Veggie Assassins?

[Ardvark]

I've got me a 64 ltr tank with 14 Guppies live plants and 3 Assassins.
I got the Assassins because of a pest snail problem I have from me live plants and they are one of the best ways to cure that problem without getting rid of the plants.
Today I was doing me weekly water change and sucked up literally a couple of dozen pest snails from the wall of me tank.
Now either I have vegetarian Assassins or 3 of them isn't enough for the size of me tank.
Questions
1) What do members think would be the correct amount of Assassins I should have for the size of tank? 
2) How long do members think it'll take to control the pest snail problem?
 
                                                                                            Al

 

[Mamashack]

I have 4 assassins in a 60L tank. They don't clear the pest snails overnight especially if there are loads, but they will clear them eventually. What you've got will probably suffice - just give them time to do their job.