use of UV sterilizer on reef tank

Thinking that most UV sized to kill waterborne bacteria will kill everything, even just waterborne, is alarmist.

In general, UV cannot kill enough ich to be effective to limit its spread. It cannot kill off most larger organisms to eliminate them in a tank.
 
Depends on who you talk to.

UV will kill most pathogens that are in the water column. It will kill them by scrambling their chromosomes. But only if the flow rate is slow enough to increase the dwell time, thereby increasing the UV dosage, and the intensity is large enough. With that said most aguarium UV's won't kill ich, copepods, pretty much anything bigger than mold spores. Your chances of killing some of these organisms increase as the flow rate decreases and the zap dosage increases. It will not totaly irradicate all these organisms. It will help though. It will help irradicate most algae spores in the water column. If your fish contract ick, and you want the UV to get rid of the ick, nothing short of running the fish through the sterilizer will get rid of the ick.(snark)

For the unit to work slow down the flow rate( don't buy most manufacturers claims of running a 25 watt sterilizer at 800 gph. The bad organisms will giggle and thank you for the free tan) I run mine at around 175 gph. Clean the quartz sleeve at least once a month. Change the bulb at least every six to seven months( especially if you run it 24/7 like I do).
 
You also have to consider that using a UV sterilizer will possible kill beneficial bacteria in the water column as well as any "potential" bad ones.
 
I have a 40 watt on my return side. It's a little insurance on free floating parasites. Once a month I turn it off for a copopod bloom, then turn it back on.
 
You also have to consider that using a UV sterilizer will possible kill beneficial bacteria in the water column as well as any "potential" bad ones.

I think you don't have to.

I think beneficial bacteria are not found waterborne in significant numbers.
 
UV units can help in some cases of greenwater, but they're useless against diseases and parasites the way they're run in our systems. It'd take a very large unit to do anything at all for controlling marine ich, which is a very large ciliate. Some people claim clearer water when using one, although it's not clear what they do.

Other than the electricity bill and perhaps the occasional accident, I don't think they do any harm.
 
I think they can be useful for a uronema, which is pretty rare as far as infecting fish. It is not something I would probably bother to run constantly. I have heard some use them to break things down to be skimmed out, I am unsure how effective that really is for that job.
 
UV units can help in some cases of greenwater, but they're useless against diseases and parasites the way they're run in our systems. It'd take a very large unit to do anything at all for controlling marine ich, which is a very large ciliate. Some people claim clearer water when using one, although it's not clear what they do.

Other than the electricity bill and perhaps the occasional accident, I don't think they do any harm.

IME, the common size UV is effective against waterborne bacteria, in much the way that it is effective against algae. It is not effective against ich.
 
I was actually looking into buying one yesterday, but my tank isn't really having problems. It's funny how there is a new thread on this topic. I'm only having slight green algae on my glass, and figured ti didn't hurt to get a UV sterilizer, but I guess from what you guys have been saying that it does very little for the price they cost.

So what should I do about the slight green glass algae?
not to hi-jack thread.
 
I was actually looking into buying one yesterday, but my tank isn't really having problems. It's funny how there is a new thread on this topic. I'm only having slight green algae on my glass, and figured ti didn't hurt to get a UV sterilizer, but I guess from what you guys have been saying that it does very little for the price they cost.

So what should I do about the slight green glass algae?
not to hi-jack thread.

IME, the UV is effective in reducing the incidents of external bacteria infection in fish, especially during stocking of new fish.

In a DT, it has an adjunct use in slowing the spread of algae.

If your interest is not in fish or only in a few small fish, you may not need a UV in a reef tank. Otherwise, for me, going without UV when stocking new fish is a little foolish. I will never stock fish without UV in QT for as much as possible, and I always use UV in DT within three or so months after introducing new livestock.

UV degrades many drugs so it cannot be used with such drugs. UV's role is limited but very important to me within the limit.
 
IME, the UV is effective in reducing the incidents of external bacteria infection in fish, especially during stocking of new fish.

In a DT, it is an adjunct use in slowing the spread of algae.

If your interest is not in fish or only in a few small fish, you may not need a UV. Otherwise, for me, going without UV when stocking new fish is a little foolish. I will never stock fish without UV in QT for as much as possible.

UV degrades many drugs so it cannot be used with such drugs. UV's role is limited but very important to me within the limit.

So i should run one on my QT tanks.
I have two QT tanks and run nothing on them, what UV should I get for a 29g and a 35g, my DT is a 90rr, with a 100g rubbermaid sump/55g refuge/frag tank.
 
So i should run one on my QT tanks.
I have two QT tanks and run nothing on them, what UV should I get for a 29g and a 35g, my DT is a 90rr, with a 100g rubbermaid sump/55g refuge/frag tank.

IME, UV when properly used is quite effective in reducing the incidents of external bacteria and viral infection. It is likely that drastically reducing waterborne patheogens enables the basic non-specific defense of fish to be adequate.

I always use UV in QT when I am eradicating ich. Not so much for the ich, but the always lurking patheogenic bacteria. Copper to treat ich is one of few drugs that is not affected by UV.

In sum, UV is effective in the prevention of extermal bacteria and viral infection. But once infection has taken hold and drug needs to be used, you have to stop the UV.

Figure 5-10 GPH for each watt of UV and a turnover of 1-2 for bacteria control. Size the higher end for QT and lower end for the DT. possibly one UV will do for both QT and DT. Many people run the UV far too fast.
 
IME, UV when properly used is quite effective in reducing the incidents of external bacteria and viral infection. It is likely that drastically reducing waterborne patheogens enables the basic non-specific defense of fish to be adequate.

I always use UV in QT when I am eradicating ich. Not so much for the ich, but the always lurking patheogenic bacteria. Copper to treat ich is one of few drugs that is not affected by UV.

In sum, UV is effective in the prevention of extermal bacteria and viral infection. But once infection has taken hold and drug needs to be used, you have to stop the UV.

Figure 5-10 GPH for each watt of UV and a turnover of 1-2 for bacteria control. Many people run the UV far too fast.

ok, so then what brand should I look into purchasing? how many wattage? Should I buy three? one for each tank? I am looking into make a large purchase of fish very soon.
 
ok, so then what brand should I look into purchasing? how many wattage? Should I buy three? one for each tank? I am looking into make a large purchase of fish very soon.

Other than the "quality" consideration, there are two kinds, straight and spiral.

I have used only the straight ones, although I have had a spiral one for months from ebay that I have not used yet. I may allow a somewhat higher flow for the spiral kind, I believe. I will know more about the spiral kind.

If you have more than one QT, you may have to get one for each.

But you can think if you can switch over every 10-12 hours. I guess is that you actually can without proportionately reducing effectiveness. The reason is that the objective is to drastically reduce waterborne patheogen concentration. The rate of kill in a UV certainly depends on the initial and steady state concentration of waterborne patheogen. When few patheogen are produced, using UV only 12 hours each day may already have most of the effectiveness, IMO.

If you have existing infection in one QT, you should rigorously separate the two QT's. But you should be using antibiotics for an existing infection anyway, and should not use UV regardless.

There are also hang-on and inline styles. I generally prefer the inline type.

There is also with or without quartz sleeve. I prefer WITH quartz sleeve.
 
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UV might be useful in handling waterborne diseases, and a quarantine tank could be small enough that a large UV unit might be effective, but I'm still a little skeptical. It'd take a unit with a high capacity to turn over enough properly-treated water to make much of a difference. I doubt that <b>display</b> tanks can be treated in any useful way with one, given the typical electrical budget.
 
UV might be useful in handling waterborne diseases, and a quarantine tank could be small enough that a large UV unit might be effective, but I'm still a little skeptical. It'd take a unit with a high capacity to turn over enough properly-treated water to make much of a difference. I doubt that <b>display</b> tanks can be treated in any useful way with one, given the typical electrical budget.

How is a 30 watt UV for a 150 gal DT out of electrical budget?

A 30 watt UV running at 150 GPH for a 150 gal DT is effective in very much reducing the waterborne bacteria concentration, IMO.
 
So you want to fight algae in the display (not green water) with UV?

There is some misinformation floating around here. UV will help with "green water", but it will do little to nothing to fight hair, film, or other common nusiance algaes. It may kill some free floating spores, but that's going to do all of nothing to fight algae that's already established in the tank.

Focus on nutrient removal/control. UV is NOT the way to fight algae (except green water).
 
Anything that does not require waterborne agent to spread, or when the waterborne agents are too large/tough to be affected by UV, will not be controlled by UV.

Otherwise UV will be useful in reducing the concentration of such agent.

Seems easy to understand.

One then can ask what is the point of drastically reducing the waterborne concentration of patheogenic bacteria. Well, fish has defense against agents even without previous exposure, but this capacity is very limited.

UV basically duplicates the dilution effect of the ocean in regard to agents that the UV kills, not ich but bacteria and viruses.
 
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