Athena Mix Kit makes it easy and accurate to mix a concentrated fertilizer mix. Just add a single pouch to the matching 1 gallon just, fill with water and shake until fully dissolved. Look for Athena 10 lb Pro Line box for refill pouches. 

Weighing powders is inaccurate and can lead to batches with different mineral compositions and ultimately plant deficiencies. It's always better to mix a concentrate first before measuring into a batch tank or reservoir