Yikes!
I bought five assassin snails and put them in the tank with the loaches. The loaches immediately tried to attack, so the snails are now waiting in a bowl with a sponge filter for the loaches to be re-homed on Tuesday.
Probably if the assassins had been there before the loaches and had a chance to burrow under the substrate they would have been fine.
Most, (but not all ), of the snails are gone thanks to the loaches. The assassins should, I hope, keep things under control.
I am amazed at how much damage those snails did to my plants. I shouldn't be--knowing what terrestrial snails can do!
Thanks all, it's continuing education!