GKM9W

I am a cheerleader for the Green Machine ultra violet light filter. I have used this product for many years with all types of fish, exotics, and turtles. Depending on the size of your tank, have reasonable expectations if you buy the 9W and not the next size up depending on the size of your tank. The smaller unit clears the water up to 50 gallons to crystal clear visibility and also protects against algae and other listed contaminants. There is absolutely no noise to this unit operating as a submerged unit. I sometimes let the output tube sit above water level for some aeration, but even then it is a small trickle. The unit is made of high quality durable plastic, and I've never had damage to any unit with ordinary use. A replacement bulb may be purchased after the usable lifespan of the UV light has passed. This is hard to gauge in terms of duration, but I have waited to replace the UV lamp between 6 months to a year. If you use it constantly the lamp may lose its utility sooner, but it responds well when using a timer to extend its lifespan. I have had canister filters with internal UV lamps, but the GKM is great for smaller tanks that don't rely on heavy filtration. It comes with a grooved plate that attaches to the interior tank wall with suction cups and the unit itself can be inserted and removed easily without detaching the plate attached to the tank. Another feature worth noting is the unit's power box to be placed on the outside of the tank which has an indicator light to let you know that the unit is working. There is a small filter included to cover the intake to the lamp. I've never had a problem with fish, but turtles like to dislodge the small filter and 3 or 4 replacements come with the purchase. Although it's stated purpose is to kill algae, knowing the UV lamp is there puts me at ease knowing that I am doing everything possible to maintain water quality for my critters. I highly recommend the GKM.

​If you are struggling with murky, cloudy, or green water, stop scrolling and just buy this. I was dealing with a serious clarity issue in my planted aquarium (as you can see in my "before" photo), and nothing seemed to help. I decided to give the AA Green Killing Machine (9W) a shot, and it absolutely exceeded my expectations. ​The Results: ​Day 1: I noticed the "fog" starting to lift slightly. ​Day 2: Massive improvement. I could actually see the plants in the back of the tank again. ​Day 3: Total transformation. The water is now crystal clear—it looks like the fish are floating in mid-air (check out the "after" photo!). ​Why I love it: ​Insanely Effective: It did exactly what it promised and did it fast. ​Easy Setup: It took me less than 5 minutes to get it installed and running. No complicated plumbing or tools required. ​Quiet: I barely even notice it's running. ​Safe: My fish, snails, and live plants (Pothos, Amazon Swords, etc.) are all doing great and look healthier than ever now that the light can actually reach them! ​I am beyond impressed with how well this worked. It performed way above expectations and saved me from a massive headache. I would 100% buy this again and highly recommend it to any hobbyist dealing with water clarity issues. Best investment I’ve made for my tank this year!

I bought the 9W Green Killing Machine to deal with a sudden algae bloom problem in my established 20-gallon tank. It didn’t work quite as fast for me as some of the dramatic “24 to 48 hour transformations” you see online, but it definitely worked. I took pictures every 24 hours, and by day four the water was noticeably clearer and still improving. So if your results aren’t instant, don’t panic it just needs a little time. Before buying it, I had a few concerns that I know other people wonder about too. First, I worried about noise. Thankfully, the unit is virtually silent during normal operation. Installation was also extremely simple; it took only a couple of minutes from box to running. The water flow feels a bit weak at first, but that’s actually by design, the restricted flow increases UV contact time for better performance. I was also concerned about livestock safety, but it hasn’t bothered my shrimp, snails, or fish at all. Everyone stayed active and behaved normally the entire time. As for maintenance, I ended up taking it apart once because a small piece of grass slipped past the sponge and caused a brief noise. The good news is that it was very easy to disassemble, clean, and put back together. Another nice surprise: there’s no visible UV light while it runs. Even with every light off in the house, you can’t see anything glowing from the unit. The power cord is also plenty long, which makes tank placement flexible. Build quality is solid, and the unit is smaller than I expected. My tank is pretty packed with plants and decor, but it still fit easily the only drawback is that it sits toward the front and can’t really be hidden. Because of that, I won’t keep it in permanently, but it’s perfect to use whenever the water starts acting up. Overall, it’s a quiet, easy-to-use UV sterilizer that safely cleared my tank over a few days. It’s well built, livestock-safe, and simple to maintain. If you’re dealing with cloudy water and want a plug and play solution, this is a great option that genuinely works just give it the time it needs to do its job

Bought this in April and it started making popping sounds and got very hot by end of July. This used to be a good product but lately the quality has been poor.

I have a 3.5 month old 20g tank for my Betta, Otos, Hillstream Loaches, and various snails. I've been experiencing a "bacterial bloom" for about 5 weeks, even though my parameters have been perfect for months and my fish have been happy and healthy. I could tell my algae eaters were struggling a bit with the reduced oxygen, so I literally tried everything to get through the milky water phase. I finally broke down and made a post on a forum that I'm part of. Someone suggested more filtration, which I had tried, but the link they provided also suggested investing in a UV bulb as well. I wasn't feeling extremely confident, but the comments on this product had me feeling better. Many of the folks who bought this product got it to take care of an algae bloom, so I was a bit more concerned that it wouldn't help with my particular issue. I found a few great comments saying that it worked for their bacterial bloom and the price was great, so I figured, "What the heck?" It is similarly priced or even less than the cost of a second filter. This is an excellent product and it does exactly what it claims to do. I have had it in the tank for just about 3 days, but I already noticed a huge change in only 12 hours. The final photo is today (as of posting) and the tank is 100% clear from all angles. I'm sure that part of my issue was feeding my various algae eaters fresh veggies and yeah, I probably am leaving it in the tank too long. However, as many of you who have Otos, HSLs, or any other algae eaters likely know, mine don't gobble up food within 2 minutes like many other fish do. Now I don't have to compromise on what I feed them. They're happy, healthy, fed a diverse diet, and I don't have to compromise on visibility/oxygenation. I love this product and I would gladly recommend it to anyone facing any type of bloom in their tank that they've tried everything to combat. One word of advice, though: if your fish are sick, take care of them first. Put them into a hospital tank and care for them. Having visibility in your water will not heal your fish. Nor will most medications work if you put them in the tank with your UV light running. Happy fish keeping. ❤️

Great product! Had an algae bloom in the tank and water was lime green and cloudy. Installed this unit and within 3 days water looks amazing. Highly recommended.

I had tried name-brand algae killers, and they didn't seem to do much of anything for green water. Acurel-F would keep it nice for a couple of days, but then it would choke the filter. And continual water changes didn't help much, either. I had also tried other tower-style all-in-one UV lights in the past, but all they seemed to do was blast my poor fish across the tank. So, I came across the Green Killing Machine series, but was skeptical. I thought it was just a more expensive name-brand AIO UV light that I'd probably be sending back. But to my delight, it cleared up the green water slowly but surely. While this is rated for a 50 gallon tank, it isn't overpowered for a 10-gallon, which I was also very happy to see. The water flow is gentle, so it isn't launching fish, or sucking in all of their food. Once I had it cleared up, I ended up adding an interval timer, but that's where I docked a star. This uses an external control box (I call it a "control box" but there's nothing to actually adjust on it) and it seems to me that for what this costs, that would be a logical place to put a timer. And keep in mind -- the company recommends a timer to improve the lifespan of the bulb -- so not building one in seems questionable at this price point. That said, the amount of time it's already saved me in backing off on water changes has already more than covered the cost of an interval timer.

I had an algae bloom so thick I could only see about 2 inches into the aquarium. The bloom happened gradually, and at first it seemed white, like a bacterial bloom. All my research said leave it be, it will sort itself out. It finally got so thick I recognized the color as green, (some suggested dipping some of the tank water into in a white bowl to determine if it is an algae bloom-green or a bacterial bloom-white). Once I knew the culprit, I came across the solution for me, this UV light. It was easy to set-up, and it gradually cleared-up the problem. My tank is crystal clear now. It took about 10 days to clear-up my 40 gal breeder. I have taken it out, and made adjustments to my lighting schedule and intensity to try to address the original problem. Fingers are crossed I won't need it again, but it is an easy fix if I do.

Amazing product, water went from a cloudy green to pristine, within 3 days. Recommend for any aquarium owner. Save yourself the hassle and time of dealing with algae. Takes fine algae off glass and sand.

I was battling with an uncycled tank for ages. My beta got very sick and thought he wasn’t going to make it. Now… while it was the course of meds that saved him, this UV filter is what greatly improved his environment! Was plagued with bacterial blooms for the longest time which caused foggy water. 72 hours running this UV filter and the water turned crystal clear!!! I haven’t even had to use it since, but it’s great to have on hand!

Took about 7 days with filter cleanings as i had terrible algae bloom but i must say it gets the job done

Works excellent, water which was previously Cloudy was crystal clear in less than 24 hours in a 29 gallon tank ,I had originally given this product 5 stars however the bulb lasted less than a month of only intermittent use. For the price of the replacement bulbs this is very unsatisfactory. It was eligible for return. I did contact the seller and ask if they would be willing to replace the bulb instead of returning the whole unit but I didn't get a reply. For the price of the unit and replacement bulbs I am not willing to take a chance on another one . Will be returning and not repurchasing

I tried many solutions to clear up my green water break out. This was the only thing that was effective! Note: I did a major water change before installing the UV sterilizer, the cloudiness was still apparent at that point and would have bloomed again very quickly. However once the UV sterilizer was installed it cleared up in 3 days. My tank looks amazing again! Would only recommend using the pump when needed to preserve it’s life span as mentioned by the manufacturer.