Tank Strife

[ptdecker]

I had a great 30 gallon tank with three Zebras, one Molly and an albino small catfish. Everybody got along fine; however, my wife and daughter wanted more color in the tank. So, we bought two pairs of fancy guppies and one beta. The zebras (I think) have killed the guppies by chewing their tail. The molly and beta were threating each other and this morning the beta's swim bladder is broken (he cannot float and must swim to get to the top). I expect him to die too. I was told that all the fish I selected were community fish and would get along. What gives? Help!

 

[Alien Anna]

I'm sorry you learned the hard way

Guppies and bettas are completely incompatible - the betta will mistake the guppies tails for the of other male bettas, and will therefore attack them on sight. Mollies are extremely dominant fish, as are bettas, which probably resulted in the fight to the death, although it could have been an accident. Basically, if you choose incompatible fish this sort of thing can happen. It's another good reason to always have a spare hospital tank, however.

Unfortunately, what you were told was a load of old cobblers, which is not unusual - on this forum we hear the most idiotic advice from fish shop people, some of which is fatal to the fish. For future reference, here are a few facts about your fish:

1. It is unusual for zebras (I presume you mean zebra danios, not zebra cichlids, or zebra plecs? ) to be vicious but they are schooling fish and should really be in groups of at least 6. They also need plenty of swimming space and good aeration and preferably a current to swim against. They can tolerate a wide variety of water but prefer neutral, slightly soft water.

2. Mollys are brackish water fish (that means they need salt in their water ideally) and like hard, alkaline water. Although not schooling fish they do like to be in family groups, preferably one male to 3 females. A male on his own may become bored and therefore destructive.

3. If the "small catfish" is an albino cory (fairly good bet, even though there are hundreds of different species of catfish) they require soft, acid water and being schooling fish should ideally not be kept in groups less than 6. They like plenty of plant cover and bogwood to hide in. They need good oxygenation as they cannot easily reach the surface for more oxygen and do not cope well with an un-cycled tank. They are intolerant to salt.

4. Guppies are livebearers like mollies and also like fairly hard, alkaline water although they are pretty tolerant of conditions. They also like current and tend to swim in the upper regions of the tank. They too are not schooling fish and like to be in 1 male, several female family groups. Males on their own may fight or even kill each other although this can be helped by plenty of cover and hiding places. Their frilly tails can look like lures to insectivorous fish, and can be mistaken for competition by bettas and other aggressive fish. However, guppies are most in danger from their own kind, in my experience. Guppies are good companions for mollies and platties in a "livebearer" tank.

5. Bettas like relatively shallow water and prefer relatively soft, acid water although they are pretty tolerant of water conditions. When stressed they are susceptible to various infections especially fin-rot (which might be partly caused by over-breeding). They are extremely territorial and will fight to the death any fish they view as competition, particularly guppies and other fish with trailing fins. They are not considered good community fish, although they can tolerate a community setting if you choose carefully. Generally this involves choosing companions for the betta, rather than the other way around.

I'm not sure what fish you have left, but if you'd like to post again I'm sure we'd all be glad to guide you a little better this time.

 

[Kossy]

Betta's also wont go together really with mollies unfortunately.