AA Aquarium Clip-on UV 3W GKM

So I have owned this product for about a year now and I feel I have earned the right to comment on whether this light really does the job... bottom line... yes it does.How do you know for sure?Well basically just above the light (in the filter) I see a huge amount of green algae and bb algae, but underneath the light and in the tank, I rarely ever see a problem.Is that all you do to control your algae?NO, I also use PhosGuard, and together with keeping a tight reign on my lights (~6-8hrs) and the amount of food for my feedings... I was able to almost eliminate my algae issues.Will it fit on my hobfilter?Most likely YES. Note that it errs on the small size, so while not all the water leaving your filter will make it through to the light, it will be able to be used with almost any nano sized hobfilter you might have. Also know that since this light works 24-7 chances that all the water from your tank will make it through the light eventually is extremely high.Will it kill my beneficial bacteria?Doing a basic google search on this question for UV lights I came up with the answer... no (but I recommend that you check for yourself). I am very serious in cycling my planted tank since I kind of push my bio-load to its limits so making sure my nitrites and ammonia stays at zero was always a huge deal for me. So far after a year, I have never had a problem.Why this light, and not another UVlight with its own motor/pump?This was a big question for me. About a month before I first purchased this light, I bought another AA UVlight with its own motor. In about a month the pump died and the UVlight (which still worked) was rendered useless. There were a couple of other problems, the unit was rather expensive (~$60) to begin with and the current it created was only acceptable for some of the fish in my community tank. But the worst part of this UVlight was with the noise from the pump. I have my tank in my office, so not hearing any sound from the motor is a HUGE issue. I could have risked getting another UVlight w/ a pump from another company (and drop another $60 somewhere else praying that the new motor would not make an annoying sound) OR I could spend ~$25 on this light and use the motor that I already have with my hobfilter. I am super glad that I decided not to go with another UV system. Not only does it save money w/o the extra electricity, but it keeps the back of my tank from looking so cluttered.What are the downsides of this product?There are a few.1) It rides low on the filter. So if you like to 'top off' the water in your tank like I do, chances are, your light will be submersed in water most of the time which I bet lowers it's efficiency (but keeps the unit form over-heating).2) If you have tiny floating plants, there is a chance for them to wander into this light from time to time (but honestly this is not a huge issue)3) The chord that extends upward from the light kind of looks weird to be honest (but is not that big of a deal to me)4) It is hard to tell if your light has burned out or not (there is a little green indicator light along the chord that you need to check, but you have to remember to do so)5) It may not be enough for a real large 100+Gal system (but if you hang out in the slow and steady wins the race camp, I am sure if would work out in the long run)Other than that, there is not much to say. I have already re-ordered this light for another 10gal tank, and I am super glad the way that it is working for my 20gal. Hope this review helps

This is really small sterilizer with tiny 3W lamp. The width of the "mouth" is only 2 inches - see my pictures, so unless you have small filter for entry level tank, this sterilizer will sit on a side just like mine. The instruction manual is poor, it does not even says how to install clip as it comes as separate piece. After a minute of figuring it out by looking at photo on the box you should be able to attach it properly. On the other hand the instruction warns against using undersized extension cord with this sterilizer which could cause an overheat and fire. How ridiculous this sounds with 3W device, where the smallest 120VAC cord in US is rated for about 700W (6Amperes), duh.The instruction also shows the sterilizer to be installed above the water surface so if your filter discharge is low then you may need to drain some water from your tank, just like I had to. It was not a big deal but for some setups it may be cumbersome. Also, be careful of you have tank cover, the sterilizer may collide with the cover, depending how far above the filter discharge the cover is installed.The green LED is located in separate piece (power reducer from 120VAC to 12) installed directly on the AC cord. Because safety of the product is critical when used in proximity with body of water (fish tank) I checked if this power reducer is UL listed and it is under E335411 E-file which guarantee design and build meets United States Under-witting Laboratory safety standard for use of mains powered appliances.The idea of using filter flow is smart but execution is somehow weird, I wish they made larger version with larger lamp inside. The pictures in the amazon listing are misleading cause they make device look at least 2 times larger. I think I will shop for regular submerge filter going forward.

This is the second of these UV sterilizers that I have purchased for my 10 gallon tank. The first was almost exactly a year to the date I purchase the second. I had been fighting with an algae bloom, did a 100% water change and cleaned the gravel and then a couple 50% water changes and nothing made the water as clear as I wanted and had had in the past. When I opened the second sterilizer I read that they actually last about a year, maybe more, depending on number of fish, how good you are about cleaning the tank and doing water changes, etc. Three days before I left for vacation I placed this new sterilezer in the tank. Someone was staying at our house feeding our cats and my fish but was not cleaning the tank. I didn't see a noticeable difference over the three before I left but when I came home 10 days later I COULD NOT BELIEVE HOW THE CLEAR THE WATER WAS! I mean, really...look at these two pictures! It looks like air! I mean, the tank is so clear it's almost creepy! I did nothing besides replace the UV sterilizer and this was the result. I don't when when over the ten days I was gone that the magic happened but it clearly did...no pun intended! Ok, pun intended! Bottom line, for the money and the result, I will purchase one of these per year if that's what it takes to have this result! You should too!

I bought mine used, hesitatingly because of the negative reviews. (Also, I have a 55 gal. tank so this was going to be a tester to see if they helped at all before spending more we really can't afford.) It worked amazingly! The cloudy water is clear in only a few hours' use and my fish can see what's food again! I did do a gravel vacuum and replaced 1/4 of the water but it was still a puke colored dense fog mess until I plugged this in. This little miracle worker made all of us happy again and I'm very appreciative. The others' pics are not an exaggeration in any way. Highly recommend + would buy again!

Update*I was looking at buying more of these, as I'm probably coming up on the end of life of the two I have. But they have more than doubled in price... That's just ridiculous... I could understand 10 or 15, but come on. I'm looking elsewhere now.I was skeptical... A few of the negative reviews had me doubting this UV Sterilizer. However, it cleared up my sons 20g tank in almost a week. I felt like it wasn't doing anything at first... But it proved me wrong in the end. I love that it clips on to the waterfall filter already in your tank. Mine has a really small lip, but it was enough.I also didn't have to take out much water. One revieade me think I would need to remove quite a bit.Oh, and I bought a second one for myself... Lol.

Took just a bit over a week but the 10gal tank had been cleared of algae completely and I believe it also destroyed some other bacteria in our tank that was causing problems because the fish are doing much better and behave much more lively. Excellent product at a fair price. Really works.Update: After 2 weeks water is crystal clear. Could not be happier.

This product really works. My 5 gallon planted tank has very stubborn green water problems all the time. Frequent water changes, less plant fertilizers and less hours of lighting did not help. I used this UV Sterilizer continuously and water started to clear up in about 5 days. My tank is getting direct sunlight for about 2 - 3 hours every morning and this UV sterilizer keeps the water clear. I have a AquaClear hang outside tank filter and this UV sterilizer is the only product out there which is compact enough and clips onto my filter outlet nicely. Thank you.

Awesome little UV sterilizer. Because it’s a little smaller, it took a week to clear the algae from a fluval 45 gallon tank, but it did eventually clear everything up. Clearest the tank has been since we bought it.

we have a pretty bad algae bloom in our tank. It was so bad you couldn't see through the tank. We tried multiple small water changes, reduced feedings and reduced LED lighting and none of that worked. We bought this UV light on the advice from our pet store and after a week the water is almost back to being 100% clear.