Help with selecting UV sterilizer.

[james3586]

I have a 144 gal half round Oceanic aquarium.I need help selecting a UV sterilizer. I have been looking at the Gamma UV by Current. Is this a good sterilizer? I'm confused about how many watts I need. Dr. Foster and Smith says that the 25 watt Gamma has max 500 gal where as Current says 25 watt is 125 gall max. I am sure Current is correct because its their product. Do Ineed to factor in how much live rock I have do to the fact that this lowers how many gallons in my tank? I have 180 pounds of live rock in my 144 gal tank should this be a factor in choosing how many watts I need for my aquarium. HELP please!!!

[DaveK]

Welcome to RAG!

My personal choice for UV on a reef system is "none of the above". I don't feel that UV offers enough benifits to make it worth using.

That being said, the questions become -
1) Have you done your "homework" to the point where you have an understanding of UV and how it can be used in SW systems?
2) Why do you want to use UV?
3) What do you expect it to do for your system?

There are some areas where UV is of some advantage. One area where I might consider it would be to keep down algae living in the water colunm. Another area might be to keep the water clear by killing of any plankton in the water, although this is usually not a good idea in a reef tank. That plankton is all food for something else.

To be effective in disease control, you need a tremendous amount of UV, much more than you will get out of most of the "hobby size" units being sold. If your idea is to install UV to control the various parasites, I'd say forget it unless you are prepared to get a really hugh unit.

UV can only work on water that flows through the unit. (Yes, I know I'm stateing the very obvious, but some people seem to think you hook up UV and all your problems are solved) This means UV will not do much to stop nussiance algaes from growing in the tank.

UV must also be plumbed correctly. You want a rather slow flow of water through the UV unit. You also want the water as clean as possible before it goes thgough th UV unit. This usually means you branch off your main return, and run only part of the water through the UV unit.

The reasons you see such a spread in the size of tanks a given UV unit will handle is because it depends on what you are trying to do with the UV. Algae, being a single cell plant, usually takes less UV to kill it than an ich parasite would. I would consider the estimate by "the Drs" to be "extremely optimistic" at best.

That will give you a little background in UV. Now go back, do your research, and answer the questions, and we'll see if UV is something you should put on your system.

[DaveK]

I've made this thread sticky. UV is a topic that comes up often enough to need a thread of general information on the subject. Please post you own feelings about UV, good or bad.

[james3586]

I'm mainly going to use the UV on a timer to come on maybe 4 or so hours a day to control microorganisms including rapid-spreading diseases. So your saying for exampal a 25 watt Gamma Current could'nt handle any disease spreading organisms on 144 gal as they claim? Would it help do anything helpful for my tank? Thanks for your respons

[DaveK]

My advice would be to save your money, and spend it on something that is going to do some good. No, a 25w UV unit would not come close to being able to control diseases. I am assumeing that the diseases you want to control are Ich (Cryptocaryon irritans) and velvet (Oodinium ocellatum).

There are people that use UV and strongly believe in it. After trying it several times, over the years, I have not seen any big advantage to using it. In a home reef, I think it has little to offer. It's a bit different for a store system. Properly installed and maintained, it can help to stop the spread of disease between tanks. However, this only happens if everything else is done right. This is something very rare at a lot of LFS's today.

If you want to find out more about UV, get a copy of the book Aquatic Systems Engineering by P.R.Escobal. The book goes into a lot more detail about UV, and how to size and use it.
For disease control, invest in a QT tank and always use it, for fish and inverts you want to add. Once you have a QT tank, maintaining high water quality, and not over crowding the livestock will just about prevent disease problems.

While we are on the subject of disease control, never ever medicate a reef tank. No matter what the label says, no matter what the store tells you, there are no "reef safe" medications. Remember, unlike medications for people, that much be proven to be safe and effective, there is no standard for reef medications. Anyone can make any claim, and most of the claims are questionable.

[james3586]

Thanks for your help DaveK.

[Richard Riedel]

I have an 125g tank with a tetra 7watt uv running full-time. My goal was to reduce alge blooms and clear up the water. I can't say that I noticed any change in water quality and may remove it. I can say that last week I started using Chemi Pure and that has made a HUGE change in water quality. Hope this helps.

[MDPinUSA]

In order for a UV to function properly, you must:

1) Have a quartz sleeve, This is a tube that goes around the lamp.

This allows the UV lamp to get to the proper operating temperature of 108F.

If aquarium water is allowed to come in contact with the lamp, it cannot work as expected.

If glass or teflon used instead of a quartz sleeve, the UV lamps rays will not penetrate the system water as required.

2) It is essential to have the proper amount of system water pass by a UV tube.

We found 24 watts at 150 gph, on a 200 gallon aquarium.

3) UV lamps last about 10-11 months of continual operation. After that time, they must be changed out.

4) UV lamps must be matched to the proper transformer. If an incorrect transformer is controlling current to the lamp, the lamp cannot function at maximum performance.

5) When we changed lamps (every 10 months), we witnessed clearer water.

This aquarium was heavily stocked with marine fish.

Cheers.

[monkeyman164]

What does a UV Sterilizer do for a reef aquarium or in general what is it for if it doesn't apply to my tank?

[Gecko]

Using this method of treating water is quite controversial amongst aquarists. Some consider it to be a waste of money, not all that effective, or suitable for fish-only, but unnatural for reef tanks, while others feel it does have its benefits for either type of system.

The general consensus is that an aquarist that has a well maintained and uncrowded aquarium, as well as follows good quarantine procedures when introducing new specimens to their system, a UV light filter is not necessary. For those that may be deciding on whether a UV light filter should be added or not, here are some other points to consider.

Most effective when run 24/7.

Most effective if the water is clear.

Most effective if bulb is new, or replaced regularly (at least every 6-8 months).

Most effective if the UV light penetrates less than one inch of water.

Effectiveness can be hindered if the water passes to fast past the bulb. Most effective if the exposure time of the water to the UV light is longer than one second.

The effectiveness of UV light can be hindered if there is light blockage, i.e. a salt encrusted bulb.

It can help to prevent future water borne pathogen reoccurrences, once the initial problem as been completely eradicated from the aquarium.

UV light not only kills unwanted organisms, but beneficial ones as well.

Because it can destroy beneficial microscopic organisms that some reef tank inhabitants may depend on as a food source, UV light should not be run during feeding time.

It only destroys organisms that are free floating IN the water as it passed by the UV light, i.e. it will NOT get rid of an ich infestation that is already ON fish, or cure a bacterial disease fish may have.

Should never be run when treating with any drugs or medications.

UV can also alter the structure of some dissolved chemical compounds.

UV light can be damaging to the human eye, so DO NOT look into the bulb.

Always unplug the unit when working on it to prevent possible shock if it breaks or gets wet.