I just finished my outdoor brooder and, while designing it, I thought it would be sufficient to keep them warm. I have the Brinsea, a MHP and a 75w bulb. I got 17 chicks today and they seem to be doing well but it is supposed to get down to 30 tonight and 28 tomorrow night (but 60's during the day). Should I bring the chicks in tonight or do you think the brooder will be enough? These are 2 day old chicks so no feathers yet
I think you can do away with the heat lamp and the brinsea. They will most likely all choose to congregate under one heat source. I might put the heat source closer to the food for the first couple of days to be sure they don't get lost. I've had chicks make the trek to the water/feed, and then start huddling behind the water in a corner b/c they had a lapse in memory of where the MHP is. I think that for the first week, I'd give them a tighter enclosure, you could even do so with a couple of hay bales, or some cardboard. This will help hold in a bit of heat and prevent drafts.
What an interesting experiment you have set up there!! Will be cool to see which heat source they choose over the next few days. Not sure the 75W will be enough, measuring the temp on the ground under the lamp would be a good idea. You might have to 'show' them the heat plates by holding them under there until they 'feel the heat'. As long as that area is protected from any drafts they should be fine at that temp. Go by their behavior as to if they are too cold or not. Here's my notes on chick heat, hope something in there might help: They need to be pretty warm(~85-90F on the brooder floor right under the lamp and 10-20 degrees cooler at the other end of brooder) for the first day or two, especially if they have been shipped, until they get to eating, drinking and moving around well. But after that it's best to keep them as cool as possible for optimal feather growth and quicker acclimation to outside temps. A lot of chick illnesses are attributed to too warm of a brooder. I do think it's a good idea to use a thermometer on the floor of the brooder to check the temps, especially when new at brooding, later I still use it but more out of curiosity than need. The best indicator of heat levels is to watch their behavior: If they are huddled/piled up right under the lamp and cheeping very loudly, they are too cold. If they are spread out on the absolute edges of the brooder as far from the lamp as possible, panting and/or cheeping very loudly, they are too hot. If they sleep around the edge of the lamp calmly just next to each other and spend time running all around the brooder they are juuuust right! The lamp is best at one end of the brooder with food/water at the other cooler end of the brooder, so they can get away from the heat or be under it as needed. Wattage of 'heat' bulb depends on size of brooder and ambient temperature of room brooder is in. Regular incandescent bulbs can be used, you might not need a 'heat bulb'. You can get red colored incandescent bulbs at a reptile supply source. A dimmer extension cord is an excellent way to adjust the output of the bulb to change the heat without changing the height of the lamp. Or you could go with a heat plate, commercially made or DIY: https://www.backyardchickens.com/a/pseudo-brooder-heater-plate
I would cut out two of the heat sources, they seem to prefer your heat lamp (from the photos). Too many choices for baby chicks to make. I also think the brooder is way too large for them at this time. I'd put up partitions or something to make it smaller, and make is easier to keep the heat in. When they start outgrowing the area, remove the partitions. PS make sure your heat lamp is attached/held in two different ways - as a safeguard against it falling.
