First of all, yes, this tank is very green, I got sick of taking everything out and scrubbing it and refilling it weekly. I normally clean it before it gets this bad, but I somewhat gave up while waiting for this BEAST of a filter to arrive. I have tried all sorts of water treatments, I've tried putting the fish on a diet, I've tried less light (and leaving the light off for a week), ive tried letting the tank run it's course as reddit suggested. And then I came across the UV light filter thread, and thus came to the conclusion, that if this filter didnt work, im selling the tank (no not actually, but MAN was I FED UP!!!) This filter works AWESOME. I took a picture of the water progress every day and numbered them. There are no water changes, no changes in feeding amount or schedule, and no water treatments (until day 11, and 12 where I put a half dose of water clarity solution and algae fix for a total of two days). The end result is perfectly clear!!! I'm blown away at the power this thing is capable of. I was sceptical for the price, and when I plugged it in, the light didnt seem very bright (it's ultraviolet... duh) but the pictures speak for themselves. It takes a bit of time, and there are days where it seems like not much progress was made, but it does work! If you have smaller fish, I recommend the rainfall attachment, it'll airate the tank still if set up properly, and not push them around too much. Also, when using this filter, I recommend using this filter AND your old one in unison. This filter will kill off the algae, and the normal filter will pick it up. On day 11, I noticed the water was hazy, but not green, and that is the day did one cartridge swap on the old filter, and start treating the water. I used API Accu-clear, and API Algae Fix. Half doses every day for two days and it was able to clear out the remaining fog. The Algae fix was not normally successful in clearing out the algae and would come right back before I bought this filter. I EMPLORE you to buy this filter. GAME CHANGER!!! Also please note this filter does an admittedly poor job at filtering waste of any sort, it has a loose mesh around it and that's about it. I can't forsee fish getting sucked into it, BUT it's not very good at filtering anything but algae, but that's what I bought it for so that's totally fine. Id give this filter 10 stars if I could. Read more
AMAZING. If you’re dealing with an algae bloom in your fish tank, skip the chemicals and BUY THIS FILTER! I thought the reviews might be too good to be true, but all of the before and after photos had me convinced to give it a try. The ecosystem of our 20-gallon tank was all out of whack, resulting in a bacterial bloom, and then an algae bloom. Because the chemical balance was already so messed up (which caused our multitude of blooms in the first place), I didn’t want to dump a bunch of chemicals in the tank and make it worse. Some time on Google pointed me in the direction of a UV light to deal with the algae bloom. I bought the model designed for 10-30 gallon tanks, and it seems to be plenty big for my 20 gallon tanks. I ran the UV light for 24 hours a day. (I’m currently on Day 13 of use and still running 24 hours a day.) I took other reviewers suggestion and used the rainfall attachment for the filter. At the same time this UV light filter is running, I also kept my other filter (Marinelane Penguin PRO 175) going as well. This seemed to help filter out the dying algae, and I rinse the cartridges weekly. Be patient, this UV light should help if you’ve got an algae bloom. (Heck, I think it’s helping with my bacterial bloom as well!) I didn’t see much of a chance for the first few days, but starting around Day 5, and there was a real improvement in visibility into the tank. I’m currently on Day 13 and the tank isn’t entirely clear yet, but that is due to the bacterial bloom (that most likely caused the algae bloom in the first place), and I’m not expecting this UV light to clear that up. Read more
Well, it works as intended. The water is crystal clear after about 48 hours of constant use. Only one definitive negative; The flow is HIGH and You can't adjust it at all, so I had to rely on using the rainfall attachment, in the water, directed at the side wall to create a whirlpool effect rather than just blowing water from end to end. I have a heavily planted tank with small fish I didn't want stressed out by excessive water flow. I probably could have gone with the smallest size for my 40 gallon tank. Outside of that, it worked! I tried everything to get my white cloudy water, that's been visible for weeks, to clear and it barely took 2 days. I did take it apart out of curiosity so see how the flow works. Water passes through the filter on the back and is forced through a grill on the lower end into the light compartment before it's blown out. So nothing is obstructing the water from being exposed to UV light at all. (Some others I noticed have filter pads encasing the light, which seems very counterintuitive) Anyway, highly recommended. Read more

