You never said how wide this pond is, but it sounds on the small size for goldfish. The single tails are going to out grow the pond. The fancys will
They eat very small snails and it is part of their natural diet. Bottomline, snails are good for them and they love them to death-literally!
Both the Discus are looking pretty....
Buy a larger tank for them, if you can.....
Welcome to the forum.
Hope you will enjoy your stay here and discussions on the board.
What lighting do you have on the tank right now and what do you consider moderate light? My first thought would be that it's a lighting issue (considering