Q&A for How to Know How Many Fish You Can Place in a Fish Tank

Most choose to keep them separately as they require different conditions than most other aquatic animals.

Try quick ich X, it is a medicinal solution with a small amount of salt that is harmless to the fish, and should kill the parasite.

One harley needs 5 liters so if you want to keep them you can only get 2 harleys although they are 5 cm.

The general rule of thumb is 1" of fish per 4 liters, so you could have around five 3" fish, or four 4" fish.

I would not put fish that will be consumed and fish for decoration in the same tank. The tank water is not safe for human consumption.

Yes, it provides oxygen for the goldfish.

None. A one-gallon tank is too small for any fish. Guppies need at least 15 gallons.

It really depends on the fish species. If you have 20 chili rasboras, that won’t be a problem, because they only grow to 0.5 inch in length. If you have 20 mollies, 20 goldfish, for example, then you would definitely be overcrowded. There are not many types of fish that you can have 20 of in a 15-gallon tank.

A 120-gallon tank is too small for a 10-foot fish. The 1 inch of fish per gallon of water “rule” is inaccurate, contrary to popular belief. A 10-foot fish is going to need at least 10,000 gallons of water or even more, depending on the species.

You probably don't want to have more than 4 fish in that tank. If you are thinking of getting shoaling fish, I would recommend neon tetras; they are the hardiest tropical fish and very pretty. However, you should get a minimum of two tetras, as one will be lonely.

You could probably get 10 to 15 more fish in that tank; however, it could risk the tank's water quality and overall health. If you introduced them separately (3 - 5 at a time), then you should be able to do it. You would obviously have to change the water more regularly. Maybe you could breed your guppies; that is always a delight!

It is a bit crowded, but if they are happy, then that is fine. You may need to do more regular water changes. Consider purchasing Stress Coat so that they don't get stressed or start to show signs of aggression.

3 or 4, maybe 5 at most.

No! First of all, putting those fish in any tank is a recipe for disaster. Bettas will attack the guppies since they look similar but smaller. Also, your tank is the bare minimum for the community tank you would like. Try a different combination of fish or have one betta and a snail on your 16-liter tank.

Vacuum the substrate at least every two weeks to remove the fish waste.

Tetras need to be kept in schools of 5+. Small plecos (sucker fish) grow to be about six inches long. Guppies need at least 19 liters. All fish will severely overstock your tank. You should not house any fish in a tank under 9.5 liters, and the only fish you can house in 9.5 liters would be a betta and maybe some snails.

It depends on the fish. Aqadvisor is a good website that can help with stocking.

It depends on the type of tetras. If they're small, like neon tetras, you can add 7 neon tetras and 7 guppies.

You can keep two female bettas in your tank. Since bettas are very territorial, every female betta should have 37 liters.

To clean your fish tank, consider the size. Smaller tanks are easier to clean. Invest in a gravel vacuum. Use the gravel vacuum to siphon the gravel and remove around 50% of the water from your aquarium. Then, replace the water with dechlorinated tap water. Be sure to add water conditioner to dechlorinate the water, which will remove any heavy metals or chlorine. Unplug all equipment while you clean. For tanks under 2.5 gallons, remove the fish and put it in a cup of water from the tank. Then, dump all of the water out of the tank and clean the gravel. Then replace it with dechlorinated tap water, replace the decorations, and put the fish back in.

Go by the 1 inch of fish per gallon of water rule. Just remember to subtract out the space that is being used by plants, decorations and substrate.

You can only have one goldfish in that tank. Two would need 151 liters. It seems like a lot of space, but the fish will be much happier.

You can only have one goldfish in that tank. They need a lot of space, since they grow to be surprisingly big.

No, two goldfish would need 151 liters, or 40 gallons. I know it seems like a lot, but they'll be much happier. Goldfish grow to a surprising size.

There are a lot of factors that you should consider, from the size of your filter to the size and types of cichlids and the amount of food you will be feeding in a day .But for a normal size juvenile African cichlid, it would be around 8 to 12 in your tank. And for a full-grown African ciclhlid it would be around 6 to 8.