Sorry to interupt this conversation,but by "fancy tails",do you mean "ryukins" "black moors" "orandas" etc....???
I have some of the above,and would be interested to know what other types of food they can have apart from the normal flake food and the occasional frozen brine shrimp.
Bloodworms,daphnia,tubilex worms,river strimp,frozen,peas,broc,savoy cabbage,lettuce,cucumba,algae tablets, brown bread now and again,rice,banna,apple,floating pellets.
Once a day with just flakes is not enough as you need to feed them other variety of food or they will be prone to dropsy, and swim bladder problems they need frozen products and veg in there diet.
I see.One of them does seem to have problems in keeping his "balance" sometimes.
E.G. floating upside down to the top of the tank,although he does eventually "right himself".
Should the lettuce,cucumber,bread etc...be broken up into "bitesize"pieces for them first? or maybe just put in a "lump" and encourage a "free for all"
Try your fish with some shelled peas and you will need a swim bladder treatment, it's hard to cure if the swim bladder desease has progressed, cucumba put in boiling water for a minute remove seeds and weigh it down with a weight and rubber band.
I feed the goldfish twice a day and I hold the flakes under water so they're not on the surface because Dennis (orlanda) eats like a mad quick frantic thing and then get's wind. I also give them frozen food every now and then and peas etc... and they eat my plants!