How do I keep telescope-eye goldfish?

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Jeremy Gay helps a reader choose a tank to keep telescope-eyed fancy goldfish.

Q: I would like to set up a tank for telescope-eyed fancy goldfish. Please could you advise me on tank size, care and tank mates. My plan is for Calico telescopes, Orange telescopes and Black moors. Will this work?  

SAMUEL DAY, VIA EMAIL

A: Jeremy replies: Telescope eyes are straightforward fancy goldfish to keep and their care is the same, regardless of colour. They can get to about 20cm body size (not including fins) so require a tank of at least 120x60cm for three adults, long term. Depth isn’t important, so a 120x60x45cm open-topped tank would be nice, which would allow you to also view them from above. Ideally it would be filtered by an external power filter of 1000 lph or more, with an airstone connected to an airpump. Use small, round, inert gravel that the fish can dig into and mouth without it getting stuck, and decorate with some smooth pebbles and maybe a piece of water-worn wood. Either go for no plants, hardy plants like Anubias which can be attached to the wood, or some non-spiky plastic plants. Avoid anything sharp as it may damage the fishes’ eyes. Room temperature tapwater treated with a dechlorinator will be fine, and mature the tank by fishless cycling it first. 

Feed the fish on sinking goldfish pellets like those from Hikari, Vitalis or Tetra. Change the water regularly (50% a week if you can) and add some activated carbon as goldfish tanks can smell a bit. Other varieties such as Ryukins and fantails are just as easy as the telescopes and can be mixed with them — telescopes are basically fantails with protruding eyes. True British Veiltails are slightly more delicate because those long tail fins are susceptible to infection, so are probably best avoided in this case.