Number of fish for a 55 gallon tank.?

Question

I have a freshwater community tank that's in good working condition. I currently have ~20 of the usual species (Danios, small tetras, platys, 1 cory cat, 1 clown loach).

Is anyone aware of a formula to be used to determine how many (average 1" or something to that extent) fish my tank can accommodate? Size is the current "standard" 55 gallon.

Thank you kindly.

Answer 1

The best way to stock a tank isn't about any rule, but research and comon sense. You are the one with the tank, you should decide how many more you can have. Experience will show you more then anyone can tell you here.

With smaller, peaceful community types you can fit quite a few in a 55 gallon tank. You don't want them crammed in like at a fish store, which only sells them, and you don't want more then you can handle with aquarium maintenance - too many and you'll find the aquarium degrading over time, including visible waste and invisible toxins, like nitrates. More fish also generally means quicker algae growth. One diligent person might be able to go with 50 small fish, while another less diligent person might be best to stick with closer to twenty. In the end lighter stocked tanks are easier to keep.

The inch per gallon rule is vague, but it's not a bad starting guide for those who keep smaller fish like you do - excluding the clown loach, and normal shaped tanks, not tall ones. Since most of your fish will reach a couple of inches long in the end, you can figure that you have a bit of room to develop some proper schools for your current fish, but shouldn't add too many more.

Also consider the grown size of the fish. Cory cats stay very small and you can fit a whole bunch in there (and you should get more since they are are schooling fish and do much better this way). Clown loaches on the other hand can reach nearly a foot long and even one will ultimately grow too big for the tank.

Answer 2

I was counting in my head while reading through your list of fish. Using an average length of a half-way grown fish estimate and allowing for the rule of 1 inch of fish per 1 gallon of water, with what you have now, you're already up to about 48 inches of fish and they aren't even all the way grown yet. I know how much we all want more and more fish because they're so beautiful and fun to watch, but, for the health of the fish, we need to learn some restraint and know when to say enough. The elephant nose would be okay with fish equal its size and larger, but the smaller fish will be dinner in no time, plus, they can grow to 9 inches, so probably not a good choice. You could get away with a dwarf puffer as they only grow to 1 inch in size, but keep an eye on the growth of the rest of the fish and using the 1 inch per 1 gallon rule, do your math and when they start hitting about 50, it's time to think about a larger tank, because these fish will eventually exceed the allowable amount of this tank. You need a good selection of foods for this group of fish. Cichlids have special foods and feeding requirements, catfish have their own special foods and feeding requirements and then they all need their special treats of brine shrimp, krill, blood worms, etc., spirulina, fresh fruits and leafy veggies.

Answer 3

The extremely general rule of thumb is 1" of fish per 1 gal. of water. In a tank, you have to subtract the space the substrata, decorations, plants, heater, etc. displace to figure out how much actual water is in the tank, and most of us do not fill our tanks up to the very brim so you have to subtract however many gals are not there between the water surface and the rim. A 55 gal. probably won't have 55 gals of water in it. And some fish need more space to themselves to stay healthy. Also keep in mind that unstocking is always better than overstocking.

Answer 4

Experts have told me to stay around 1 average (1") fish per gallon of water. I think with a tank that big you don't have to be too exact, but you should try not to put in more than 55 average size fish. More specifically, the "one inch rule" says that you should have one inch of fish per gallon.

Answer 5

i have heard that to every 1 us gallon of water, 1 fish. now i have a 10 gallon tank and i have a lot more than ten fish, but over half of them are small fish. so, if you are wanting to get small fish like the mollies, guppies, platys, danios and tetras you could put a lot more than 55 fish in. but if you are using bigger fish like the koi and chiclids stick to 55. fish also grow with the size of their environment, if it is crowded in the tank, they wont grow as much, hope this helped you out and didnt confuse you too much. if you have any more questions feel free to message me, i have been running my tank for about 4 years straight and half 5 of the original fish.

Answer 6

With fresh water you have alot more freedom, Than say Saltwater, It depends on the type of fish, An Oscar for example which eats like a pig will destroy the water quality faster that say a gold fish, Also the type of filter your running will make a big difference in how many fish, Check your water and make sure the ammonia doesn't rise, or Nitrates, Sounds like what you have is fine, IN saltwater they say an inch of fish per 10 gals, but like I said with fresh you have more flexibility

Answer 7

Well looks like alot of bad advice out there today. As a rule you can have 1 inch of fish for every 5gals of water.
Depending on what type of fish you have you may need more water per inch, dirty fish the more water you need.
This rule changes with salt water as salt water holds less oxygen.

Answer 8

It's 1 inch of fish per gallon, so you are doing ok with what you have, I wouldn't add to many more fish unless there adult size is 2 inches or less. Good luck!

Answer 9

I have 3 cory's, 11 neons, 3 black skirt tetras, 2 albino skirts, 5 red rosa tetra's and one medium discus and probably will put another discus in.

Answer 10

If they are normal sized fish and not too large it can hold about one per gallon...or that's what people at pet stores have told me..but I think you should give em a bit more room personally...