Even girls can fight so weight is so important and if a male is entered girls can fight too.
At young ages u can get the girl to young pregnant and this can cause health issues or death. They need to be 35grams before breeding.
I would sex them first if u can take a good macro shot of the area for pores I can tell u if it’s male or female.
Either way if u ever put cresties together watch them well and give them plenty of plants to hide in.
They are arboreal so I assume the 20gl is on end to give more height than length?
Would love to see pics of the babies!