I think my tank is overcrowded?

You seem to have several questions here. I'll try to answer without being mean.

You didn't say what kind of "feeder fish" you have, but I'm guessing that they are common goldfish. Common goldfish can grow to be at least 18 inches long, and a foot or more is usual, so you can see why they can't stay in a bowl long-term.

One common stocking suggestion for goldfish is at least 30 gallons for the first goldfish, and 10 or more gallons for each additional goldfish. By this guide, you should have a 60 gallon or bigger tank for your four fish, but 50 gallons is close enough to that, and so much better than keeping goldfish in a freakin' quart bowl, that I don't think you need to worry about that.

If you are doing ammonia tests, and they show no ammonia, I think you must be doing good maintenance on your tank. Just test once in a while, and if it comes out OK, don't worry about it. You could also try testing for nitrate. Nitrate should gradually increase between water changes, but should never be allowed to rise very high.

Flake food is OK for goldfish. There are numerous other goldfish foods on the market (pellets, sticks, granules, frozen foods, and more), most of which are also fine. Just be sure it says on the package that it's for goldfish. Goldfish have different nutritional needs from the majority of aquarium fish (that's one of the reasons I don't like seeing people keep goldfish and tropical fish together). For example, their diet should have more vegetable content and more fiber. They also need a lot of carotenes and Vitamin C in their diet in order to maintain a rich, orange-red color.

There are numerous other fish that are adapted to cold water, but few of them are as hardy as goldfish. Dojo loaches, White Cloud Mountain minnows, red shiners, and rosey red minnows are some of the most popular. Also, many different native fish species (of course, what's "native" depends on where you live).

Finally, most filters will circulate the water enough to keep the oxygen level at or near saturation, so a bubbler is not necessary in most tanks, but it certainly does no harm, so if you like it and the fish seem to like it, I would keep it if I were you.

Its seems as though "Aquella" Didn't read your question fully. He said NO RUDE ANSWERS. Don't criticize people aquella when you don't even know the rule. Its 20 gallons for the first fancy and 10 for every other. We aren't even talking about fancy goldfish so why did you mention that? Totally irrelevant to the question. Its also 55 gallons for a PAIR of comets/commons. Not one, that's totally ridiculous. You really need to stop going by what the book says, and go by life experience. Please do not listen to anybody that has answered so far but myself or Gary C. He is the only one so far that knows what hes doing besides myself.

Now on the the question. You did a good job by buying a bigger tank. This is essential to make sure they live their life the fullest. Although 4 "feeder" fish require a 100 gallon tank, they will be fine for now until they outgrow it. This should take about 6 months to a year, then you should think about upgrading. 50% water changes a week is pretty high, but considering the tank is a little overstocked, this makes up for it and will suffice. Flake food is fine. You can also feed them pellets if you want to. I cannot stress enough, MAKE SURE you have double filtration for the tank. You want 2 filters meant for 100 gallon tanks as goldfish are VERY messy fish. I wish you the best with your goldfish, it seems you are off to a good start after moving them out of the bowl.

Unfortunately, you've got a lot of bad answers here. Common sense can help you figure out what won't work and what will.

Let's go through a couple problems in the answers you've so far received:

-You do not need a heater for Comet Goldfish.

-4-5 fish will not be OK long term in a 50 gallon, and fish do not grow to their aquarium size and then live a happy life. Instead, the outer body of the fish stops growing, while the organs continue to grow until they literally burst inside the fish. It's called stunting, and it's no fun for the fish.

-Just because someone keeps 8 Comet Goldfish in a 75 gallon does not make it OK. And the rule is not 10 gallons per Goldfish. It's 55 gallons per Comet Goldfish. Minimum.

The rule is also not "30 gallons for the first goldfish, and 10 or more gallons for each additional goldfish". That is the rule for Fancy Goldfish that are not nearly as large or active as Comets.

Here's what your fish WILL need and you should know:

- Comets grow to be 15-24 inches long. Given good water quality and proper space, they should grow quickly. A well kept Comet should double in size every few months. If that's not happening, you've very likely got a water quality issue.

- A bare minimum of 55 Gallons is needed for one full grown Comet. Really, nothing under 75-100 gallons should be considered. For 4, I'd suggest about 250 gallons minimum, though these fish are suited best for ponds.

- All Goldfish need very heavy filtration. A filter(s) rated for at least double the aquarium's volume is required.

- You really need a good liquid test kit. Strips are not accurate. API master test kit is a good one.

Test weekly, just before your water change for Ammonia, NitrITES, and NitrATES. If your Ammonia and/or Nitrites read above 0ppm, you need to perform more frequent water changes or up the filtration, or decrease the amount of fish, or all of the above. Nitrates should be under 40ppm.

PH, unless it's off the charts is really not worth worrying about. Any hardy aquarium fish can handle PH outside the ideal zones, and trying to correct it will be far more stressful than letting it be.

So, for right now, assuming you've got filtration rated for at least 100 gallon, your fish should be OK. However, in the near future, you're going to need to upgrade or look for a fish pond for them to live.

Also, while there are other cold/cool water compatible fish, such as Whether Loaches, Danios, and Minnows, Goldfish should be kept only with similarly sized and tempered Goldfish. (No mixing Fancy's with Common/Comet/Feeders.)

Good luck.

Here's some good info on all Goldfish, with some good info included on Comets:

http://www.aquariacentral.com/forums/archive/index...

Edit @ um, "fishexpert". I did read the question, I am going on real life experience, I'd never keep a Fancy in a 20 gallon, I think 30 gallons a reasonable size, I mentioned it because it was advised in another answer as a good rule for Comets, which it isn't, and um, have you ever seen a full grown Comet? Let's say for arguments sake, that these particular Comets stay small at 15". A 50 gallon isn't even 40" long, and you want to put not one, but 2 of these fish in there? Sure, they'd technically fit, but they certainly wouldn't be able to move around much. What a life.

I think that you probably don't have any actual experience with these fish, and I think that you should examine your knowledge (or lack thereof) before calling others out.

4 fish in a 50 gallon tank is nowhere near overcrowded... What type of fish are you using? Probably small gold fish like comets... You can have easily 30 in a 50 gallon tank so long as you keep up with the water changes... More fish means more food which means more waste. But as long as you keep your filters running and water changes going, you will be just fine. Goldfish put out a lot of ammonia, but it's not that big of a deal (not so much that 4 in a 50 gallon tank is an issue anyhow)

Edit - to address your other questions.. Fish flake is perfect, no need to feed them anything else. Gold fish don't need a lot of oxygen, but it adds a cool look to the tank with the bubbles. I would suggest dumping the feeders and getting about 10-15 fish you like for your 50 gallon!

Edit 2 - I guess I never considered keeping the feeders to full maturity... I kept 10 or so alive for a year and a half till I moved in a 30 gallon tank...

You should not ever put 4 feeder fish in a 50 gallon tank! You should just have plants and rocks in there.

Your tank is not over crowded. I have a 75g tank with 8 comet/common goldfish. The rule is 10g per goldfish. As long as you have a filter then it's fine. These feeders produce lots of waste after eating. Yes, goldfish (only feeders) do well in cold water tanks. Flake food is what i feed my fish everyday, because i tried feeding them pellets but they can't eat them. The brand I use is Tetra Fin Goldfish Flakes. My fish are about 3-4in. I've kept them for about 9 months. I used to have them in a 10g, and found out that the tank is too small and won't fit 8 feeders. I bought them as $1.00 for 8. Don't buy a used tank, its not worth it. Stay with the 50g. If people say buy a heater, don't get one. Feeders include comets, common, and shubunkins are all coldwater. Only fancy goldfish require a heater, because they need a certain temperature.

Hope i helped :D

The 4 fish should be fine in the tank but they won't grow. If you seperate them, they'll grow larger. But you also risk them having issues with the change. A few other fish do well it un-heatered water, go to a Petsmart. A heater is a good investment, you can get more fish and they will do better. Fish will do fine on flakes, but you can feed them mealworms as a treat.

seems fine to me a 50 gallon tank for feeder goldfish is a great thing!

go with your in stincks don,t beleave every thing you read but if you go on the web tipe in what your trying to answer you will find your in fomation you requir soory i can,t give you any moor info

Let nature figure it out. the weaklings will be weeded out