For years I got used to water change day being about getting the tank to look clear again, and of course nitrates , but I always knew I hadn’t done it soon enough as my tank water would start to turn color …Installed this, I still of course do my water changes , but you wouldn’t know if it was a day or two weeks since I did it because the water is clear all the time.Now my plants love it and stay green , they don’t fight algae for light anymoremade my water crystallll clear in 2 daysMy aquarium was greenish and cloudy! Could not get rid of it! Until I hooked this up and wow! After 3 days crystal clear!! Works unbelievably well!!This product does not come with a pump or with any hose.Have this hooked inline with canister filter, and the tank has stayed sparking clean. No algea or related growth ever.The unit is a little small for a 75gal tank it took about a week but doing the job nowWhat you expect when you buy it, a great inline sterilizer that is a little difficult to set up initially, but seems to work great.I fought for months with algae overgrowth in my aquarium, trying everything. Read the reviews on this product and was impressed with some of the comments concerning its efficiency. So I purchased it. It took a little longer to completely clear my tank than reported but, as the algae was so dense I couldn't see my fish, I feel it truly lived up to the reviews. I would recommend this product in a heart beatI think its gallon rating is exaggerated. I have a 75 gallon that was blooming (biological) bit did improve but took over a week and never really got perfect. I watched these in action on YouTube and they were testing with the next size too big with fast results. I think I would recommend by the next size bigger than you think you need if you are approaching the limit.Aquarium water is much clearer now after installation. The only complaint I have is that the mounting clips are very flimsy if mounting the unit in a vertical orientation. This is how I mounted it and both clips broke within a couple of days. Other than that issue it works great. I wished now that I would have bought one years ago.Really excellent tool if you have an existing canister filter and suffer from algae blooms. This sterilizer clearer up my tank in about two days after installation, which was straightforward with the included mounts and adapters.after about 3 months of use, i opened the incide for a cleanup, and the glass seems all burned and yellow, i am sure this will hinder the quality of UV sterilization. would like to return it but i am sure it will be refuced now.