UV Sterilizer

[jason sartain]

Has anyone ever used a cheap(Inexpensive) pond UV Sterilizer on there tank?I bought a 9 watt from HD for $59.00 (rated for ponds up to 300 gallons),it has no metal parts to rust and it seems to be built pretty well.For this price I could put 2 in series so I would have 18 watts total.Please let me know.

 

[mojo]

dawgdude is right - a UV sterilizer is a UV sterilizer. I'd be a little concerned that it's not safe for saltwater, but it'll likely be fine.

Also realize that the effectiveness of a UV sterilizer depends strictly on radiation received, in terms of strength (the wattage rating) and time (speed of water through the UV).

Most people severely undersize the UV needed for their tanks. The 18watts of UV would probably be enough for your 24g tank, assuming you have slow enough flow. There are ways to calculate the flow needed to kill off, say, Ich, if you're interested.

 

[jason sartain]

Here you go Charlie

dawgdude;396102 wrote: I have not. I guess as long as it puts off uv and your flow through is slow enough then it should work. Post a pic of the unit you bought.

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[jason sartain]

So what size is needed for a 500 gal system?

mojo;396108 wrote: dawgdude is right - a UV sterilizer is a UV sterilizer. I'd be a little concerned that it's not safe for saltwater, but it'll likely be fine.

Also realize that the effectiveness of a UV sterilizer depends strictly on radiation received, in terms of strength (the wattage rating) and time (speed of water through the UV).

Most people severely undersize the UV needed for their tanks. The 18watts of UV would probably be enough for your 24g tank, assuming you have slow enough flow. There are ways to calculate the flow needed to kill off, say, Ich, if you're interested.

 

[mojo]

jason sartain;396122 wrote: So what size is needed for a 500 gal system?

I have a 114w unit on my 800g system, although I feel it's severely underrated - my off-the cuff guess would be around 180watts for a 500g system.

Aquatic Ecosystems has the charts for what intensity/duration kills what pests. You have to match that intensity with flow and turnover for your system. I'll see if I can pull that chart.

 

[jason sartain]

Thanks,I'll look foward to it.

 

[jason sartain]

This one has some "fins" inside the tube with a quartz sleeve.They also sell bigger units,I just tried the cheap route first because I had a store credit.

 

[mojo]

Here's the chart from Aquatic Ecosystems:

http://www.aquaticeco.com/images/static/techtalk/UV_exposures.gif" alt="" />

Note that Ich is 336,000. I can't find the reference for my specific unit, but it gives the uWs/cm2 rating for a given flow rate. Let's say it's 500gph for 90,000 uWs/cm2 - that means I'd need to drop the flow to 500/4 = 125gph in order to kill Ich (I believe I arrived at 300gph through mine to be effective - I wish I could find the numbers).

Now, how much turnover you need in your system is still widely up to debate - we've only established the rate you need through your sterilizer. Would 125gph be enough to clean a 500g system in a reasonable amount of time? Maybe, maybe not.

Again - flow is everything. I'd be curious to know what the rating was on a 9w sterilizer. I just looked up an [IMG]http://www.marinedepot.com/ps_ViewItem.aspx?category=Aqua_UV_Ultraviolet_Sterilizer_8_to_10_Watt_UV_Sterilizers&vendor=Aqua_Ultraviolet&idProduct=AV2111&IdCategory=FIUVUUET&child=AV2113&tab=1&style=with%20wiper&size=8%20watt">8w sterilizer on Marine depot</a>, and they show a max flow rate of 70gph to reach 90,000 uw/cm2, or 17.5gph if you want to kill Ich.

I'm guessing the numbers will be the same for your 9w units. So find a way to slow down the flow rate to 17.5gph (or 35gph if you have two in series), and the water coming out will be Ich-free. I'm just not sure it'd cycle enough to kill the Ich in the system....

 

[mojo]

Ah - here's a better link showing required flow rates for different units:

 

[mojo]

I'm afraid so...

To put it in perspective, I push ~300gph through my 114w UV sterilizer, and that cost me ~$800. UV sterilizers do</em> work (there- I just ate my words from a year ago!), but you have to run them slow or have a big unit. There's no free lunch...

 

[skriz]

I have always said that UV doesn't work and is a complete waste of money. UV theoretically works, but the sterilizers commonly found for the hobby are garbage. They're entirely too weak and of poor quality. In order for UV to be remotely effective, it needs to be powerful and the flow must be correctly matched. You also have to keep it clean and replace the bulbs in a timely manner.

Emperor Aquatics make the best units. These are the only ones I would even consider putting on my tank. To do it right though, you have to spend a lot of cash, but at least you're getting something for your money.

When it comes to UV, you have to go big or go home!

 

[grouper therapy]

I run 57 watts on 300 gallons at around 50 gph. super slow. Occasionally I run it through 114 watts at the same rate

 

[jason sartain]

Thanks for the read,I guess a little UV is better than nothing at all??

mojo;396202 wrote: Here's the chart from Aquatic Ecosystems:

http://www.aquaticeco.com/images/static/techtalk/UV_exposures.gif" alt="" />

Note that Ich is 336,000. I can't find the reference for my specific unit, but it gives the uWs/cm2 rating for a given flow rate. Let's say it's 500gph for 90,000 uWs/cm2 - that means I'd need to drop the flow to 500/4 = 125gph in order to kill Ich (I believe I arrived at 300gph through mine to be effective - I wish I could find the numbers).

Now, how much turnover you need in your system is still widely up to debate - we've only established the rate you need through your sterilizer. Would 125gph be enough to clean a 500g system in a reasonable amount of time? Maybe, maybe not.

Again - flow is everything. I'd be curious to know what the rating was on a 9w sterilizer. I just looked up an [IMG]http://www.marinedepot.com/ps_ViewItem.aspx?category=Aqua_UV_Ultraviolet_Sterilizer_8_to_10_Watt_UV_Sterilizers&vendor=Aqua_Ultraviolet&idProduct=AV2111&IdCategory=FIUVUUET&child=AV2113&tab=1&style=with%20wiper&size=8%20watt">8w sterilizer on Marine depot</a>, and they show a max flow rate of 70gph to reach 90,000 uw/cm2, or 17.5gph if you want to kill Ich.

I'm guessing the numbers will be the same for your 9w units. So find a way to slow down the flow rate to 17.5gph (or 35gph if you have two in series), and the water coming out will be Ich-free. I'm just not sure it'd cycle enough to kill the Ich in the system....[/QUOTE]

 

[mojo]

jason sartain;396289 wrote: Thanks for the read,I guess a little UV is better than nothing at all??

I wouldn't say that... UV effectiveness is like lighting your reef tank. You can't expect a 10,000 watt bulb used for 1 second per day to be effective, anymore than you can expect a nightlight used for 23 hrs/day to be effective. I'd argue that the 9w UV sterilizers won't do any good on your system.

This is only my opinion, of course - you're welcome to use them either way.

 

[jason sartain]

Now that you put it that way,I think you're right.