Aggressive Male Guppies - Help Me!

So I have a five gallon tank with three male Cobra Guppies. One of them is so aggressive the fish its bullying tail is three quarters of the way gone! I need help on why this is happening and how to fix this!

 

Please help

 

They could possibly be stressed from being in a too small tank... How long have you had them??

 

they've established a hierarchy and he's the alpha. 5 gallons might be too small for them. can we get a pic of the tank? is there enough stuff for them to hide in?

if you're worried then take the bully guppy out and put him back in later once things have settled down.

 

they've established a hierarchy and he's the alpha. 5 gallons might be too small for them. can we get a pic of the tank? is there enough stuff for them to hide in?

if you're worried then take the bully guppy out and put him back in later once things have settled down.

I agree. I would also rearrange some of the things in the tank and give the little ones time to get used to it before putting the bully back in. He will then be the new guy on the block and hopefully won't go back to bullying.

 

Other then increasing the size of the tank and getting a larger group to diffuse aggression, preferably with a one male to two female ratio, then increasing the amount of hiding spots and re arranging the tank will disrupt the hierarchy they have formed and give those lower in the food chain more places to hide and chill out.

How long has this been happening? It may be possible that once he is happy hes the boss the fighting will quiet down but its also possible he might just kill the others...

 

Some people have had success before at giving their aggressive guppy a "time out"--ie removing him to another container to be on his own. 5 gallons is really too small for guppies, so if you can upgrade them to at least a 10 gallon, they'll be happier and able to avoid each other better.

 

A 5 gallon is definitely small for Guppies. but do you think that they might also be stressed out by the absent of females in the tank?v

 

A 5 gallon is definitely small for Guppies. but do you think that they might also be stressed out by the absent of females in the tank?v

My fancy guppy time was a long time ago, but (after a settling in period) a group of males is perfectly doable--in fact, it's how most breeders have their fish. Adding females to the current setup would be a huge mistake, and if the OP is able to set up something larger and wanted to give that a try, they would do best with a 2 female: 1 male ratio, so they would need to get 6 females...which would reproduce and stress the new setup pretty quickly unless they were limited on food and decided to, err, keep their fry's population in check themselves.

Right now I have a group of somewhere around 30 male endler/guppy hybrids -- they're in a 37g with lots of plants and hiding spaces. I'm worried about one of them--he seems to be harassed constantly, but his body shape is very reminiscent of a female because of a birth defect. But he still has places to hide. Endler aren't as persistent as guppy males, but the key is having space, and having the right sized group...and having a backup plan. I think to the key to this is probably getting even a slightly larger tank, creating more escape areas, and increasing the numbers to disperse aggression. I would try that before getting females.