That doesn’t look too bad. They are avoiding the heated area but they are not lined up against the wall as far as they can get away from the heat. They’ve found a comfortable spot at least at that temperature. If that room heats up and cools off that could change but at least you are in the ballpark. How much does the temperature swing in that room?
Your goal is not to have a variety of heat intensities along the brooder, your goal is to have one area warm enough at the coldest temperatures and one area cool enough at the warmest temperatures. If you had the heating pad cave you’d have a warm spot in the cave and the area outside of the cave would cool off. With a heat lamp that tank is big enough you can heat one end and the rest will cool off if you have good ventilation up high. If your room temperature were constant day and night it’s possible to set up a heat source so the temperatures aren’t bad even with smaller tanks, but I’m really glad to see that larger tank, especially since your temperatures fluctuate some. Don’t worry about the temperatures in the tank at various points along the tank, just look at one end being warm enough and the other cool enough. They are really good at self-regulating if they have that option.
I personally don’t trust those heat lamp clamps at all, I consider them an accident waiting to happen, especially when those chicks start jumping and flying. I toss the clamp so I’m not even tempted to use it and hold mine up with wire so it cannot fall.
I know of three different ways to adjust the temperature on the heat lamps. As others mentioned, change the wattage. Dad never used a “heat lamp” bulb, he used a 60 watt white incandescent bulb but 60 watts was all he needed. I have a lot of trouble finding anything other than a 250 watt red heat lamp bulb, but a couple of years back I found a hardware store with 75 and 125 watt red bulbs and stocked up.
You can adjust the temperature by repositioning the bulb. Raise it to lower temperature, lower it to increase the temperature. Not knowing the temperatures in that room, I could see you putting the heat lamp on top with only part of the heat going into the tank, the rest of the heat going outside.
Some people put dimmers on those lamps so they can heat it up or cool it off by turning a dial. So that’s the three ways.
Your best guide to how you are doing is to watch the chicks. If they are huddling under the heat they are too cold. They will probably be giving a really plaintive peeping sound too. It’s different to their normal peeping and so sorrowful you know something is wrong when you hear it. If they are as far from the heat as they can get, lined up against the far wall, it’s too hot. They are usually lethargic and panting too. If they are in between they are doing OK.
They normally sleep in a group at night, in a comfortable area but often fairly close to the heat source. Then sleeping in a group does not mean they are cold, they just like the company.
Those look really young. Usually mine stick pretty close to the heat the first few days but it usually doesn’t take them long before they start moving around quite a bit when they are awake. It’s the same way with a broody hen, they seem to spend a lot of time under the broody the first few days but before long they are roaming all over.
