You'll want to wait until the females are at least 45 grams. 50 to 55 grams is better for breeding. Breeding them when they're smaller can hurt the female.
It's best to introduce the male to the female tank when you want to breed. The male can be territorial and might (or might not) hurt the female introduced in his domain. The girls are usually less dominant and will allow the male in their cage (unless she's a "HOT" female). A hot female is a female that was incubated at high temperatures and still came out female. they typically are more agressive, like a male, than a female that is incubated at 80-84 deg.
Hope this helps.
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JJay
3.4.1 Leos
(& 5 eggs cooking)
0.1 Map turtle