Internal Green Water Killer Aquarium Filter Tank U-V Pump

This is a miracle pump. I've had aquariums on and off for the last 30 years and never have I seen this kind of algae bloom. I couldn't get rid of it. It was actually much worse than the "day 1" photo depicts. At the time I took that photo I had removed almost all of the decor due to having to do 50% water changes every 2 days. It was ridiculous. I didn't want to add chemicals that may or may not have harmed the poor fish that were already surrounded by horrible green algae ridden water. I did a lot of research online and this is the pump that was most recommended. After seeing a lot of photo reviews that greatly resembled my very green aquarium, I took a chance on it. I was extremely skeptical that a pump would eliminate the constant green water, but to my surprise it actually worked! I really wanted to do this review because nobody has mentioned using this pump for smaller aquariums. The listing for this particular pump says "for aquariums up to 75 gallons", it doesn't give specifics for small tanks; but I took a chance and tried it anyway as a last resort. My aquarium is a 5 gallon aquarium. They're very common in size and even 5 gallon aquariums can be subjected to the green water conundrum. This pump, even though it doesn't fit in my aquarium upright, it still fits lying down and is fully submerged. On day 1, I couldn't even see my fish unless they were at the front of the aquarium directly under the light. Day 2 wasn't really much different. I didn't think this pump would actually work, but by day three I could not only see the fish but I could also make out the heater on the back wall. My aquarium was clear enough by day 4 that I started moving my other aquarium decor back in. And on day 5 my aquarium was crystal clear. No green water, no traces of green water, and I can see everything in the aquarium including the wallpaper on the back wall. There were no chemicals added. I used this pump in my 5 gallon aquarium for 5 days and my water is more clear than it has been since this aquarium was established and cycled for the very first time. It's like a brand new aquarium and my fish are super happy. I don't know how or why this pump works, but it's pure magic. Having said that, this pump comes fully assembled. It includes oxygen tubing for aeration if you choose to do so. I didn't need the extra aeration so I didn't install that piece. It can be used 4-8 hours a day as the instructions suggest. I personally used this pump for 4 hours during the morning and again for 3-4 hours in the evening to get the results that I did. The results may vary given the size of your aquarium. I plan to leave this pump where it is for now. The instructions say once the water is clear you can reduce the time, so I'll leave it in the aquarium and gradually reduce the amount of time I use it. I did a 30% water change on day 5, AFTER that photo was taken and it was just to clean the gravel and debris from the standard aquarium filter. This green water killer pump is amazing and the results really do speak for themselves. I would have gladly spent twice as much money for the results that I got! It's truly unbelievable!! My fish are happy and their environment is healthy. I'd consider that a win! Highly recommend!!

This thing is AMAZING. We had an algae bloom after a water change. Tried to manage it with more frequent water changes and leaving the light off becase the tank is in an area that gets some natural light but plants still suffered a bit. Got to a point that our fish couldn’t see their food flakes. The only plus is that our shrimp began to thrive since they weren’t being picked on by our betta. Put the device in and within 3 days the tank was pristine. Not sure if it’s also because we have two filters running in it right now, we’re trying to cycle one so that we can eventually remove the other. I am beyond happy with the result, saved us a lot of of extra water changes and less stress on our fish as a result. 100/100 recommend!

After the typical brown algae a new tank experiences the first few months went away, I had crystal clear water for 6 months straight. One day I get up in the morning and was completely surprised my water was completely green. This was the first algae bloom I had ever had in my tank. I was annoyed by this to say the least. I don't like using unessessary chemicals and didn't want to use any kind of algaecide and risk my fish and plants. So I did the usual thing and reduced light and how often they were on. I regularly do a weekly 20% water change but I upped it 50% twice a week. I still did my usual gravel siphoning once a week. I don't like to overdo cleaning my gravel because of my plants. Sometimes it looked like it was getting better but then a couple days later, it would look worse again. I battled for about a month and a half before I started looking into a UV sterilizer. I wanted a pump that completely housed the UV light to protect my fish and plants from exposure. After reading the reviews on this UV pump, I decided to give it a try. The price of $35 wasn't terrible and I just wanted my tank back to normal. When I recieved it, it was already put together. I read that the company tests their pumps before shipping them out to make sure they are fully functional. I appreciate that by the way. So I put it in my tank and plugged it in. It does have an optional bubbler if you want to use it. If you do want to use it, you will have to install it (parts are included). I already have a couple small bubblers in my tank so I opted not to use it. So I can't comment on how it functions. The pump has suction cups so it can easily be placed inside the tank. It should be completely submerged and can be placed vertically or horizontally. The instructions that came with it is pretty clear how to use it properly. There is also an indicator light so you can tell if the light is working or not. It pulls water into the pump and inside the pump, the UV light kills the algae that is in the water. Keep in mind, this pump only kills algae that is in your water column. Not algae that is on surfaces in your tank. On day 2, we didn't notice too much of a difference but it did look just slightly better. Day 3 there was definitely a difference. By day 6, my tank was clear. I decided to leave it in at least one more day because that would have been my weekly scheduled water change day anyway. Well, I'm glad I went ahead and left it in there one more day because on day 7, it wasn't just clear. It was crystal clear. I was so happy. My tank looked like it always had. You could even look in the tank from one of the side panels and see all the way at the end of my tank. By the way, my tank is a 55 gallon so you will have an idea of how much water you are looking through from the side. So on day 7 I unplugged it and removed it before I started doing my water change. I was finally able to fix all my hornwort that got blown around while the pump was running. I only have 2 cons when it comes to this pump. The water flow that returns back into the tank is pretty strong. It was a pretty strong stream of water that blew my hornwort all over my tank and my fish couldn't swim against it. They did quickly figure it out and stayed out of the stream. I did have to feed my fish at the opposite end of my tank so the water flow didn't reach them. Con number 2 will be the size of this thing. Even in my 55 gallon tank, it was big and chunky. It was kind of an eyesore. However, I didn't try to hide it or anything but I had no intention of leaving it in there. Overall, the cons that I have with it doesn't keep me from giving this pump a 5 star review. It was only temporary in my tank so the fact that it worked as well as it did outweighs the water flow and the size of this bad boy. You should run this pump 4 to 8 hours a day at least. However, it does say you can run it 24 hours. I ran mine 24 hours until my tank cleared. I have included photos of what my tank looked like each day. My camera couldn't pick up just how green my water actually was. We couldn't see our fish very well until day 3. I didn't even notice we had new molly fry until day 4 or 5. And to my surprise after my water cleared enough, I saw that my java fern and anubias plants had new leaves! Regardless, in my photos you can still see the day to day changes. Always remember, a UV sterilizer may remove the algae in your water column but it doesn't fix the reason for an algae bloom to happen in the first place. Algae usually happens because of lighting issues and too many nutrients such as phosphates. So make adjustments if you need to and don't rely on a UV sterilizer in place of regular tank maintenance. Bottom line, if you have green water and tried everything you can to fight your algae bloom and want to try the UV method, I highly recommend this one!

The COODIA Internal Green Water Killer Aquarium filter does a good job clearing up green water and improving overall water clarity in my tank. It’s easy to install, fits neatly inside, and runs quietly without bothering the fish. I’ve seen noticeable improvement in water quality within a 6 to 7 days, which is exactly what I wanted. It’s a useful tool for maintaining a healthier aquarium without too much fuss. The only downside is the bulbs only last about 4–5 months before needing replacement. That adds to the ongoing cost, but the unit itself performs well. Overall, this is a solid option for tackling green water, just be prepared to replace bulbs more often.

Worked great for me! I’ve had it for almost a year now. Initially, my tank was heavy with algae and I couldn’t get rid of it. It took a few weeks to clear it all out. But it worked great! Now I’m using it again and it worked, it took a couple days to clear out the little algae I had in the water. Great product!

Let me start by saying this is I believe my first review and I’m doing it because how amazing this product is and to also help people prepare themselves to use this product as I feel I may have made some mistakes but everything worked out great for me. If you have green or milky water and have the funds available do yourself a favor and get this. After tons of trial and error and research I believe this is the best and most natural beneficial way to clear an algae bloom or bacteria bloom all though i usually would just let a bacteria bloom play out. I wanted to say this to help some people with what i realized once i got to this point. I cleaned my filter took everything apart added a sponge filter would change ~30% water everyday adding polyfilter everything. Last day I took all ornaments out gave a deep gravel cleaning and still next day green cloudy water. I wanted to tell you guys this because in the process I was removing so much beneficial bacteria and changing my water chemistry so much that I could’ve caused an ammonia spike or crashed my cycle. You can always add beneficial bacteria but that’s the thing that will be free swimming live bacteria which will end up being killed through the sterilizer where as all the b.b you have in your tank on the glass ornaments gravel will not be harmed. What I ended up doing to play it safe is I would add some bacteria right on my filter and turn off the uv pump for the night just in case. Let me say within 3 days looking so much better 5 days really nice and now one week it looks like glass like absolutely beautiful water my parameters are all in great shape. This is your go to even though it may vary it will work be patient as you see my review and so many others saying it works it does. You can now see the blue light easily through both sides of device so those problems are gone only thing I’ll say it this thing is big it does take up quite a bit of room but I plan on taking out soon and seeing how the tank reacts and use again as need be but would keep in if needed regardless of size due to how great it works. Main point it’s just green water if your fish are alive and healthy that’s most important. Don’t go crazy tearing your tank apart. Give it a normal cleaning with gravel vac check filters change if need be as your usual routine and buy this thing plug it in and observe your tank it’s going to work and your fish will be happy and healthy. In this time research uv sterilizers and see if you want to have one 24/7 in your tank there seem to be many benefits but if you need your water cleared up looking beautiful this is the product and a great price.

I bought this item back in October of 2025. I don't usually do reviews but I had to come back to make one because this product is amazing! I was having horrible issues with algae bloom in my fish tank. It didn't matter what I did, it would not go away. My tank was solid green. After placing this uv filter in my 35 gallon tank, I have not had an issue with algae bloom since, until the uv light went out. It was so easy to replace the bulb and I am again back to a crystal clear tank. I highly recommend this for anyone having issues with algae bloom. Life saver, literally. I am attaching photos to show the progress of my tank after placing the uv filter in it. It took several days to clear but my tank was in a bad state. Seriously go buy it!

This aquarium filter is definitely effective when it comes to what it’s designed for. It clears up green, cloudy water surprisingly fast—usually within a few days to a week—and can make a dramatic difference in tank clarity. Once running properly, the improvement in water visibility is noticeable and almost immediate. However, the UV bulb lifespan is a major downside. It tends to burn out or lose effectiveness much sooner than expected, which means ongoing replacements are needed. That adds up over time and takes away from the convenience of the system. The unit itself is also a bit of a mixed bag in terms of value. It works, but considering the cost plus the relatively short bulb life, it feels overpriced for what you get. Maintenance and replacement parts become part of the long-term expense. Pros: -Very effective at clearing green water quickly -Noticeable improvement in water clarity within days -Simple concept and easy to run in tank Cons: -UV bulb life is poor / burns out relatively fast -Replacement costs add up over time -Overall expensive for long-term use Overall: A strong performer for clearing algae and green water quickly, but held back by short bulb life and high long-term cost, making it effective but not very economical.

Dont buy it !! Its not worth your money the material is not that great (feels cheap) plus its 120V with US plug the seller doesn’t say it so be careful.

Muy recomendable, cumple con la función

Product looks great but I wouldn't risk plugging it in as it does not appear to be dual voltage. Please include the voltage rating on the website and stop selling this in the UK before you cause an electrical fire. A stepdown converter will cost as much as this product and be noisy. The actual component looks good I just dont think Amazon should sell it in the UK.

The thing they don’t tell you is that it’s a 2 pin plug which I am struggling to get hold of and it’s not a two pin that they use in Spain it’s a US 2 pin