UV sterilization thread

[StirCrazy]

UV seams to be a hot spot where you either love it or hate it.. so lets see why people like it or not and why. there are a lot of "OLD" thinking and such when it comes to UV some right some wrong but all of it needs to be weeded out so it becomes clear.

I'll start out. I for one am for UV as i believe it is more beneficial than harmfull.

it destroys free floating pathogens, protozoans and algae. all good in my books.

what about the pods swimming around you ask... sure it may zap a leg off one but due to there multi cellular make up and size in most cases they will be just injured.. guess what, fish will still eat them even if they were killed

some people say you need to get a huge sterilizer for a home aquarium.. i don't think that is necessarily true but you do need to match the pump up to the unit to give the proper velocity of flow through it.. if your flow is to fast it will not be as effective as the dwell time is reduced and if it is to slow of a flow you might be zapping more pods than you would normally.

now having said that I think they are just 1 more tool we can use to maintain good water quality if used correctly.

Steve

[sleeman]

I said undecided, and here is why.
I am by no strech an expert when it come to SW. SO please don't blast me for this post.
I had a 100 gal FOWLR in 92-96. I used crushed coral, live rock and 2 HOB filters. I also had a cheap 50 dollar skimmer. I was having several problems with the water quality, and ended up with a 36" UV. It cleared up all the problems, and I did not see any problems start because of it. It did not however stop any fish related illness. And I had a few of them.
I am now running a 75gal reef (reef used loosely) tank with only LS, LR, and a high quality skimmer. I have had no issues with water quality ....Yet. Nor have I had any fish illness. Just jumpers
I am sure my time will come. But the main difference I have found this time around, is the ability to get on the net and ask questions. Before I just went to Gunther the fish guy and bought whatever he told me to buy.

So, I think that UV sterilizers have their place, but it will be one of the last things I put on my tank. I will try to let one of you guys/gals solve my problem. I would rather put in some work into solving the problem than throw another product and a bunch of money at it.


Cheers,

Al

[StirCrazy]

Originally Posted by sleeman

SO please don't blast me for this post.

Cheers,

Al

I hope none of that goes on at all, I personaly want to hear the opinions weather they be good or bad. the more input the better it is to put things togeather.

Steve

Ill have to vote a big yes for UV. Almost every fish and invert farm in the world rellies heavily on UV filtration and they dont like to throw money around, they use it because it works...

[Aquattro]

Originally Posted by UnderWorldAquatics

Almost every fish and invert farm in the world rellies heavily on UV filtration and ..

Kyle, the point is what type. I know the treatment plant in Kelowna also uses UV, but nothing a guy could hook to his tank!!
I think the question arose from the assumption that hobbyist units don't work as well as their larger commercial counter parts.

[Quinn]

Do coral farms use them?

[saltcreep]

They great if they are cared for. Never buy a unit w/out an internal wiper so you can clean the sleeve. If they aren't cleaned at least once a week, don't bother spending the money on the unit or the energy to run it.

like SaltCreep said, the UV units with an internal wiper are great, and sorry for the short reply, I had no time to type anything out....
yes UV is used in coral farming, crustucean farming, fish farming and water treatment. Small UV units are great for use as clarifiers, if you want to use UV for sterilization, then you need to bump it up a notch.

In order to protect aquatic livestock held in aquariums or holding tanks, biologically treated water should be adequately disinfected before returning it from the filter system. Mechanical and biological filtration does not provide inactivation of pathogenic bacteria, protozoa and virus.
Ultraviolet radiation (germicidal) energy is unmatched in its efficiency, simplicity and dependability when applied as a microorganism disinfect! It is most effective for its germicidal value in a clear water application at a wavelength of 265 nanometers. With proper exposure, ultraviolet radiation energy (ultraviolet light) penetrates a microorganism’s cell wall. It then destroys the nuclear material, causing abrupt modification and quickly bringing about its destruction.

a lot of people have ultraviolet (UV) sterilizers and are still experiencing disease problems. This can almost always be traced back to inadequate UV irradiation. Because it is so difficult to measure the intensity of UV energy hitting the water, many buyers have improperly sized their UV sterilizers by simply following the maximum gpm flow rate published for 15,000 µW sec/cm2. (Who said aquaculture was easy?)

Be careful! You cannot compare UV Sterilizers by the watt ratings alone. That would be like comparing cars by their engine size alone. The watt rating is just the starting point for comparisons.

The full amount of UV energy required to kill a microorganism must hit the organism after it leaves the lamp, after it leaves the quartz sleeve, after the lamp has aged, and after it has passed by any turbidity and color that is blocking the light.

Low-pressure mercury type UV lamps are best suited to germicidal action because the primary radiation generated by these lamps consists almost exclusively of a spectral wavelength of 254 nanometers, which is close to the maximum peak germicidal effectiveness wave length of 265 nanometers. This gives the low-pressure mercury type lamps an exceptional 40 percent UV energy efficiency rate between input watts and UV output watts.

Medium and high pressure mercury type lamps are best suited for treatments involving chemical by-products associated with industrial waste water or for the drying of printing inks, paints and adhesives, not germicidal action.

The bulk of their power is in the 320 to 440 nanometer range, well outside the germicidal range.

Ultraviolet light can be very effective at eliminating viruses, bacteria, algae and fungi. The required UV exposure rate to irradiate common bacteria is 15,000 µW-sec/cm2, while the required UV exposure for waterborne algae is 22,000 µW-sec/cm2. Since it is the intensity of light that is doing the killing, we must know how much light energy to use and how much is reaching the target. Just as some sunglasses and sunscreens reduce UV intensity, so does discolored water, turbidity, dirty quartz sleeves, and even some dissolved salts, such as sodium thiosulfate. Even lamp temperatures can reduce output when operated in cold water (110°F gives maximum UV output).

To insure sterile water using UV light, first start with clear water, and have a lamp and flow rate that are sized to deliver the correct amount of irradiation for the target organism (see exposures list). If a UV light is flow rated for 15,000 mws and you want 30,000, either double the amount of lamps or reduce the flow by half, and so on for higher dosages.

Be aware that some lamps age rapidly and the manufacturer probably states the watts produced when the lamp is new. This wattage can be reduced by as much as 40 percent in as little as six months! oversize the UV sterilizer by at least 40 percent to be sure of getting the killing power required when the lamp has aged. changing lamps at six month intervals. µW-sec/cm2 = Exposure to ultraviolet light of 253.7 wavelength in microwatt seconds per square centimeter.


thats some excerpts from some of my aquaculture books, you can look up UV sizing on many websites.

[Samw]

I ran a small Lifegard UV sterilizer back when I first started reefing and my fish had ick. It actually didn't help and the fishes still had ick. I guess the wattage was too low for the 38G tank. But the other thing about it is that it kills phytoplankton and I'm not sure why I would want to kill the things that I actually purposefully buy and feed my tank (DT's).

Maybe a larger UV sterilizer might have saved my fish from Ick and Clownfish disease (not sure). I suppose it might be useful for fish only tanks and maybe not useful for coral only tanks?

[TANGOMAN]

I'm of the belief they are of minimal value in a single system. Given the high cost of the unit and the ongoing cost of crucial bulb replacement. I think the money would be better spent on efficient skimmers etc. Though this does not erradicate pathogens, it will greatly improve water quality thus reducing one of many possible stress factors.
I had used one for many years on a single system and suffered losses far greater than I do at this time. Those losses were certainly not as a result of U.V. sterilization.
They were, I believe, as a result of limited experience, knowledge and guidance. These were times before boards like this existed and guidance was obtained primarily from sales staff at local retail outlets. This can be very dangerous guidance, especially for the anxious rookie with a tank full of dying fish at home. Guidance on these boards can be equally dangerous if not used properly but we are least given the opportunity to gather as many opinions as possible in a short period of time. Sure, there are alway different opions and the occasional "clash of the Titans"...
I guess what I'm tryin' to say is that a U.V. sterilizer would not be placed high on my list of priorities for required equipment to successfully maintain an aquarium.
Multiple unit systems are another story, where new arrivals are "ticking time-bombs" and given the space limitations to accomadate new arrivals, quarantine practices are not always an option. Not to mention the common desire to turn the inventory over as soon as possible to reduce losses. I'm not saying thats right but it's reality. U.V. in these situations is certainly a logical "preventative measure".
U.V, like many other products/practices in this hobby, has it's place.
Where do I vote for yes and no...