View Full Version : New Comet!!! How fast will it grow?

06-07-2010, 09:24 PM
I am very familiar with exactly how big my fish should get but have yet to find anywhere exactly how long it will take them to get so big.

I currently have a 65 gallon tank with a Shubunkin and a Black Moor that are both about 3-3.5 inches including their tail fins. Today I added a 13 cent comet goldfish (picked out the cutest and healthiest looking one) and it is probably around 1.5 inches including tail fin but I haven't measured it yet to be certain.

I feed my fish TetraColor sinking goldfish granules and live black worms. I've noticed that my fish look much healthier when I feed them live food. My dojo loaches actually had a growth spurt when I started feeding black worms.

Moving on, though, if I keep my water in optimal condition and continue the same diet, how quickly will these grow?

I'd just like to know how long I have until I need to get a bigger tank. Three 8-12 inch goldfish will not fit very happily in a 65 gallon tank, right?

And before anyone mentions it, my black moor gets plenty to eat and does not have to compete with the other fish at all because my fish tend to come to the surface when they know it's feeding time. The black moor is actually quite playful with the other fish as well.

Little Embers
06-09-2010, 03:02 PM
How fast a fish grows depends on many variables, such as...temperature, water quality, diet, how often/much they are fed, stocking levels etc., so it is hard to give a specific time frame.

I think you should be able to see/judge how fast your fish are growing and when to get a bigger tank for them. They do tend to grow quite quickly when juveniles.

06-10-2010, 01:56 AM
So nobody can even give me a ball park figure? Anyone on here with goldfish able to tell me how fast their fish grew? My goldies all seem to be growing very quickly but does their growth slow down at some point? I know that they never officially stop growing.

06-10-2010, 03:16 AM
We do have a few members here that have them. I have never kept them.
You will get more replies soon!lol
My guess is they do the faster part of their growing over the first two yrs.That does depend on weather or not they re getting a great diet and have a large enough tank and proper care.
How big are yours now?

06-10-2010, 01:30 PM
With that size tank (assuming there aren't other/many other fish in there) you should see quite a bit of growth, probably up to, but possibly over 75% of their final length within the first three years. Though, maybe it's just my fish, but my females seem to grow a little bit slower.

Just keep up with great diet, and lots of room in the tank (for the best length, don't add ANY more goldfish.) Don't forget to add vegetable shavings once in a while as well, since Goldfish are scavengers and grazers primarily. You've got the scavenging part down, but the grazing needs to be addressed.

As for when to upgrade them, I'd aim for somewhere around when the fish hit seven to eight inches. This could be anywhere from 1 to 4 years in the future - I can't give you a more specific time because some goldfish, due to breeding, just grow slower or faster than the expected averages.

Very glad you are indeed considering upgrading them in the future. Too many people in the world think that the "20 gallons for the first, 10 for each additional goldfish" is plenty. If you wouldn't put your 14'' Oscar in anything less than a 75 gallon, preferably a 125 gallon, why would you even consider putting your 12''(and they can and will get larger with the right variables) comet goldfish in anything less than a 50? And yeah, sure, some goldfish only get 6'', but that's still at least 30 gallons needed for the smallest.

Bah. I'm going to stop ranting now while I can. lol. Whole above paragraph summed up simply; I'm proud of you. xP

06-10-2010, 05:56 PM
My comets hit 7-8" in about a year, kept in rather cold water most of the year.

06-10-2010, 06:01 PM
Today I added a 13 cent comet goldfish (picked out the cutest and healthiest looking one) and it is probably around 1.5 inches including tail fin but I haven't measured it yet to be certain.

The 13 cent fish grow the fastest of all of them!

06-10-2010, 10:35 PM
Wow, thanks so much guys! First, I got the 13 cent fish hoping it would grow faster since it is only half the size of the other fish right now. My shubunkin is somewhere around 3" as is my black moor. That's including tail fins. The comet is only about 1.5 inches or so including tail fin. The only other fish in the tank are bottom dwellers and my tank is a tall, not a long, so the goldies pretty much have most of the tank to themselves.

Care to expand at all on the grazing and scavenging bit about the goldfish? I noticed that my goldfish scavenge the tank bottom just as much as my bottom dwellers do, if not even more so. My tank is very well planted with different types of plants (wisteria, cabomba, contortion val) but my goldfish don't seem to really eat the plants, luckily. They pluck at them between feedings but never do noticeable damage to any of the plants. My goldfish also seem to be good about keeping the driftwood algae trimmed down. I tried feeding them some broccolini and zucchini when I first got them but they didn't seem interested. Maybe now that they are slightly bigger I'll try again with the fresh vegetables.

I held a ruler up to my tank to judge how big the fish could get before they just looked absolutely ridiculous in the tank and my judgement was 6-7 inches in my 36Lx18Wx25H 65 gallon tank.

All of your comments are greatly appreciated! Thank you!

And yes, it is very unfortunate about the number of people who buy goldfish with no consideration for their adult size. I, however, tend to spoil all of my pets. My goldies seem much happier having a third fish in the tank and when I upgrade I'd like to get maybe two more.

06-10-2010, 11:12 PM
As you said, you've seen them scavenging along the bottom just as much as bottom dwellers.

Goldfish will pretty much try to eat anything that looks edible, and just spit it back out if it's not right. Taste first, think later. =P Thus, while they do have a pretty decent interest in top-of-the-water and water column bugs (or in the aquarium, flakes/pellets), it's much more common to see them scrounging around the bottom, tasting everything they can find, swallowing what's good. Well, except in ponds where the carp/goldfish/koi/etc type have learned that humans will give them more food. Then they're nearly always competiting for a spot near the top.

I'll PM you a link that has a lot more information about the diet of carp-like species.