About half the time when I water the pumpkin plants while they are still in the hoop house I only use compost tea. I figure if I can give the plants some additional beneficial bacteria and fungi while the roots are still small then why not give them something more than just water. Compost tea gives very little NPK but should be giving the soil the biology that helps break down the nutrients in the soil to a form that the pumpkin plants can more readily use which should help the growth of the plant and overwhelm the soil with good bacteria that will keep the bad biology in check.
If you haven't started already, it isn't to late to get some giant pumpkin seeds for this season. Competition quality seeds started at this point could get you a pumpkin over 300 pounds by the end of the season and it is a lot of fun to do as a family (or to just show up the neighbors come Halloween time).