Currently unavailable. To mix up the perfect blend of Jack’s … Jack's Nutrients Calcium Nitrate Part B 15-0-0, 2.2lbs 4.6 out of 5 stars 39. It’s the shortened amount of each fertilizer in grams per gallon. It consists of Jack’s Nutrients Part A 5-12-26, Jack’s Nutrients Part B 15-0-0 and Epsom Salts. U can mess with these numbers a bit and there is twenty threads on here with tons of information. Calcium Nitrate 15.5-0-0 Fertilizer Bulk Pricing (5 POUNDS) 4.7 out of 5 stars 498. Jack’s 321 is our tried and true two-part fertilizer program. now in stock! Jack's Nutrients Tap 15-5-20, 2.2lbs 5 out of 5 stars 7 $30.86 $ 30. BUT where does that “321” come from, you ask? $29.97. Vendor: JR PETERS INC. Request Information. Share. Description. $13.89. Jack's is 3-2-1 3 grams Jack's 2 grams Cal nit 1 gram Epsom. This redesigned blend is built with purely soluble and available nutrients to allow the grower maximum flexibility. Only 4 left in stock - order soon. U should be using Jack's hydro though. It consists of Jack’s Nutrients Part A 5-12-26, Jack’s Nutrients Part B 15-0-0 and Epsom Salt.BUT where does that “321” come from, you ask? All you need is jacks “part a” the 5-12-26 formula, calcium nitrate & Epsom salts. Jacks Nutrients 5-12-26 Part A FeED 25LB Bag 79030. Not sure if … Using the 2 part system of Part A 5-12-26 and Part B 15.5-0-0 almost any nutrient combination can be made for all stages of a plants life, suitable and customizable for any crop type as well! 99. 2.4-cal nit & 1.2 Epsom salts.) Jacks Hydroponic 5-12-26 Part A Fertilizer 4.9 out of 5 stars 49 $65.99 $ 65. Mega Crop 2 Part is a 2 part nutrient system that is suitable for Hydroponics, Fertilizer Injectors and Soil. UM: BAG. Product Details; An improvement on the classic "Part A" formula for general vegetative growing. It’s the shortened amount of each fertilizer in grams per gallon. 86. Jack's Nutrients RO 12-4-16, 2.2lbs 5 out of 5 stars 5 $33.13 $ 33. We don't know when or if this item will be back in stock. But that's the basic rule of thumb. And you mix them in a 321 ratio (full strength being 3.6-jacks. Item # 33-51226. Image Unavailable. 13. Jack’s 321 is our tried and true two-part fertilizer program.