Looking for a fish for my small aquarium

Question

I have a 4 gallon tank with air pump(its a biorb tank), Its been a year with a male and female betta as the tankmates. I just wanted an opinion if I can add one more fish to the tank. If yes, then what can I go for. The male and the female go along well and its been more than a year.

Answer 1

Rule of thumb is one fish per gallon. I'd leave it alone or maybe add a cory catfish. no more. Best of luck.

Answer 2

The fact your Betta's get along in such a small space is great.

No more tank mates for them...in such tight quarters, and since they are doing good together, it might upset the balance you currently have.  With Betta's the male usually shows aggression to other Male Betta's and specific other fish...as well as female Betta's(especially after breeding).  If you get a bigger tank, and place your Betta with other fish, make sure you stay away Gourami, Guppies, and colorful fish with long fins.  Use caution with fin nippers also...like Tiger Barbs, Black Skirt Tetra, and Angels...they are much faster than the Betta..and will attack his fins.

As far as the one inch/one gallon rule...and the one fish/one gallon rule...These are totally false.

EXamples of why... one inch/one gallon...if ya have a fish that is 10 inches long in a 10 Gallon tank...which by the rule is feasible, the he would have no turning room since the 10 Gallon tank is only 12 inches in width and height.  Also he would be laying horizonal with the tank at half the size of the tank and would have no swimming room.

For the one fish/one gallon rule...I have 1 fish that is 10 inches long in a 1 gallon tank...LOL!  Impossible to be compatable with life for too long.

Either way, there is a usually minimum tank requirement with different species and sometimes you can skirt this only if the filtration is more than required and the tank is not too small for the size of the fish...and they have some swimming room.

Best of Luck!

Answer 3

The rule of thumb is one gallon of water per INCH of fish.  Bettas are aggressive and your tank is small, so I wouldn't add anything.  I'd get another tank if I wanted more fish.

Which Calculation to Use?

As a general yardstick for normal situations, the one-inch rule works adequately and is very easy to calculate. If using it, always use net gallons of water, and take into account the adult size as well as the shape of the fish. If the aquarium is a non-standard size, the surface area rule will work better than the one-inch rule. In either case, always do your homework first, and err on the side of going under the limit rather than over.

Also do not fully stock the tank all at one time. No more than 25% of the total volume of fish should be introduced at one time. Fish wastes, which are toxic, are eliminated by colonies of beneficial bacteria. Those bacterial colonies need time to adjust to changes in the bio-load. By introducing fish a few at a time, the bacterial colonies have sufficient time to grow and take care of the toxins produced by the fish waste.