SO MANY CHICKS DYING!!

[Geena]

What is the ambient temperature there throughout the day and night? That doesn't look as if it would be anywhere near warm enough for chicks that young. LED bulbs give off very little heat. And then they have a fan on them as well?

 

[Wyorp Rock]

I wasn't able to count how many there were but initially, there were 200 and then a lot of them started dying.

I agree, looks like an LED light bulb and if you have a fan going, they are too cool.

Turn off the fan and provide them with more heat.
I would suggest that you get some Corid (Amprolium) and add that to their water as well. I see some questionable poops.

Dosing for Liquid Corid is 2 tsp or Powdered Corid is 1 1/2 tsp per gallon of water given for 5-7 days as the only source of drinking water. Keep your water stations cleaned of poop.
Do not add any other supplements or vitamins to their water during the course of treatment.

Birds are too young for Marek's to be showing up. Get them more heat, make sure there's plenty of water and feed.

 

[BirdsBeesTrees]

"The brooder does have a sheet over the screen that's let down at night and lifted up during the day. Today the sheet was lifted up at 11am. That's when I noticed that so many had died."

They need fresh air, do not put a sheet over the brooder.

 

[BelovedBirds]

I'm really just repeating by this point but I agree with the others, during the hotter daytimes they may be okay, but at night they need heat, and LED isnt going to do it. Its also pretty important you have a thermometer so that you can keep an eye on these temps and ensure they are neither too cool nor too hot.
I also agree on a couple of questionable poops, cant hurt to try the corrid as @Wyorp Rock has suggested.

 

[Shugercube]

I’m sorry, am I reading correctly that you have 200 chicks in a 9x3 brooder? That sounds WAY overcrowded! Please, someone correct me if I’m wrong, but chicks should have at least 1/2 sqft each in the brooder, so you’d need at LEAST a 100 sqft brooder (10’x10’ minimum). 9x3 is only enough room for about 54 chicks, AND you said part of that brooder is also sectioned off for silkies, so there is even less space for the chicks? PLUS they grow very fast, that even that as bare minimum won’t be enough space for very long. Being overcrowded can certainly cause high stress levels and increases the likelihood of disease and death.

 

[BelovedBirds]

I’m sorry, am I reading correctly that you have 200 chicks in a 9x3 brooder? That sounds WAY overcrowded! Please, someone correct me if I’m wrong, but chicks should have at least 1/2 sqft each in the brooder, so you’d need at LEAST a 100 sqft brooder (10’x10’ minimum). 9x3 is only enough room for about 54 chicks, AND you said part of that brooder is also sectioned off for silkies, so there is even less space for the chicks? PLUS they grow very fast, that even that as bare minimum won’t be enough space for very long. Being overcrowded can certainly cause high stress levels and increases the likelihood of disease and death.

started off with 200, now less-
the photos don't look very crowded to me so now I'm curious how many passed away @alligatorr ?