Lost wax casting

Hello,

I am new to lost wax casting and had an unsuccessful first casting. Maybe someone could help me out with identifying my errors.
I thought I studied enough, watched way too many youtube tutorials and prepared everything into detail but it still ended with non and partial fills.

I built a little wax tree with wax injected earrings, charm and hand carved rings, covered the tree with Goldstar OMEGA+ investment which i mixed with deionised water 40:100, vacuumed and then after 2 hours burnt them out in a 3.15" x 4" perforated flask, in a paragon E12 kiln for 12 hours (started at 300F - 400F - 700F - 1350F - 1130F Casting temp i held for more than 2 hours)

I used a KAYA cast for vacuum chamber casting, melted sterling silver until 1850F in an electric furnace and poured it in my mold, while it was in the vacuum chamber with full vacuum pressure on. After 5 min I quenched my flask and unfortunately just one charm made it completely (but also with some rough surface on the back). the bear charm was on the very top of the tree and the heaviest model. the top pair of earrings just filled half and the lower placed earrings stopped right at the sprues, same for the basic rings at the bottom of the wax tree. Now I figured as they were the smaller pieces they should have gone on top?

see attached pictures of the final tree and also the wax tree, and separate earrings to see the sprues better.

My guess would be that my sprues are too skinny and in the wrong placement? but they were like 3 mm which I though would be fine, also for the lower earrings I had 4 sprues attached to the inside of the earring to ensure the metal reaches the whole model. maybe too many or too complicated. They way I built up the wax tree must be wrong because I thought temperatures of flask and metal were fine.

Thanks for your help, really appreciate it!
Raffaela

Attachment 13011 Attachment 13012 Attachment 13013 Attachment 13010