I wish you the best of luck removing snails. I had bladder snails that hitched a ride into my tank on some plants well I finally got them taken care of and low and behold ramshorn snails appeared I didn't try removing them. I'm sure the snails all had a good laugh about that one 😂 My point is that while its not impossible to remove all the snails it can be hard so don't be discouraged if it takes awhile to remove them all.