I am new to chickens and I am trying to do everything right. I want to know how many chickens I can have with the facilities I have built. I ordered 25 chicks from Stromberg's, I only lost one so far. They are 3 weeks old, 10 BOs, 9 RIRs and 5 SW. My coop is 8x8 and is 7' tall in the front and 5' tall in the rear. My run is 8' wide x 20' long and 6' tall. I am sure I will have to get rid of some of them, but I want to wait and see if I have any roosters in the bunch. On another note, I am wondering about ventilation. Right now, I have a storm door with a sliding window and screen. Other than that, the only ventilation is a small area where my light cord runs through that is about 6"x8". I open the glass during our warm days, but close it at night. Our night time temps are getting down in the mid 20s right now, so I hate to leave the screen open during the night. I plan on installing some windows with hardware cloth over them when it warms up. I have two brooder lamps, but I am only using one during the day, 40 degrees to 70 degrees, and two when the temps get down in the 20's.