I wiped off the oil with paper towels, put it in the sink, ran a little water through it, and it worked fine, without leaving any oily residue on the water. I put it in the aquarium, and took the first pic five minutes later. *NOTE: I learned that the 5 watt U.V. lamp is impossible to see during the day. One the first few days the water was so …

https://www.amazon.com/COODIA-Internal-Aquarium-Submersible-Disinfection/dp/B07V26V5MS