i think that would be fine. Adding 3-4 more females would be even better - that way if the male does get the idea into to head that he wants to breed or fight, any aggression that does result will be spread out to a very manageable level, rather than put on one single female.
I kept a pair in a 55 gal "planted " and raise their juvis until they were old enought to sell. Dad and Mom never bothered anyone but the kids started to get a bit unruly not long before they were sold at 6 months old.
Thanks for the help .It's just that I've had these fish for quite a while and thought that now that the 125 is planted it might be ok for them with the other community fish. I put the female in today and it looks like there is plenty of room for both.
I guess I might keep my eyes open for a couple more females.
I had betta's in a 27 gallon tank. I think there were about 4 females to one male, it was just enough to give the ladies a bit of a break. Lots of plants help too. With 125 gallons, why not get half a dozen females? Then it would be the randy male getting worn out.
I was going to say that the female is the one to worry about with the aggression but I see you and someone else have already had that experience. I was told to find a "brother/sister" pair or a pair that have already mated if you want to put them together otherwise the female will kill the male.