8 comments to “How many community fish in a freshwater aquarium?”

1. Keri D wrote:
   15. June 2008 at 4:44 pm :

   I’d put about 7 of each species cause they are community fish and stay fairly small

2. brianjack_99 wrote:
   18. June 2008 at 9:20 pm :

   The key to a good freshwater tank is the plants. Neons are cool—they like slightly acid water—6.8-6,6, but you can drive yourself nuts trying to adjust the water all the time. Relax. Grow some plants. Get the water moving with a power head, think like mother nature—change 20 percent of your water weekly. if the plants are hapy—-everyone is happy. Alkaline is easier—and White Mountain Minnows are better and funner than Neons—and not hard to_99 and will give more advice—all the best, B

3. tikitiki wrote:
   19. June 2008 at 8:11 pm :

   Honestly, stay away from the neon tetras. They’re just so unhearty, and die very easily, and for fish that die easily, they’re not cheap lol. If you do go with a neon, try to find the cardinal neons, they’re supposedly a bit better then the regular neons. Most tetras I can think of prefer to be in a group/school of at least 3-5. And the same with cory cats, at least 3 of the same kind, ie: all albino, julii corys, etc. So keep that in mind when you buy them. And if you have the option to go with a larger tank, like the 20 I would. Once you add the gravel and decorations, it’s no longer a 20 gallon tank.
   Usually with tropical/community fish, it’s safe to use the 1 inch of ADULT size fish per gallon.

4. Venice Girl wrote:
   21. June 2008 at 8:32 am :

   For fish that stay small like that, you could put in about 7-8 fish total, whatever the mix, for a 15 gallon tank. For a 20 gallon tank, you could put in a total of about 10 fish, whatever the mix.

5. Jose R wrote:
   24. June 2008 at 8:33 am :

   A dozen each of these fish would be OK since they do not grow bigger then 1/2 an inch if that much. Plus they love to school together. The best results with tetras are lots of water changes, pH reading towards the acidic side but not extremely 6.8-.6.7 PH. They love to each flakes and I had very good luck with the Omega Food line. I crush it up nicely and feed. They also do wonderful when in decorated tanks such as rocks, tall plants, some water current and warm water. Surprisingly they also seem to enjoy active top tank swimmers like zebras. it makes them think they’re being fed all the time.

6. sgc1215 wrote:
   27. June 2008 at 11:01 am :

   Generally, you can have 1 fish per square inch of water (something specific to your own tank). Since you’re planning on smaller fish you can probably get away with a few more than that. You should go with at least 5 of each kind of tetra because they’re community fish. Cories should have have at least 2 or 3 of the same type as well. As for those who don’t recommend neons, I find them easy to care for. They enjoy warmer water (76-78 degrees(F) is ideal) and frequent water changes. Good Luck!!

7. sonicachic311 wrote:
   29. June 2008 at 2:22 pm :

   In case you haven’t heard, there is this stupid “rule of thumb” in the aquarium hobby that you can keep 1 inch per gallon of water. Let me start by explaining why that rule should be ignored completely.

   Consider a 3 cm (1 in.) Neon Tetra and a 3 cm Goldfish. In terms of waste produced and body mass, it will take about 20 Neons to equal that 1 Goldfish. Also consider a 1 in Pink Kissing Gourami. The Pink Kisser is just a baby while the Neon is an adult already. That Kisser has a much higher metabolism and therefore will eat more and produce more waste. Also, the Kisser has much more body mass than a Neon. The in./gal. rule is meant to apply to small fish at their adult size, such as Neons, Cherry Barbs, Cardinal Tetras, White Clouds, and Zebra Danios. Do NOT use this rule for any fish which is bigger than a Neon. Not even for a Platy or a Swordtail.

   Now that you can see what I’m talking about, let me explain how many fish you can comfortably fit into your tank. The most important consideration is that you are doing regular water changes and have the appropriate biological filter for your tank size. Provided you are doing the appropriate maintenance and have the correct sized filter, then you will probably never have problems with water quality, regardless of how many fish you put in the tank.

   The important considerations are aggression and swimming space. You should never put a fast swimming schooling fish in an aquarium smaller than 50 gallons. Many hobbyists assume that they are losing fish mysteriously because the tank is “overcrowded.” In reality they are just not giving the fish the appropriate swimming space. When packed into a small tank, “fin nippers” will become very territorial and create stress on your other fish. This is what is resulting in the mysterious fish loss. And it is not related to water quality.

   OK, so how many fish? To be honest, there is not a limit. As long as you are putting the fish in the appropriate size aquarium, you will be content with the fish load long before you have reached the biological limits of the tank. I have kept 40 liter aquariums with 30 fish and 200 liter aquariums with 100 fish. The catch is to provide the correct maintenance and be smart about what fish you mix together. Just watch your tank. When your tank starts to look crowded then stop adding fish. There really is no “rule of thumb” for adding fish. This depends entirely on the mix of fish you choose. Good luck!

8. Luke wrote:
   1. July 2008 at 12:22 am :

   A fifteen should accommodate six pairs of Tera’s and the two or three Corie’s.A 20 gallon eight pairs of tetra’s two Corie’s and a Pleco would be nice.
   Good luck with your aquarium.