Post
by Diana » Wed Jul 11, 2007 12:53 am
Here are 2 guidelines for maximum stocking levels, some basic background information, and an analogy.
Fact: A fish that is twice as long as another fish (same shape) is also twice as wide and twice as tall. That is 8 times the mass, and therefore 8 times the waste, 8 times the oxygen requirement, 8 times the carbon dioxide production.
Lets take 2 fish, one is 1" long, and the other is 2" long.
Fish #1 is 1" long, 1/4" tall, 1/4" wide, = .0625 cubic inches.
Fish #2 is 2" long, 1/2" tall, 1/2" wide, = .5 cubic inches.
Fish #2 requires 8 times the oxygen, and generates 8 times the waste as fish #1.
Fish #3 is 3" long, 3/4" tall, 3/4" wide, = 1.6875 cubic inches. This fish is 27 times the size of the 1" fish.
(An Angel fish that is 3-1/2" long is also close to 3" tall, but maybe only 1/2" wide = 5-1/4 cubic inches, 84 times the mass of the 1" fish.
Please measure the inside of your tank. I have a 15 gallon tank, and it really only holds 12 gallons of water, and this is without rocks, sand and so on taking up space. (My tank is: 23-1/2" x 11-1/2" x 10" = 11.73 gallons)
OK, now for some "fish stocking guidelines":
1) For fish under 2" long, 1 gallon of water per 1" of fish. You have 17" of fish, even if the Angels could be included (at 3-1/2" they are NOT 'fish under 2" long') If you double the water for the angels (see math above, they really need a LOT more than double the water) You need: 24 gallons.
This is just barely enough to keep oxygen in the water, and keep the waste diluted between water changes. A bigger tank would help by diluting the waste better between water changes, holding more oxygen and so on.
This does not address the social issues of these fish. A mated pair of Angels could very will kill all the other fish in this tank because the other fish are invading the Angels' territory. Angels eat small fish; the 1/2" Neon is safe, only as long as the Angels are well fed, which leads to further waste control issues. Some Loaches are pretty easy going, small critters that would do OK in this size tank (Kuhlies come to mind) but other Loaches are pretty aggressive, and need their space. Most Loaches are pretty particular about waste building up, and will not tolerate nitrates over 20 ppm. Most Loaches come from fast moving, somewhat shallow streams and rivers. They thrive in fast moving, well oxygenated water. Angels are native to slow moving flooded land in the amazon basin. They thrive in warm, acidic water, without much water movement.
Here is another method of determining stocking level based on oxygen entering the water and CO2 leaving the water. This is not based on wastes such as the Nitrogen cycle.
2) Measure the surface area of your tank. Here is the weird part: Measure 1 way in feet, the other way in inches. Multiply. This is how much fish-inches (of fish under 2") the tank can provide oxygen for. Using my tank: 23.5 is so close to 2', I will call it that. 11.5 x 2= 23" of fish. If your tank is the same as mine, you are safe for the moment as far as supplying oxygen and getting rid of CO2. Pray your water circulation (Filter, bubbler, powerhead) never quit.
Like the other method, this says NOTHING about the social issues of the fish, and really does not hold for fish over 2".
Here is another thought: Put a cat and a dog who get along reasonably in a large room. Will there be issues? Maybe, but the cat can get away from the dog on those occasions. Put the same cat and dog in a bathroom. What will happen when the cat needs a break from the dog? (Or the other way around) This is the current set up for your tank: That bathroom is WAY too small for even a cat and dog that usually get along pretty well.
38 tanks, 2 ponds over 4000 liters of water to keep clean and fresh.
Happy fish keeping!