Uv Sterilizer

[Noahs ark6]

hi, i'm getting a uv sterilizer but i'm not sure how long to have it on a day, is it all day or just a few hours, thanks

 

[fluttermoth]

I wouldn't bother using one at all; waste of electric IMO.

 

[Noahs ark6]

I wouldn't bother using one at all; waste of electric IMO.

ok, thanks

 

[TwoTankAmin17]

UV sterilizers can serve 3 different functions, each of which require different flow rates. There are two primary measurements involved. One is the contact time, that is how long the water is exposed to the UV - often referred to as the flow rate/watt of UV. The other is the turnover rate, that is how many times per hour the volume of the tank should pass through the UV unit. What one needs to determine is what size gph pump (powerhead or inline with a canister) one needs and what wattage UV bulb should be used.

The 3 potential uses of UV are found in the table below:

Flow Rate & Turnover Rate Table:

UV-C Use ----------------------- Flow Rate (generalized) --------- Turnover Rate

Clarification:
(Green water control; Aquarium/Pond)
Most popular application for ponds------40-50 gph per watt ------ Once per 2-3 hours

Level One Sterilization:
(Bacteria, some Virus)
Most common & recommended
aquarium application --------------------20-30 gph per watt --------1.5 times per hour

Level Two Sterilization:
(Parasites, "Stubborn" Viruses;
Recomend for Swimming Pools) --------8-10 gph per watt ---------Up to 4 times per hour
From UV Sterilization Basics

The best way to explain it is to use an example of 50 gallon tank. If you want clarification you would start with needing to turnover the water once every 2-3 hours. So divide 50 gals by 2 or 3 and it would mean you need a 17 - 25 gph flow . To determine how strong a UV bulb you would need for clarification use 40-50 gph/watt of UV bulb, so divide 17-25 by 40-50gph. This would require a bulb of under one watt- 17 gph divided by 40 to 50 = .425 - .625 watts and 25 gph would = .625 -.50 watts.

Now lets assume you wanted to achieve Level One Sterilization for the 50 gal. tank. This requires a 1.5 times/hour turnover rate which translates into a flow rate of 75 gph. However, now you need to reduce the flow rate to between 20 and 30 gph/watt. Dividing 75 by 20-30 gph means you would need a bulb between 3.75 and 2.5 watts.

Finally, if your goal is Level Two Sterilization then you want a 4 times/hour turnover rate or 200 gph. To get the proper UV wattage to achieve this, divide 200 gph by 8-10 gph/watt or a 20-25 watt UV bulb.

Basically the more things you want to kill, the higher the flow rate needed and the stronger the bulb that should be used.

Using the above guidelines I purchased a 5 watt UV unit to use on a 29 gal. tank to receive wild caught altum angels. It will be powered by an 80-100 gph powerhead or pump. That will result in a turnover of between 2.75 and 3.44 times/hour and give me a flow rate of 80/5w or 16gph and 100/5w or 20gph. That means I am at or over the Level Two (20-30 gph) but under Level Three (8-10 gph), Similarly my turnover rate would be above level One but below Level Two. However, when one accounts for the fact that no tank gets 100% filled and that they also contain decor etc, the actual gallons in my 29 is going to be closer to 25 and my nuimbers get much closer to Level Two.

Hope this helps.

Edit: Sorry, the table did not post as it appeared in the table on that site. I have tried to rearrange the layout to work.

 

[Fishy friend2]

i think they are mostly meant for pond they just get rid of single celled algae i think. i wanted one but they were pricey when i could just go and buy a bottle of algae killer.

 

[Aquamaniac]

I had a friend with one.I can tell that he had a very good experience with UV lighting.first i can't remember ever seing a tank with water so clear.Second it really helped him keep is discus sickness free.So my opinion is: Yes they are pricey.No we don't really need them. But for whoever can afford them they do make a difference.I was thinking about one for my tank. But i realised that at least for now i don't need it.And i still fear the effect of a UV sterilizer on a planted tank.

 

[Noahs ark6]

ive found one for £19.99UV sterilizer

 

[TwoTankAmin17]

If you would really like a tonof great information on UV, go here UV Sterilization Basics

 

[Aquamaniac]

ive found one for £19.99UV sterilizer

I've seen this UV sterilizer before.It is cheap but i reasearched about it before and aparently its quite hard to find the right UV bulbs when you need replacements.And even if it does the job the quality of it does not compare to the more expensive ones.

But i have bought from all pond solutions before and my experience with them is great.So maybe its not that bad.

 

[Noahs ark6]

thanks