Yep, a freshwater puffer is a misnomer, and they are only freshwater
....
freshwater types.

Thanks for your response, but my question had nothing whatsoever to do
with the puffer. The puffer is fine in the 29 gallon freshwater tank,
and it has been for years.

My question is about the Apple snails (also known as "(colored)
mystery snails") in my SECOND 6 gallon Eclipse tank that I use for
raising feeder pond snails.

Because the Eclipse tank comes with everything built into the lid, the
lid has a HUGE CONVEX HOLLOW DOME shape that EVIDENTLY is a great
substrate for Apple snail egg sacs.

If the silly Eclipse tank was like my 29 gallon tank, with a flat
cover just above the water's surface, the Apple snail population would
be self controlled because the snails would have no place to attach
the eggs.

I'm looking for suggestions about how to control the Apple snail
population. The pond snails reproduce quickly enough to satisfy my
puffer feeding needs, and so I don't need hundreds of small Apple
snails too.

Thanks --
TEd