Review on 🐠 4L Aquarium Auto Water Level Filler Controller and Coral Marine Tank Top Off System - Optimized with Siphon Principle for Automatic Water Addition in Aquariums by Dana Lynn

I have a 40 gallon reef aquarium and am tired of manually adding water every day. The container works perfectly and serves its purpose. Based on evaporation from my tank, I think a keg of water should last about a week. Once it's empty, you'll have to remove the container to refill it. I wish they had a funnel with them as the hole is about the size of a water bottle cap. Generally a working device.