There are so very many to choose from that it is impossible to compare them all. I would advise you to go for an external power filter that has several types of media that can be cleaned at different times without damageing the Bacterial content of the media too much. I do have one warning though. Never ever use an "Undergravel Filter" they are likely to release deadly toxins into your tank if you ever have a power blackout and kill all your fish.
The recommended tank size for keeping a goldfish in a healthy environment is at least 20 gallons for the first fish and an additional 10 gallons for each additional fish. A 3-gallon tank is not suitable for a goldfish as it is too small to provide enough space and proper filtration for the fish to thrive.
A Betta fish generally needs a minimum of 2.5 gallons of water in its tank to thrive. It is important to provide adequate space, filtration, and water quality for the well-being of the Betta fish.
The BiOrb retailers recommend at least 24 hours, and I would say definitley no less time than this. I was advised at 3 days, and I have now had 3 fish in my BiOrb for 2 weeks with no water or filtration problems.
Depending on weather or not you have filtration will be the key to your answer. If you do not have filtration on a 1 gallon tank, a Betta will be the only acceptable fish to place in your tank. Although many people have given several different kinds of fish from goldfish to Molly's alive and happy without filtration, it is definitely not recommended. Also you will want to change your Betta's water on a regular basis with treated tap water or R/O water. If you do have filtration on your tank, here is the best answer. 2 inches of ADULT fish per gallon. So you do not want to have more than 2 inches of adult fish. One 2 inch goldfish would be all you should keep BUT 4 or 5 Neon Tetra's,or 3 or 4 Glowfish would equal about 2 inches. You cant just go by the length because some fish have larger bodies and thus creating more waste. Hope this helped you out !!
4 feet
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12 fishes
A goldfish does not need an airpump, it needs 3 stage filtration and good water movement from something such as a box filter and/or power heads. A goldfish, however, is not suited for a 5 gallon tank. 10 gallons per goldfish is the recommended minimum, as they grow very large and require more oxygen than almost any other fish. I would recommend something smaller such as rosy minnows, guppies, or if you get a heater, small tropical fish like tetras. ALL fish however, need filtration, not just an air pump.
All your fish will die. My buddy dumped a six pack in there and they were all dead in 3 hours...dont put beer in a fish tank
you have to start a 'cycle'....you can buy it (its actually called 'cycle') from the store and depending on your big your tank is...you can put the whole bottle in and it will start the right amount of bacteria your tank needs. Or you can get a few liters of tank water from a friend with an 'established' tank and dump it in. You will have to wait .....then start with a few gold fish.....you really need to talk to a pet store fish guy....there are so many varibles (size of tank, where you put the tank, your filtration system ect ect.) unless you have a bowl with a betta (fighting fish) it really is alot of work. I have a 100 Gallon tank with koi :) Good luck.
You should have it running for about 2-3 days before putting fish in your tank.
Either fish you get you'll only want approximately 3 fish. 1) because these fish are considering schooling fish and they are very unhappy with less than three. 2) More than 3-4 fish will crowd your fish tank- this will cause nitrate/nitrite problems and your tank will be dirty all the time.