Kribensis breeding / aggressive female

Question
QUESTION: Hello Alex

My son is keen to breed kribensis.  We have a fully cycled AquaOne 620 tank
(about 23 gallons) with three caves.

Today we put one male on the tank with the female and she has not stopped
harassing the poor guy.  We went out for a few hours and when we came
home he was looking quite damaged.  I have confined him in the tank (he
swam into a cave and I stuck the net on the front) but I think I will remove
him
altogether to another tank and hope he survives.

I thought they'd pair off right away since they are the only male and female in
there.  But no.

Should I have three or four males to one female in the hopes she harasses
them all a little bit only?  Then remove the spare males when she chooses
one?  Or is she just a bit of a man-eater and a dud for breeding?

She has left the two ottos and the two albino catfish quite alone.  

It's a great pity I got my son this birthday treat the day before his birthday.  
Waking up to a dead fish tomorrow wont make for a great day!

: ((
ANSWER: In the wild,the female lays her eggs and a male comes along and fertilizes them,he then leaves so the female looks after them.But in a tank the male just cant leave the aquarium so he is stuck with a nasty girlfriend.What some people do is buy 2 females and 3 or 4 males,let them work it all out and the dominant couple will breed,so you remove the other fish.Once the male has fertilised the eggs remove him if you want to keep the fry,but i imagine your son wants to keep a pair of adult fish as pets,so i recommend choosing some other fish to breed,convict cichlids are easy to breed and can stay together in one tank with their babies as long as hiding places are available for the male just incase they fall out now and then,this happens to young fish that have not learnt how to fully care for their babies yet.
I hope this helps!!!

---------- FOLLOW-UP ----------

QUESTION: Thank you Alex!  
If we decide to go with Convict cichlids, would one male and female be sufficient
to get a pair...or are they choosy? Would the catfish and the ottos become lunch?

PS I moved the poor male krib, but he died in the night.  : (

Answer
sorry to hear about the crib :(
Yes,a male and a female are fine because they breed like rabbits anyway without needing to find a pair,you may even find a pair in the store with other convicts.
The convicts should be ok they would just chase the fish away from their babies.