Salvinia. What's occurring?

[The_storm]

I've had Salvinia in both of my tanks for some time now.
One is a superfish Scaper 45 shrimp tank for CRS and the other is a fluval roma 240 Scaper community tank running of hard tap water.
Until last week I was giving and throwing away tons of the stuff every week, from both tanks. Today I barely have enough to fill a tea spoon. It's all nearly disappeared. Can anyone offer an explanation as to why?
Nothing has really changed in either set up except for the addition of apple snails, are these the culprits?

 

[sparkyweasel]

the addition of apple snails, are these the culprits?

That seems likely. Mine used to eat a whole lettuce or a whole cucumber in a day between four snails. And a batch of 30-40 babies could eat a lettuce in a day.

 

[The_storm]

Lordy! I wondered why they'd grown so fast!

Does anyone want some apple snails or know a nice garlic butter recipe?

*Joke

Thanks