I have assassin snails in every tank breeding and grow on tank.
I have never observed any activity remotely connected with assassin snails eating eggs.
In fact I have placed Assassin snails in fry traps with eggs and seen them eat only funguses eggs.
The problem of snails is a reoccurring issue on this site and quite rightly gives many fish keepers distress and problems.
Let us first examine the snails and the reasons for ending up with “Infestations “.
I am going to make no attempts to identify the 10000 of different types of snails and the various breeding habits of them.
From my point snails are 3 types Assassin snails that are no problem and can be sold quite easily once they reach an unsightly amount. Malaysian trumpet snails and little round ones.
Malaysian trumpet snails are the main problem for most fish keepers they are I believe a live breeding snail and spend most of the day buried in the substrate.
The snail is mainly active at night and will be found all over the tank during the night if you suddenly turn the tanks lights on late at night.
A small amount of these snails is in fact beneficial to most tanks; they being substrate based will move the substrate about allowing gas from decomposing waste to disperse.
Sadly like most things in nature they are not interested in what we as humans want just interested in 3 things sex, kill and die.
So they have attributes that aid them in this task, firstly as the are live breeders they are not venerable during an egg stage, they develop fast and become a hard shelled organism fast. Almost impossible to crush and averse to being destroyed. Once they have developed the hard shell they are almost bomb proof.
You can remove all your substrate along with the snails and dump it in a bucket in a dark and dirty corner of your garden just use one cup full of this substrate 20 years later and wham an outbreak of snails.
I stupidly used them to keep sand based substrate clean thinking I could control them.
The main reason for them becoming epidemic is food or more correctly over feeding your /our fish.
They will after time also create problems and deplete, by eating most organic material producing nitrate on a scale that will cause problems.
Assassin snails are about the only way to control them , one main problem is should you have them in large amounts the assassin snails will hunt and kill in large amounts and you end up with snail shells in every part of the tank thus your PH / Kh / Gh may become unstable.
So I advise a total clean out and just a few assassin snails to keep on top of any out breaks
Next the little round things
Easy to control just crush them. Very therapeutic but sadly quite cruel.