I assume your nominal 15 gallon tank is 24"x12"x12". It will actually hold a tiny bit less than 15 gallons filled to the brim. If you have 1 inch of gravel for plants to grow in and fill to within 1" of the top, the tank will hold 12.46 US Gallons.
Depends on the kind and size of the fish. You should also take in to consideration how large they will get at adulthood. A good rule of thumb to go by is 1 gallon of water for every 1 inch of fish. So for example: 3 2" fish should be in at least 6 gallons of water. To be safe I would put them in a 10 gallon aquarium.
For optimal plant growth, add 1-2 tablespoons of fish emulsion per gallon of water.
For optimal plant growth, it is recommended to add 1-2 tablespoons of fish fertilizer per gallon of water.
Well, the general rule for keeping fish is that you should have at least one gallon of water per inch of fish. So a 5" fish will need at least a 5 gallon tank.
the maximum depth fish can live is 400 meters under water
No fish should be kept in a bowl. They should be kept in at least 10 gallons of water but usually more depending on how many fish you have and how many you have. A good general rule is for every inches of fish you should have 1 gallon of water keeping in mind that they will grow.
A 1 gallon tank could have one betta fish, but you will need to be diligent about changing the water on a regular basis. The smallest tank that should be used, even for a betta, is a 2.5 gallon tank as it at least gives the fish swimming room.
You can buy spring or distilled water at Wal-mart for less than $1 a gallon.
You should only have 1 fish per gallon of water in a fish tank. I wouldn't put more than 2 or 3 Neon Tetras in a 4 gallon aquarium with 1 Betta.
Depends on the size of the fish, but no more than a total of 17 inches of fish. 1 inch of fish per gallon of water.
It's recommended to perform a partial water change of about 25% every 2-4 weeks in a 29-gallon fish tank. Additionally, you should clean the filter once a month and regularly remove any debris or waste from the tank to maintain water quality and a healthy environment for your fish.
Depth of 1.5-2 m