Worked like a charm! I had a persistent bacterial bloom in a 65 gallon freshwater cichlids tank that no amount of cleaning or frequent 15-30% water changing could remedy. My Fluval 405 filter wasn’t making a difference whether I cleaned it monthly or every 90 days. I asked my LFS their opinion on UV sterilizes and was given a “won’t hurt if you try” response. After a lot of research online I paired the 394 GPH flow from my fluval with what I could ascertain was the right wattage and volume UV sterilizer size and read all the reviews I could find on all brands. Decided on the TT 6X and was very pleased with the unit. Sturdy and easy to set up (although I was dealing with splicing it into the flex hose that Fluval seems to love - nothing a little marine epoxy and spare adapter end couldn’t handle) I had it installed and functioning in about an hour. Ran it for 4 days and VOILA crystal clear water!I did lose one fish a few days later. Although the water was clear I didn’t monitor the water quality as closely as I should have. I tested the water when I found a large green terror belly up and as it tuned out, the nitrite level in my tank had spiked dramatically. Every parameter but that was perfect, but one fish RIP and two others clamped tight told me there was a problem that needed immediate attention. Small water changes for 3 days and a dose of live beneficial bacteria to boost my tank had the nitrite back in check in short order. I also backed down the run time of the filter to 4 hours every night. Water quality still pristine after 2 more weeks.The coralife did exactly what I wanted. Had I been coached to check water quality daily after installation the experience would have been flawless.I highly recommend the Coralife UV sterilizers and will buy it again for other tanks.