Is a uz sterilizer worth it?

[Coryloach]

Algae wise, any UV filter will have an effect. Pathogens wise you need a really slow flow rate going through it. The specifications of the filter should tell you exactly how much but my 9W UV filter needed something of the likes of 200-300l per hour(80G/H) and the only way I achieved that is via a tiny powerhead pulling through a fine sponge as a prefilter(they do need pre-filters). But I reckon that although its just empirical evidence, the UV does work at getting fish to good health....sick fish, quarantine, etc..You don't need one in a well kept tank with sufficient filtration and water changes...but good for quarantines...

I find UV filters high maintenance because of the specific flow rate which is hard to achieve and at the same time ensure it does the job of turning the water over,..extra electrical stuff, inlets/outlets inside a tank, changing not so cheap bulbs every 6 months, etc...Mine stopped working and I binned it happily..

 

[tgambo]

I recently installed one to help with persistent algae in a seriously overstocked 75g tank. It took a little adjusting but i'm very happy i took the plunge.

As far as adjusting I had to order a smaller pump than I originally thought. I started with a 400gph and it did next to nothing. Before calling the supplier and yelling that they robbed me i decided to try a 200ish GPH pump. It's in my sump after mech and bio filtration and the return into the chemical section. With the slower pump it works great.

From my reading (mainly at American aquarium products best article i've found and where i bought my "custom 15w sterilizer" ). It seems as thou a longer bulb is much better. Try not to focus on the wattage as much as how much time the water is in contact with the bulb. Longer bulbs are definitely better. I would put two lower wattage uvs inline before I bought one with a higher wattage.

They are not a cure all. There was a bloom while I was on vacation because someone decided the opening on the auto feeder wasn't open enough and the fish were starving. They will help if you water parameters are not perfect but they are not a cure all.

 

[duanes]

I agree they are not a cure all, they kill free floating algae, but not the algae on your glass.
They kill free floating bacteria and parasites, but not internal, or bacteria spread by contact.
If a fish is hovering near the filter intake bacteria may get sucked in. If the fish is on the opposite side from the intake, fish in between, can still be infected.
If your pump is too strong, bacteria passing thru the UV unit may get a little sunburned, but may not be killed.
Working in water treatment, I went to many UV seminars, and lectures, they are not a panacea.

 

[Karlotious]

Could you place a directional UV bulb over an entire low flow tub and sterilize the whole thing though? It seems much less efficient to only focus the water through a narrow tube when a powerful enough bulb could sterilize an entire container. (Like a light over the refugium but a UV bulb instead.)

 

[duanes]

I have been to water plants that use UV, and what they do is place grids of many UV bulbs over shallow channels. The bulbs are placed about 1 foot apart every foot the entire length of the channel, and the length of the bulb the @ 3 ft width of the channel, with mirrored covers over the bulbs reflecting into the water.
These were cleaned often, because any dust or detritus would lower the effectiveness of the bulb.
I have considered placing UV in an overhead fixture on a timer above the tank and lighting the entire area just a for short period of time around noon, to simulate the tropical sun at that part of the day, just to see if it would be too damaging for fish (or not).
With certain tropical and desert reptiles it is considered mandatory to provide UV B.

 

[kendragon]

UV dosage is highest close to the bulb. Hence, the narrow quartz sleeve. You want the water up close as possible to the bulb and that is way the chamber is a narrow tube.
Shining over a tank will not get the dosage needed. Not to mention the danger of UV exposure.

Open chamber UV setups used for waste water are in a grid pattern layout. Usually with several rows. Spacing between bulbs allows the water to flow freely but yet is close to the bulb on one side or the other. 12" spacing means the farest the pathogen can be is 6".
I've seen some designs where there is no quartz sleeve and the actual bulb is submerged in the water to maximize efficiency.

Several manufacturers do offer multi bulb UV sterilizers with big chambers for aquaria based on the same principal of open chamber flow.

 

[Karlotious]

All good thoughts. Yeah i just did some research into water treatment plants and that seems to be how they sterilize (channels of bulbs). What about placing a bulb above the tub of water while also placing a mirror below the tub? Concentrating the light through refractors (light box). Or covering the outside of an acrylic container in reflective sheeting (aluminum foil, etc) Sorry i just find the use of a tube and pump to be inefficient lol

 

[kendragon]

Sorry but analysis shows that the tube and pump is the most efficient. What you're proposing is not.
The tube controls the pathogen over the bulb and the pump control a constant direct flow. Controlling the water is more important than controlling the shine.
Direct UV ray is stronger than reflected. Any blocked light from the UV bulb is inefficient which could come in the form of detris, turbulent or mixed flow or baffles. You will spend a lot of time wiping the mirrors and container walls.
Polished stainless steel chambers and quartz sleeve wipers have already been incorporated in some UV brands. The wipers have some benefit but the polished chamber is a gimmick.