Well the best thing to do first, when they have outgrown their little tanks, you should get those big tanks with filters. You should get a big one because it would give your goldfish a lot more room to swim.
The only time a goldfish is eaten by another goldfish is when the parents breed and they have eggs.The eggs hatch then the parents eat them because they mistake them for lava or something.if ur fully grown gold fish is eating another fully grown golfish then its not a goldfish at all!!!!!!!!CHECK FOR THE BREED in other cases.
A beta or goldfish might be able to grow
about 10 or 15 depends on how big they are
If they are fancy goldfish (the plump looking ones) then 6 or so would do well in an 80 gallon when fully grown if they are common goldfish, then 2 maybe 3 when full grown would be ok as they reach a whole foot long! This may seem like its not many fish for a large tank however goldfish are real poo machines and good filtration is a must.
A fully grown goldfish can weigh up 10lbs (4.5kg) but that is rare. However, it's not unrealistic for a goldfish to be 5lbs (2.25kg)
Goldfish need plenty of room to swim around and get very large. In a 1000 gallon pond you could put 25-50 goldfish just keep in mind that goldfish grow very large and need about 20-30 gallons each when full grown.
yes you can keep your comet goldfish in a goldfishpond.In fact having them in a pond is a good idea, as long as they are not subjected to herons and other predators, because this variety of goldfish gets very large: up to a foot! :)
It takes 2 or 3 months for a houshold pet goldfish to mature, you can tell if it's a female by that time because they will have some white speckles on their lower fins. Plus, though the common goldfish lives for about 2 days in a bowl, but if you get a 10 gallon tank for it and feed it every morning and night until it's mature, then once a day when it's mature, it can live for a long time; I had a goldfish that I cared for ( the pet goldfish not pond goldfish), and it lived for 9 years! ( It just died :( ) But look for red and/or white spots, split fins, or enlarged eyes as these can be deadly but simply buying medicine from the pet store will save your pets life.
The maximum size of a fully grown common goldfish is almost two feet (60 cm) in length and weighing close to ten pounds (4.5kg). Most goldfish won't grow that large but can easily grow to around 12 inches (30cm) and weighing five ponds (2.25kg). A goldfish will never grow to its potential if it is placed in tank too small or in less than ideal water conditions.
Some common breeds of goldfish are: the Black Moor goldfish, the Ryunkin goldfish, the comet goldfish, the common goldfish, the Calico Fantail goldfish, the telescope eye goldfish, the bubble eye goldfish, the pearl scale goldfish and the Oranda goldfish.
Having your goldfishes tail turn white could mean your goldfish is sick but it could also just be new tail growth.When goldfish grow new tail tissue it may appear white or grayish.This usually happens when a goldfish isn't fully grown .If it is new tail growth than it will be on the end and tips of the fish's tail not the whole tail.
Give it time, goldfish grow very slowly. It may take up to 3 years for a goldfish to reach adult size. Your fantails probably have grown, it's just been so subtle that you haven't noticed. Another way you could get them to grow quicker is to, instead of feeding them once or twice a day, feed them three times a day. Small goldfish's abdomens can't hold as much food at a single time as say a larger goldfish, so feeding them plenty of small meals throughout the day, will ensure they are getting plenty of nutrition.