Glad to see other people on this site interested in Goldfish
. I happen to have 2 Goldfish
(planning to get 2 more) in a 55 gallon. I'll do my best to answer your questions, but if I can't then I have found the people at thegab.org very helpful for much of the advanced stuff.
You should actually keep that heater. Fancy Goldfish
like a steady temp of about 75F (I only have to run my heater in the winter). The common Goldfish
are more hardy with temp variations, but I do not recommend them for an aquarium. Common Goldfish
really do best in ponds or 100+ gal tanks. With the filter you have you could have about 4 fancy Goldfish
. Fish Profiles: Overview of Goldfish
Types <-- This is a good pictorial guide to Goldfish
breeds. I would stick away from anything without a dorsal. My favorite is the ryukin ^-^. Fantails are pretty but their long flowing fins can become a problem.
Now for your questions:
1+2) Sand is a great substrate for Goldfish
. The substrate needs to be either something small enough that it will pass through the GI tract unimpeded or is too large to fit in their mouths. I've never dealt with sand for substrate; I prefer large river rocks. Goldfish
can also be kept in bare-bottomed tanks. Many people also do that. But I would not use regular aquarium gravel.
3) Yes. Goldfish
love to snack on live plants, but I have found a few species that either outgrow their trimmings or they don't like. I have anarcharis, Hornwort
, and Water Sprite
in my tank. They like the Water Sprite
the most. Goldfish
are also big waste producers and all of the plants in mine are nutrient sinks (great way to keep the nitrates down). A good way to keep them from eating your plants is to provide them with fresh veggies daily; in fact I highly recommend it. Goldfish
can't survive and thrive on commercial feed alone. One way many have found to get around Goldfish
uprooting plants is to plant them in little pots. I haven't had an uprooting problem. Goldfish
are rather varied. Some people have a real problem with issues like nibbling and uprooting; others don't.
and snails... I have a troubling history with this. My Goldfish
have eaten almost every snail that can fit into their mouths. If you get one large enough not to be eaten, it will probably survive. Again; it's mostly a case-by-case basis.
5) I can't really answer to this. It depends on what you want. Do you want to watch them grow? Do you want to insure that you have a great specimen? Goldfish
will easily live for 10+ years under the right conditions, so it is not an issue of the amount of time you will have with them.
6) Things to avoid: Putting the eye-deformed Goldfish
like bubble eyes, celestials, and moors together with non-eye deformed breeds like ryukins and fantails. Exercise caution when putting commons and fancies together. Be careful of sharp decorations with most of the fancies. I had a fantail who ripped his beautiful fins on my tank decorations. Another thing to avoid is low-quality commercial foods; these can cause gastro-intestinal bloat which can cause swim bladder disease (sometimes called floaty Goldfish
I hope I was of some help! Let me know if there is anything else I can do for you.