Sex of my Juvenile Kribensis

Hi All!
I would be grateful for your help in sexing this juvenile that I purchased from LFS about three weeks ago. Got two, they were pretty skinny and colourless at the store, but have gained weight and look better.
I got two. Supposedly male and female. This one is chasing and traumatizing the smaller one which I do believe is a girl. I separated them for now.All photos except very last one is the same fish. The last one is of the female (I think).

 

That is definitely a male.
And the second is definitely a female. They will be breeding in a month or so.

 

Ok! Awesome! Thank you! They are still tiny. The male is a bit bigger (at 1 1/2 inches) and tormented the female to the point she jammed herself into the plants and wouldn’t come out. So I split them up for now. How long should I wait to put them both back in the big tank? The female was not eating, but since separated, has coloured up tons and gained weight. The male (now that I know—thank you again), is extremely confident and owns any tank he is in. He started to get the pink belly and wasn’t as skinny as when he came, so began to wonder if he might be a female too.
Thank you for the help!

 

Ok! Awesome! Thank you! They are still tiny. The male is a bit bigger (at 1 1/2 inches) and tormented the female to the point she jammed herself into the plants and wouldn’t come out. So I split them up for now. How long should I wait to put them both back in the big tank? The female was not eating, but since separated, has coloured up tons and gained weight. The male (now that I know—thank you again), is extremely confident and owns any tank he is in. He started to get the pink belly and wasn’t as skinny as when he came, so began to wonder if he might be a female too.
Thank you for the help!

Females will get a giant belly to the point of you thinking the have a deformity. I've never had a problem with any of mine being aggressive towards each other. I would put the less aggressive on back in the tank you want them both to be in. That way its "her tank". How many hides and caves do you have in your tank?

 

Females will get a giant belly to the point of you thinking the have a deformity. I've never had a problem with any of mine being aggressive towards each other. I would put the less aggressive on back in the tank you want them both to be in. That way its "her tank". How many hides and caves do you have in your tank?

Thank you! I will wait a bit then. There are three great spots in the big tank: one coconut shell, one pleco ceramic hide and a rock ledge area with anubias and Java ferns that they can excavate (sand substrate) on the other end, so they have a few areas if they choose. Is that enough? It’s a 20 gallon.

 

Thank you! I will wait a bit then. There are three great spots in the big tank: one coconut shell, one pleco ceramic hide and a rock ledge area with anubias and Java ferns that they can excavate (sand substrate) on the other end, so they have a few areas if they choose. Is that enough? It’s a 20 gallon.

I would put a couple more. Do you have any plecos in there?

 

I would put a couple more. Do you have any plecos in there?

No plecos. I bought it in prep for the Krib couple to give them a few choices. Only 4 platies, no bottom dwellers. A couple of female Endlers left over from my Endler breeding days.
I appreciate your time. Always wanted to try the Kribs, everything seemed so straightforward when I did my “homework”. Clearly, not so!

 

I would put a couple more. Do you have any plecos in there?

Hi Stripedbass! First, you were right in the money. Thank you! I now have about 50 juvenile Kribs, born October 17th, doing fantastic, getting some of their adult colour. Now they need homes. Lol