# UV Sterilizers



## Ohio Cichlid Lover (Feb 27, 2012)

My biggest tank is a 55 gallon. I have New World Cichlids in it. I have plenty of filtration but was wondering if anyone uses UV sterilization in their tanks. Is it a necessity or just something that may or may not help? My water specs are really good most of the time (im a little overstocked at the moment). I always do my frequent water changes and substrate cleaning. Would the benefit of the UV out weigh the cost?

Thanks for any advice

Van


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## jd lover (Mar 11, 2011)

I don't remember where I read this and how true it is but I do recall reading that in order for UV sterilizer to work the water must be move through it slow enough that the light has a chance to come in contact with it. I think I read that its about 15gph.

Like said I don't know how true this is


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## cantrell00 (Oct 30, 2010)

jd lover said:


> I don't remember where I read this and how true it is but I do recall reading that in order for UV sterilizer to work the water must be move through it slow enough that the light has a chance to come in contact with it. I think I read that its about 15gph.
> 
> Like said I don't know how true this is


Varies on what you are trying to eradicate... I think I recall parasites being zapped @ 30 GPH, some forms of bacteria around 50-60 & free floating algae @ around 100 GPH.

I can vouch for the algae being removed at that flow rate because I had to deply one on my 180. As for the other two, I don't know. I can say that I have not had any problems with parasites or infections since I started using my UV though. It could be purely coincidental though...


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## jd lover (Mar 11, 2011)

i dont run any on any of my tanks and so far no problem lol but then again clean water should fix 90% of the problems hobbyist encounters. just keep up with the water change and you wont need the unnecessary knick knacks


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## Ohio Cichlid Lover (Feb 27, 2012)

Ok...thanks very much for your input.

Greatly Appreciated!

Van


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## cantrell00 (Oct 30, 2010)

jd lover said:


> i dont run any on any of my tanks and so far no problem lol but then again clean water should fix 90% of the problems hobbyist encounters. just keep up with the water change and you wont need the unnecessary knick knacks


I had to because of tank being exposed to direct sunlight. A UV was the only way to combat the green water.

They can be a great preventive measure for parasites though...


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## jd lover (Mar 11, 2011)

ah none of mine are in direct sunlight just nest to windows lol.

it can be a great preventive but like everything else it has to be set up properly and as said the water needs to be flowing pretty slow for it to be effective and lots of hobbyist aims for around 10x turnover i believe. so that might be too much flow to make these effective


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## cantrell00 (Oct 30, 2010)

No... They have to run really slow so the water (along with the bacteria, bugs and/or algae) can be exposed to the UV long enough to be effective..

When I first set mine up, it took about a week @ 100 GPH before I could see an improvement. Moving the tank or blocking the sunlight was not an option for me...

The only way UV's are effective is if they are ran constantly @ low flow rates. They eventaully catch up and perform surprisingly well at combatting algae. My tank water has never been so clear and I ran a ton of filtration prior to adding the UV...


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## jd lover (Mar 11, 2011)

That's what I'm saying most hobbyist aims for 10x turn over with filtration which is too fast to make the UV effective. Unless you're running it on a 10g tank


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## cantrell00 (Oct 30, 2010)

Mine is ran on a seperate micro pump in my sump... It isn't fed in the flow of the main filtration. It is it's seperate system... The only way to run them effectivel in my opinion... My normal filtration is running @ 1200-1300 GPH.


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## 13razorbackfan (Sep 28, 2011)

cantrell00 said:


> No... They have to run really slow so the water (along with the bacteria, bugs and/or algae) can be exposed to the UV long enough to be effective..
> 
> When I first set mine up, it took about a week @ 100 GPH before I could see an improvement. Moving the tank or blocking the sunlight was not an option for me...
> 
> The only way UV's are effective is if they are ran constantly @ low flow rates. They eventaully catch up and perform surprisingly well at combatting algae. My tank water has never been so clear and I ran a ton of filtration prior to adding the UV...


I have read that UV sterilizers are effecting at killing free floating algae spores at 1000gph using a 8w bulb in 1500 gallons of water....for freshwater tanks. Salt is a bit different. To kill free floating and free swimming stage parasite using a 8w bulb the max flow is 642gph in a tank up to 200g.

http://www.aquaultraviolet.com/sites/de ... 0Water.pdf


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## 13razorbackfan (Sep 28, 2011)

13razorbackfan said:


> cantrell00 said:
> 
> 
> > No... They have to run really slow so the water (along with the bacteria, bugs and/or algae) can be exposed to the UV long enough to be effective..
> ...


Is the above correct? I had another user from another forum point me to the link above and explained to me that using the formula uw/cm2 would determine the amount of contact time needed to kill free floating or free swimming parasites. The science is WAY over my head to say the least.


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## cantrell00 (Oct 30, 2010)

I dunno man.. I was using the instructions that were packed with the Coralife turbo twist that I have.. I would think that they are using some equation as a reference also, right?

Over my head too.


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## 13razorbackfan (Sep 28, 2011)

cantrell00 said:


> I dunno man.. I was using the instructions that were packed with the Coralife turbo twist that I have.. I would think that they are using some equation as a reference also, right?
> 
> Over my head too.


Yeah....the only reference I can find that breaks it down with the proper equation is the link listed above. I was reading another forum and a marine biologist is the one that told me that the GPH would be quite a bit higher than what I previously thought(9w 125gph or somewhere thereabouts). He said it would be about quadruple that in freshwater only and lower in saltwater. So I started searching and that is the only link I could find with a breakdown using the formula he told me to look for which was uw/cm2. I did find the reference to the other numbers but they were just typed into a message board such as this one. So I have no idea.

If anybody knows FOR SURE and has a link to hard data then I would really love to review it as this has bugged me for years going back to my saltwater days. Any help here would be appreciated.


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## cantrell00 (Oct 30, 2010)

The referenceI have very may well have been for saltwater. The lady I bought it from had it on a reef tank. She sold me the pump also.. You very well could be right...


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## 13razorbackfan (Sep 28, 2011)

cantrell00 said:


> The referenceI have very may well have been for saltwater. The lady I bought it from had it on a reef tank. She sold me the pump also.. You very well could be right...


LOL....I have no idea if I am or not that is why I was hoping for another member to post a good reference with data. I have always wanted to know the true GPH flow rate for freshwater sterilizers to kill both algae spores and free swimming parasites.


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## GTZ (Apr 21, 2010)

Some information that I came across. It's a tricky concept to grasp, or at least it was for me. I have done my best to ensure there are no errors. I'm happy to make any changes.

*Clarification*; (Green water control; Aquarium/Pond) - *Flow Rate* = 40-50 gph per watt - *Turnover Rate* = Once per 2-3 hours
*Level One Sterilization*; (Bacteria, some Virus) - *Flow Rate* = 20-30 gph per watt - *Turnover Rate* = 1.5 times per hour
*Level Two Sterilization*; (Parasites, "Stubborn" Viruses) - *Flow Rate* = Under 8 gph per watt - *Turnover Rate* = Up to 4 times per hour

To use the Coralife Turbo Twist 6x as an example:
According to their information, at 500gph it is effective at eliminating simple bacteria. I'm going to disregard the fact that they regard bacteria as easier to eradicate than algae. They could be right, this isn't part of my research.
At 27.7 gph per watt (500gph ÷ 18watts), and a turnover rate of once per 3 hours, you're left with a max tank size of 1500 gallons (3 x 500 gallons). Note that this size is only for Clarification (high flow rate).
For Level 2 Sterilization, Coral lists gph as 110gph. At 6.1 gph per watt (110gph ÷ 18watts), and a turnover rate of 4x per hour, you're left with a max size of 27.5 gallons.
Look at the last example another way. You're trying to determine the correct wattage required for a 100 gallon tank, running at Level Two Sterilization; if you had a 100 gallon tank that needed to be turned over 4x an hour, you would need to turn over 400gph. At the required 8 gph per watt, you would need a 50 watt UV sterlilzer, or two 25 watt sterilizers.


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