[Soup12]

trying to decide between getting the 2 snails for my 20g long. These snails will feed my dwarf puffers in fluval edge 12g.

the 20g long will have a carpet of java moss, java fern, and frogbit and dwarf water lettuce floaters.

Will either of these snails eat those plants?

 

[Hardstuff]

Pond snails will eat your plants. However if you have some algae growing either on the plants or the glass or substrate the plant eating will be minimal. They will mostly feed just on algae as long as there is algae. If the tank becomes algae free they can be APITA! I have to cull mine if the algae getts very low. Another trick you can try if this happens is you can feed them some boiled lettuce , but the penalty for this will be multiplication so culling works the best for me. They do a great job of cutting down algae if problems develop though.
I do not know anything about the reds though. My 2 cents

 

[dougolasjr]

I have seen what I believe are Rams eating frogbit probably due to lack of excess food.

 

[HybridHerp]

Bladder snails (sometimes mistakenly called pond snails) and ramshorns do not eat plants unless the plant is already dying and melting.

I like having them around tbh.