JAHEA Aquarium Clean Light，13 W Submersible Light with Timer,Double Tube Aquarium Water Clean Green Clear Waterproof Clean Lamp for Pond,Swimming Pool,Indoor

I have a tank with an internal filter. There's plenty of space to drop this in there. It's behind the tank so the fish and myself are protected by the light. Nothing about this can possibly kill your fish unless you put it in the tank where the fish are exposed to it or possibly have used certain additives in your tank that warn against using with a UV so be sure to check the instructions on anything you place in your tank. This will help your tank stay cleaner by killing free-floating algae which high wattage UVCs are not needed. The timer is nice, but it's best just to keep these running 24/7. Price of these is generally cheaper than a replacement bulb for a regular UVC so this is cheap enough to toss every 6 months or yearly.

If you put it in the tank and can’t keep the fish from being exposed to the lake, then all your fish are gonna die

Cleaned my fish tank

I have always used traditional uv clarifier in tank setups. I was reluctant to try this. However, my canister return is an hob, so I dropped this in for the night. Came back next day and tank was already 50% clearer. Turned this on to run for 24 hours straight and the tank was completely clear within that 24 hours. Now I have the timer set to run for 6 hours at night. Keeps water crystal clear. I bought another one.

Though it does clear the water it also killed all of my fish. I didn’t know that was the cause of my fish dying after multiple attempts of getting new fish it’s been linked to the uv light. I recommend if you want to get this remove the fish from the tank while you use it in the tank.

Installed in the tank and the next day my fish were dead. Not happy about this at all.

After using, frequency between cleanings seemed 1-2 weeks longer.

Installed the light the morning after receiving the item.The next morning, the water was a bit more clear. But 2 fish were dead.Do not recommend.