Is it ok to buy Assassin Snails on ebay?

[spekulatius]

And how many do I need? I've got a 125 litre tank, I already have 2 assassin snails but also loooots of other snails. There were under control but we went on holiday for a week and left a holiday food type cube in the tank and now got loads. The assassin snails seem to be on each other a lot, is that normal? I've now ordered an automatic feeder thing, I think I will use it all the time to make sure I don't overfeed. Need some more plants too so I guess I will be getting more snails with them......

You could get a couple more but the influx of pest snails seems certainly down to your habit of over feeding rather than anything else.

You don't need to use a holiday block - all they do it foul the water. Avoid.

A week away is fine to suspend feeding completely if your tank it's mature and well planted. The fish will be fine.

A timed feeder is good for longer periods but I wouldn't ever use one long term. There is always a risk of it getting stuck in the down position and dumping too much food in if the battery runs out. It doesn't keep the food as fresh as it is in the tub either.

In any case, feeding time is an important time for you to assess your fishes' health and appetite. Don't leave it to a robot. Just be disciplined on what you feed and how much. For most community fish, feed twice a day small pinch of flakes - feed only what is completely consumed within 2min. If you have catfish or other bottom feeders you can feed sinking algae wafers occasionally but they should be gone in an hour ideally.