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 Heather Coleman

Works as advertised but is huge. Not suitable for 5 liter tank. Bad design. For some reason they thought it would be a good idea to seal the top cap. To pour water, you need to remove the plumbing and unscrew the pipes at the bottom, and then pour water through a small hole. The black cover also sticks out a few inches, so if you attach it to the rim of the tank you'll need about 5 inches of space between it and the water level for it to work. If you want your tank to be filled to the brim then this is not for you. If you have a 15 gallon or larger tank and don't keep water filled to the brim then this is a good alternative to an expensive ATO setup.