First time BHO run, doesnt seem right?

Me and my neighbor decided to make a small BHO run. We used a 1 1/2 " piece of PVC pipe with a hole dirlled in one end the size of the butanes tip, two un-bleached coffe filters, and made sure it was sealed. We ran 1 5.5oz can of butane through it, into a pyrex glass dish while it was inside a larger dish with hot water. My question is, while we used pretty decent bud (Very green, few seeds and stems, homegrown bud) our liquid coming out looked very clear and not yellow hardly at all. When it dried, we managed to scrape up about a .8 little ball of brown wax. It tasted pretty good, and got us both high, but I feel like we should have gotten more, and better results. We used close to an ounce of bud ( About 25 - 26 grams) and followed the instructions perfectly. While all the BHO I've seen online bubbles when they purge it on the stove, our liquid dried up and left almost nothing on the dish, and we had to scrape for ages to get what little we did. What did we do wrong? Thanks!