So I recently switched to a herbie style overflow with a return going up the back of the tank and over the lid back in about 3 weeks ago. This morning I awoke (8:30am) and noticed a nerite snail about and inch down the main overflow drain and immediately panicked. Not really up and at it I accidentally dropped the snail while lifting it up out of the overflow. The drains are 1in with a 1in bulkhead which goes down to mutiple elbow's down into a gate valve. I ran the tank and sure enough it was clogged, the snail was appox half of a inch. The water went up to the emergency overflow and started draining. However I had class this morning until now when I got home. I came home and had my canopy off the tank and the return off, not thinking to check my normal settings to see if the pipe was clogged I turned the gate valve completely open, usually its about a quarter shut. I don't have my settings marked, however with the gate completely opened and my return running at normal the water does not seem to be restricted, actually the water level is staying right at the first pipe main drain making it seem as there is nothing in there at all. And when I got home there was a nerite snail in the overflow area on one of the walls, however when I turn off my return my water line drops about 2inches to the return until it sucks air, I doubt a snail could get over that overflow box with no water 2 inches up and then another 6 inches down until the water line by the first pipe. The snail looked smaller than the one this morning however I was groggy and not paying attention. If my flow isnt restricted and I have tons of flow going out of my pipe into my sump with my gate completely open and also that flow should be enough to blast a snail past the pipes should I be worried and take all my plumbing apart? Did i get lucky and the snail climbed out? If worst came to worst I always have the emergency drain. I think I got really lucky, I also went to home depot and got a strainer both pipes. Flow is blasting out of the drain into the sump and there seems to be no restriction. I should have not touched the gate to see if the water would rise to the emergency. Worst comes to worst I find a shell a couple months down the line when doing maintenance. Im just really worried I normally dont ramble like this but in an emergency Im just trying to get this out there ASAP.