West System205-B Fast Hardener, Epoxy, Liquid, Epoxy Hardener, Clear

how much hardner do i need for 4.35 gallons?

I have used Envirotex Lite to coat tiles and it is crystal clear but SO long to cure. Question is if this is crystal clear? And how long to cure?

Do these containers come full ? appeared to have channellock marks on lid channel and there was hardener on inner lid. Missing 2 inches of product.

My set of resin and hardener came today, but the hardener is brownish/redish in color when I pump it out. Is that correct or should I return it?