasian32

thanks again, I have more anal retentive questions (numbered)

I'm going to take into consideration what you've stated, however, with the design and placement of the filter I'm probably going to put it on the inlet and wing it. Both the 404's will be under the tank. If I put the sterilizer on the outflow it has to not only go through the sterilizer, it has a 3' head that the water needs to travel also. 

The inlet will have the gravity advantage with a 3' drop. I want the water that passes through the 404 w/ biological media to be sterilized. The 404/bio filter is my main concern.

I've read that the Turbo Twist UV, with spiral design creating 2 complete passes over the length of the lamp, eliminates 98% of micro-organisms. A sterilizer using a quartz sleeve eliminates 99.9% of micro-organisms. 1) Can you replace a regular UV bulb with a quartz sleeve bulb?

I couldn't find an actual sterilizer unit for Aquanetics, just replacement bulbs.

I noticed that Aqua Ultraviolet sterilizers have ###gph in the specs. Example: the 25w unit says 1200gph. It obviously does not come w/pump. 2a)Does the gph in the specs reflect the amount of water it sterilizes per hour? 2b) or do I need a 1200gph pump to run the sterilizer efficiently?

TIA


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## TheOldSalt

No. The slower you run it, the better it works.
The flow rate is the maximun rate at which the UV might be able to kill, but that is at absolute MINIMUM effectiveness.

Protecting your media is all fine and dandy, but 
1-your canister filters should never be depended upon so much for biofiltration
2-the filter will keep the UV cleaner and working longer and better
3-the head is fine, since it slows the water and results in a better kill.

I tend to doubt that you can change bulb/sleeve types in one unit, since UV units are designed to work with one kind. The sleeve itself is not the bulb, but the jacket around the bulb which actually contacts the water. The bulb stays dry. The airspace between the bulb and the sleeve heats up to around 100F, which affects the UV wavelength penetration into the water, which makes it more deadly.


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## phoenix_princess

Why not just "T" off you line with a ball valve, Old Salt is correct in that the longer the residence time of the water in the UV steralizer the more efficient it works. If you "T" off then you do not have to worry about impeding your flow. In essence you would be augmenting your filtration. I am not sure there is a "UV" unit out there rated high enough to be a straight in line and work efficiently.
The Turbo Twist is probably the better unit since the exposure time would be greater.


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## euRasian32

Jolly good

Thanks OldSalt - you've been a great help. I saw another thread about UV Sterilizers where you helped too, there's good info in there too.

phoenix princess: would you mind going into detail about the T w/ball valve? I'm assuming that you mean T'ing off the outflow tube, 1 to the sterilizer and 1 to the return hose, and the ball valve would be for what? Hopefully you don't mind elaborating so i can get a better picture of what you mean. I partially understand the concept, i just can't visualize the placement of the T and the sterilizer at the moment. TIA

Charlie


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## euRasian32

I figured out the T diagram, but have one last UV question...

Will a UVS kill the good/nitrifying bacteria?


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## euRasian32

TheOldSat: Where's the Guru when I need him?


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## euRasian32

Found the answer to my question at pondsolutions.com


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## Fishfirst

it will if its in the water column... fortunately, your bacteria is usually in the substraite and filter media


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## euRasian32

Well I got one, and it's waaaaayyyy too big. There were differences in the descriptions on the webpages opposed to what's on the box. I'm going to return it for a smaller unit.

I got the TurboTwist 12x - 36w. It's over a foot long and six inches in diam. The webpages said I'd need min. 400gph and max. 1200gph pump or power head. The box stated min. 1000gph and max. 2200gph. Going to get the 6x - 18w.

C


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