Having issues with my golden mystery snails and plants

[Retired Viking]

I have two golden mystery snails in my 55 gallon planted tank. They are an inch tall and little over an inch long. At first I had very little trouble with them and they seemed to do a good job cleaning. I added 2 cory and 5 shrimp to help clean the bottom. Then I noticed some of my plants were being damaged by the snails. They went after some jungle vale, anachris and moneywort. I added more food at feeding time and picked up Tetra cory wafers and pleco algae wafgers and added those. At first the snails seemed happy but now one has stripped a hornwort plant completely and half of another. I caught him red handed and put the snail into my empty forty gallon tank that I just started. Then this morning I found a new moneyworth plant I had just planted a few days ago destroyed. All that was felt on the bottom of the tank was the metal band and a few striped stems. The leaves were floating in the tank. I have put plenty of food on the bottom in fact it is getting a little messy and I plan on doing a good vacuuming later today. Any suggestion? I am tempted to try making some escargot, I heard it is delicious.

 

[Essjay]

I have read many times that brigs (Pomacea diffusa) only eat dead plants while canas (P. canaliculata) eat living plants. But I can't say for sure if this is true from personal experience as the EU had banned the import and spreading of all apple snail species.

Do you know which species your snails are? There are some diagrams on this site under 'species' in the menu on the left. https://web.archive.org/web/20180502212717if_/http://applesnail.net/ [It will take longer than usual to load as the site no longer exists and I had to link to it via Wayback Machine]

 

[Retired Viking]

Looking at the diagrams I would say it is a diffusa. He was actually eating one of the wafers when I piked him up.

 

[Retired Viking]

From the number of leaves floating in the tank I wonder if the snails just broke them off while climbing up the plants.