My girls are 9-10 weeks old and the 20% starter I am using says it is for up to 9 weeks. I did some searching here and confirmed that it's too early for layer food, but I saw a couple posts about DIY grower/developer. Is it true that I can mix the leftover starter 50/50 with rolled oats to achieve the right protein balance for the grower period? If so, how long do I do that for until layer food and should I add anything else to the mix? I can buy organic developer locally but I still have ~20 lbs of starter left. I'd love to use up the rest of the starter rather than buy the 50 lb bag of grower, but only if it would be good for the girls. Thanks in advance.