I have a beginners question regarding heating plates. I am trying to decide about heating source for my brooder, which I'm working on now for chicks arriving in early April. I am expecting 25 chicks. How can 50 chicks fit under a heating plate that is only 16" by 22" (the Brinsea 50, for example)? I can see how this would work for the first week or so (maybe), but, from what I've been reading on BYC, these chicks will need supplemental heat until they are about 10 weeks old (it doesn't get to 55 degree nights here until maybe mid-June). Wouldn't I just have to switch to heat lamps for 25 chicks as they grow, anyway?