Jack's Professional 21-5-20 All Purpose LX Fertilizer, 25 lb

Jack's Professional 21-5-20 All Purpose LX Feed

Hard, alkaline irrigation water slowly drags root-zone pH upward, and iron and manganese drop out of reach as it climbs. This JR Peters formula is built to push back. It carries 407 lb of potential acidity per ton, measured as calcium carbonate equivalent, so each feeding offsets some of the bicarbonate in the water. The guaranteed analysis is 21% nitrogen, 5% phosphate and 20% potash. Of that nitrogen, 7.92% is ammoniacal and 13.08% is nitrate, which is where the acidifying effect comes from. Phosphorus sits low on purpose, and that keeps stems compact rather than stretched. Micronutrients come in at 0.105% iron, 0.0525% manganese, 0.0525% zinc and 0.0105% copper, all chelated with EDTA. Boron, molybdenum and 0.15% magnesium round out the package. Inputs are ammonium nitrate, monopotassium phosphate, potassium nitrate and magnesium sulfate, plus the micronutrient sources. The powder dissolves up to 4.5 lb per gallon of stock, and warm water speeds it along. At 200 ppm nitrogen, one 25 lb bag yields roughly 3,100 gallons of finished feed.

Running This Water Soluble Fertilizer Through an Injector

The label table makes setup quick. For 100 ppm nitrogen on a 1:100 injector, dissolve 6.43 oz per gallon of stock, and expect an EC near 0.65 mS. Double the stock strength for the top label rate, which many growers hold through active vegetative growth. On a 1:15 proportioner the same targets need far less powder per gallon, so read the right column before mixing. Check the injector setting before every run, since a slipped dial changes everything downstream. Keep the stock tank covered to cut light and debris, both of which feed algae in the concentrate. Calcium nitrate belongs in a separate stock tank, because concentrated calcium meets sulfate and phosphate badly in one barrel. Watch substrate pH over the first weeks, as this feed lowers it steadily on water that started near neutral. On soft or RO water it can acidify too far, so a basic formula usually suits that situation better. It fits bedding plants, potted crops and plugs at light rates, as well as soilless mixes and greenhouse hydroponics. Molybdenum on the label carries a caution for forage crops grazed by ruminant animals.

Key Features

• 21-5-20 With Chelated Micros: Complete feed with EDTA-chelated iron, manganese, zinc and copper that stay available.
• 407 lb Potential Acidity: Offsets bicarbonate in alkaline water and steadies root-zone pH over time.
• Low Phosphorus: Keeps growth compact and toned instead of stretched.
• Injector Ready: Label table covers 1:15, 1:100 and 1:200 injectors at 50, 100 and 200 ppm N.
• High Solubility: Dissolves up to 4.5 lb per gallon for concentrated stock solutions.
• 25 lb Bag: Makes roughly 3,100 gallons of finished feed at 200 ppm nitrogen.

Technical Specifications