Usually when you buy saltwater from an
LFS they give you the specs of the water, slainity, etc. Did the distributor provide you with the specs of the water. Why yellow water i don't know - can't think of what would precipitate out of the distributers water that would turn water yellow except
DOC's (dissolved organic compounds) of some type.
First off, i would look for an LFS that has premixed saltwater (if you don't or can't make your own) and i would start doing water changes right away. I would measure all of your water values:
ammonia,
nitrite,
salinity, pH, KH,
GH, etc., if you havent't already. Then if these values are close to what the LFS has or your own, i would myself do a 25%
water change. If the values are significantly different, especially your salinity, pH, KH i would statrt with 10%. Either way, i would continue with water changes until you have essentially removed not just the yellow tinge, but brought the water paramenters into acceptable range (if they aren't). With activiated carbon there is no real concensus on when to change but i would recomend changing about three to four days minimum.
I am not sure i would use that distributor - maybe a one time incident - but
SW changes are expensive, and bad water is stressfull to you and the tank inhabitants obviuosly.
Hope this helps.