It works for the smallest of snails, but as other reviewers have said, you need to be careful with small fish. Putting it together is a bit challenging for arthritic fingers, but once it's done it definitely works!
This device does exactly what it says. I would say to use anything other than the food tablets that come with it. Be cautious of small fish as well.
Once assembled it works great! However assembling can be tricky. I was wishing I had 3 hands, and the little trap doors kept falling out of place. I found that I had to add some rubber bands around the outside, right at the trap doors/prongs to help hold it all together.
This is a very effective snail trap!! It’s a fascinating design, that is, honestly, a bit fiddley to set up, but it is the most effective snail trap I have used. Tiny fish/fry could get inside, so take care when removing from your tank.
The only reason I give this product 4 stars is that my plecos were able to find their way into the trap even when I had it set with the smallest opening. I like the design and it is built well but be careful with smaller fish in the tank.