To power grow fry you need to provide space and food - as big a space as possible Or constant drip flowing water. IMO, most important is constant nibbling on foods. You can achieve 10mm/month.
Keep in mind if you power grow body, fins will not develop to their maximum. I don't know why body and fins do not develop equally. Some locals believe that odd months develop more body while even months fins. Personally, doesn't make any difference.
I find best temperature is around 82.4 - 84.2C (82.4 - 84.2 F).
Three meals a day should be enough.
Some water change about 1g weekly for a 10g tank. Only siphon out water when fry is still too small. You could attach an airstone to your tube or place a fine mesh net on water surface and siphon inside of net. . . . . You need to be creative and use what ever works for you. Once fry is able to evade suction, then you could siphon out wastes.
Personally I don't change water during the first month or two, especially for bigger tubs. Keep in mind that mine are outside and heavily planted with lots of pest snails.