I sat down to type, and it all went out the window,LOL.
<needs a brain pill>
Keep the water CLEAN, snails don't "like" nasty butt water.
Plenty of food is a must- Give (as was suggested) some bog wood and plants- whatever, just give things they can crawl in/under and lay their eggs on.
Filters are good and all, but snails can die from them. They get on the intake part and their bodies are sucked out of the shells,ew.
Maybe you can put pantyhose over the intake.
Or just do regular water changes and not have a filter.
I've noticed with my snails- they all have their own personalites.
Some like laying eggs at the water line and others like laying them on leaves/or the gravel.
My guppies eat baby snails with relish. So I'd be wary of adding them to the tank.
HTH's!
Edit-
If you have the room- Put a barrel outside or a tub- whatever you can find that holds water. Get some snails ( pond snails ARE safe if raised in a clean inviroment.) plunk them in the tub with some plants (hornwort-things you can find cheap or free) leave them alone. They will breed like little bunnies! Just lift plants out when you're ready to harvest. Pick or shake some snails in a bucket of water. Put them in a clean tank- feed good foods and do regular waterchanges. Then feed to your puffers. Remember, you are what you eat. You can feed a snail to a puffer, but, if that snail hasnt been fed good foods- it's almost worthless.
After time it will become routine and you wont notice the "hassle" of moving snails around.
] Try not to se any meds and make sure your tank gets lots of light and you may also want to add bogwood and java moss because they help snails breed.
