Cimarron29414

Okay, I know too much about fish, but I'm going to bullet point because I don't have a huge amount of time. (Credentials: I started with a 10 gallon tank and went so far as to breeding soft corals in a national coral exchange program.)

Rule: 1 in. of fish per gallon of water. With substrate, you can have about 4 in. of fish in your tank. Personally, I'd accidentally break that tank and immediately go buy at least a 10 gallon. I have beer mugs bigger than your aquarium.

Rule: Goldfish have straight stomachs, so they digest very little of their food and produce alot of waste. This increases nitrates in the tank and causes algae for a poorly filtered aquarium. Poor lighting spectrum (cheap or aged lightbulbs) will further contribute to algae proliferation. Lightbulbs need to be replaced every six months. This also means you need to say 1 in. of goldfish per 2 gallons of water.

Rule: Goldfish are really good for priming a new aquarium with the bacteria necessary to have a healthy environment. The bacteria grows because it feeds on fish waste. The more food, the more bacteria to eat it. This is known as biological filtration. Usually, I would start a new tank with goldfish and then move to the other species.

Rule: Get a filtration system with a good biological filtration system. Penguin is widely available and is really cheap and good filter for this. It eliminates the need for that under-gravel filter and the air stone. Hence, you have more volume in the tank for accessories and...fish.

Rule: Add aquarium salt to your aquarium. It increases the health of your fish and reduces the risk of some fungii. I used to breed African Cichlids and had my Specific Gravity at something like 1.012. If I recall correctly, 1.000 is pure fresh water and 1.020 is considered the low end of a salt water aquarium, just to give you some perspective. Even your run-of-the-mill fresh water tetras will thrive in a little salt.

Rule: Whatever size tank you have, it will not be big enough in 2 months. You will be looking at 55 gallon ones within a year. Mark my words. Have fun.

EDITED:

I agree on live plants. They produce a lot more oxygen for the tank and allow you to fudge the inch/gallon rule a lot more. It also creates hiding place for smaller fish and allows for better co-habitation with otherwise incompatible fish. There is no down side to live plants, in my opinion. Please don't throw them in a lake or river when you are sick of them, though. Kill them in the trash.

__________________
Gives a man a halo, does mead.

"Here lies The_Jazz: Killed by an ambitious, sparkly, pink butterfly."