14-18" hmm. What size tank will s/he require at their max size? The largest tank I have currently is a (roughly) 120gal. I think that may be a little small for it?
For water volume, we estimate 20 gallons per adult size fish for the large-bodied types (such as commons, comets, wakins, shubunkins, fantails, orandas). Smaller varieties would need something less, of course. More in the range of 15 or 16 gallons per adult fish.
In reference to overall tank space, your 120 gallon size tank would be large enough to house 5 or 6 comets - not just one. If you're going to keep a single comet by itself, then something like a 50-60 gallon tank would give him/her plenty of lateral swimming space from one end to the other. Remember, these are slender and maneuverable fish. They swim fast and need room for that reason. But still, one-half to two-thirds of the overall length measurement is nothing but a long, flowing tail fin.
Could s/he potentially live in an outdoor pond? My mother is planning on building an outdoor pond in our backyard in the near future and if, when large enough not to be scooped up by birds/etc, I'm sure she'd love to have a fish in it. We always loved the koi in the outdoor ponds when we lived in Japan, but that was a lot warmer weather than here in NJ. Would it be too cold here?
Yes.. Comets and other large goldfish are often kept in ponds, even combined together with larger Koi. My experience with goldfish has always been keeping them in aquariums, so I'm not able to help much with outdoor pond setups and temperature/climate details. You'll have to get more information about that from pond keepers. But that pond environment is the most natural condition these fish were bred to inhabit. Their metabolism slows down a lot with goldfish as the temp range gets lower. As long as the pond they're in is deep enough and doesn't freeze over solid, the fish stop eating completely and basically slow down to a state of sleep through the winter months until it warms up again.
As for food, currently s/he is eating Aqueon Tropical Flakes and various crumbled up Hikari pellets (sinking, algae and carnivore).
I'm not familiar with Aqueon's brand. But tropical flakes would not be well forumulated for the dietary needs of goldfish. Those are suited better for tropical community fish which have different requirements.
But I've found a few stores locally that sell the following goldfish foods I could pick up today, are any of these good choices for them (if not, what should I buy?):
Whenever I've used Tetra or Wardley which is widely available here, I notice it's a real messy food. Fouls the water much faster than other brands have used. So I use these brands very sparingly until it's gone. (Then try to remember not to buy them again later.)
To be honest, every time I start reading about listed ingredients, other content, percentages, additives to avoid, and color enhancers they don't need... it just makes my head hurt. So I cheated. I asked Flaringshutter what she was feeding her goldies one day and just left it at that ever since. Iris recommended a slow sinking goldfish pellet sold by Omega One at the time. That was good enough for me. I've not been able to find that in regular pet stores here, but it's available online in bulk packages. I also remember that Hikari has come out with some highly regarded for goldfish recently. Just don't remember what it was called. Maybe someone else will expand on this here. Or just browse through some of threads here about goldfish foods. Flaringshutter and many other more knowledgeable members have posted excellent advice and discussions recently. Say, within the last 2-3 months. I plan to dig through those threads again, myself, someday.
Aside from specific brands by name... goldfish are omnivores, so they need both proteins and vegetables and not so much added artificial color enhancing stuff. I wouldn't recommend tropical flake foods or what's forumulated for carnivores. The digestive tract for more compact body type goldfish is much less efficient. So for those varieties of goldfish, a higher level of protein passes through them undigested, where it adds even more waste to the bio-load. Because of the cramped internal organs for those fish, they are also more prone to develop blockages and swim bladder disorders. This isn't as much of a worry for comets and commons their intenstinal tract is still ''normal.''
Flakes, pellets, algae wafers, shrimp pellets, bloodworms, blanched or steamed veggies and leafy plants would give a nice variety. A lower fat content is better for goldies kept indoors as they're not being conditioned for overwintering in outdoor ponds.
Oh, I pick up Mysis Shrimp and Blackworms periodically for other fish and inverts I have, would the Goldfish enjoy these, too or no?
Yes, very much. Use as a treat, not a staple.
And on the flip side of the carnivores, I pick up various vegetables and plants for some of my fish and inverts, would the Goldfish enjoy these, too or no?
Yes.. plus they need a lot of veggie content in their diet anyway. Whatever you can supplement from the grocery store (or by growing live plants for them to eat) saves you that much more at the pet food aisle... and keeps the fish healthy.
