Bronze, ****. Leg problems with them are very common, they are bred to grow fast and sometimes the bones can't keep up.
You need to be feeding a high protein diet. You also can add water soluble vitamins and electrolytes to help. Its not a cure though. There isn't much can be done that is truly...
That is strange. I would try to drain it like you said.
If you can post pics, that would be good.
I've dealt with tons of chick related problems, but this is new to me. I'm really curious to see what comes out(color/thickness)