Howzit JLW, A while back Fiberglass Hi. sent me regular Lam resin instead of UV. I called them and told them to send me the UV catalyst premeasured for 5 gals since I had ordered 2 - 5 gals buckets. When it arrived I weighed the amounts and it was 2.2 oz for 5 gals. Just noticed your UV cat powder is green, mine was white so might be different brand which could mean different amounts. Aloha,Kokua