I think I got this one.
8000gms x .15% = 12gms chrome oxide (recipe)
You put in 8000 x .75% = 60 gms
You have 4x too much chrome oxide
So you need to make up 32000gms (4X8000gms) of the original glaze minus the chrome oxide.
Which with your original 8000gms = 40000 or 4 buckets of 10000gms . You need to buy 3 since you already have one
Check answer. You will have 40000gms x .15% chrome = 60 gms chrome oxide.
And you will have a lot of glaze.
Why can I do this so much easier than throwing a pot???