Agreed about electrolytes. Honestly, I never like vitamins/electrolytes in the water unless the birds are weak - preferably use good clean water r Glenda's *organic* apple cider vinegar mixture.
We kind of need more info tho- is the food medicated and if so, with amprolium or something else? What are their droppings like - very specifically? What's the source of the straw?
You'll want to take a good hour when you first put the food and water in and see who's eating and drinking a good amount and who's not. It's so important with chicks.
Also agreed with Glenda's temp recommendations. I do this and then make sure there's room for the chicks to get away from it. But there's always a spot in there that is at least that high, for me, for two weeks. I find that a lot of chicks still like to go bask under that light for a minute or two. And then they should have room to get away. I like to see my chicks sleeping close but not heaped about 6-8 inches away from directly beneath my heat source. Closer and they may smother one another, further and I back the heat off unless they have plenty of room (like at least 2 feet) to get away from the light and aren't staying at the far end away from the heat.
Personally, I'm not a fan of straw bedding. It holds too much mildew, hides dropping consistency, doesn't dry up droppings well, etc.
As for the babies that are weak, I'd remove them to a separate brooder where they won't get bullied or pushed around by the vigorous other babies. That way you can monitor their eating and drinking better.
I wish you luck with these babies and will be watching to see how it goes.