I think it depends on what state you live in as far as legalities go. I think in my state it's 3 acres for the ffirst horse and 1 for each additional horse. So it would be 8 for 6. BUT, if you have a barn and each horse has a stall that it is assigned to then you don't have to have quite as many. But that is assuming you feed hay AND grain to each horse.
"Be a best friend, tell the truth, and overuse I love you
Go to work, do your best, don't outsmart your common sense
Never let your prayin knees get lazy
And love like crazy"