Hydrofarm GROW T JSCPB Coco Coir Mix Brick set of 3

Does this product contain fungicide?

Is this buffered or does it need rinsed to remove excess salt before use? I want to start seeds in it and add it to potting mix but I don't want salt.

What is the length and width of the individual fibers? How finely ground is it

How size are each of the bricks as far as weight goes?