UV strerilizers and rays

[kendragon]

John, if you're mainly using it to clear the green so the filter can take over then you probably only need it once or twice. You do not need it long term (off and on). Having it installed and not using it is a maintenance headache. Seals go bad, slim coat build up in the quartz sleeve and as mentioned bulb life.
Many koi ponds when first started up can never clear because of the massive amount of water and sunlight. Wall algae (natural bio filter) could never seed because the dark water prevents/filters sunlight to the pond walls. UV reactors help zap the free floating single cell algae allowing the water to clear allowing plants and wall algae to grow which from that point on establishes a cycle. Most cases the UV is no longer needed. I know of one pond that when the UV light goes out the water would cloud up and that's because he is overstocked so the UV is a intergral part of his filter.
UV for disease is another story which I do not believe is your intent of this thread or is it?

 

[johno27]

Nope no disease worries. I may just run it for the water clarity, I will probably just keep an eye on my power bill and see if the cost is worth the effect. Not sure how much power the 40 watt unit uses but the ballast sure gets hot.

 

[Chasintail]

Watts is the measurement of how much electricity used per hour. Your light drawing 40 watts uses...40 watts per hour. Electric companies bill by kilowatt hour OR 1000 watts per hour. To equal 1kw, you would need to run the light for 25hrs.

Handy website for electrical usage calculator:
http://michaelbluejay.com/electricity/howmuch.html

 

[johno27]

Right on, I was just finding it hard to believe that this ballast is only drawing 40 watts and getting that hot.

 

[Chasintail]

Does the ballast give amp specs on it?

 

[johno27]

120 volts 60 hertz and .43 amps

 

[digginrays]

i use 57w on my 1100g.i did notice a diffrence in water quality when the bulbs burned out and when i replaced them with new.(i have 2 in series but only plug one in at a time)my other large tanks do not have uv and seems just as clear.

 

[T1KARMANN]

I would change the bulbs every 6 months if I run it 24/7 or not.

My tank is 99% clear of green water after 24 hours so I don't think I would need to run the uv 24/7 to keep the green water at bay.

Is there anything to suggest turning the bulbs on and off is bad for them or the ballast? That would be my main concern is wearing out the ballast or bulbs faster.

Edit: NM Ken answered my question while I was typing it

if you are waiting to see a problem then its already to late

what i can NEVER understand is if you have one why wouldnt you run it 24/7 you wouldnt have a air pump and only turn it on when your fish are at the top gasping for air

 

[Chasintail]

120 volts 60 hertz and .43 amps

That "should" be the rating for the whole thing. If I'm correct, your ballast is drawing next to nothing at roughly 8-10 watts.

 

[Zoodiver]

if you are waiting to see a problem then its already to late

what i can NEVER understand is if you have one why wouldnt you run it 24/7 you wouldnt have a air pump and only turn it on when your fish are at the top gasping for air

^^This.

If you have UV, run it all the time. It's hard on the bulbs to be kicking them on and off due to the heat stress you're putting them through.
Needing UV for water clarity could also mean you are just under filtered in the first place. UV needs CONTACT time, not a big pump moving tons of water. Run a minimal amount so it's being effective. I run just enough flow to keep the bulbs cool. Make sure to stay up on bulb changes and quartz sleeve changes as needed.