Peters Professional Acid Special 21-7-7

5 out of 5 stars 2 Reviews | 2 Q&A

Peters Professional Acid Special 21-7-7

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Average Rating

5 out of 5 stars Rating: 5

2 Reviews | 2 Q&A

Product Overview

The Peters Professional Acid Special 21-7-7 (E99330) is a water soluble fertilizer that helps in producing healthy and acid loving crops. It has a formula with high potential acidity that lowers pH levels or offsets high water alkalinity in growing media. This fertilizer is the excellent choice for water type 3 and 4. It also contains a great range of micronutrients that's essential to promote greening.

Features and Specs

Active Ingredient Total Nitrogen - 21% Available Phosphate - 7% Soluble Potash - 7% Magnesium - 0.6%, Sulfur - 13.0%, Boron - 0.0262%, Copper - 0.0262%, Iron - 0.15%, Manganese - 0.05%, Molybdenum - 0.01%, Zinc - 0.05%
For use in Acid Loving Crops
Application 1 tsp per 1 gallon of water (1 tbsp per 2 gallons of water)
* Can be tank mixed for watering cans and spray tanks except injectors
* See label for complete application instructions
Color Blue
Material / Construction Ammonium Phosphate, Ammonium Sulfate, Urea, Potassium Sulfate, Magnesium Sulfate, Boric Acid, Copper EDTA, Iron EDTA, Manganese EDTA, Ammonium Molybdate, Zinc EDT
Special Features Water Soluble Fertilizer
Shipping Weight 25.26 lbs
Manufacturer Everris Na Inc. (Mfg. Number: E99330)
UPC 848264006792


Produce healthy acid-loving crops with this formula’s high potential acidity that offsets high water alkalinity or lowers pH levels in growing media.

  • C (Customizing) component can be used with a variety of B (Base) formulations
  • Excellent choice for Water Types 3 and 4
  • Contains a full range of essential micronutrients plus extra iron to promote greening

Product Properties:

Potential Acidity .......................... 1518 lbs calcium carbonate equivalent per ton

Conductivity of 100 ppm N ......... 0.52 mmhos/cm

Maximum Solubility ..................... 4 lbs/gallon

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  • 5 of 5 Stars

    Good response

    By Charles on 06/11/2016

    We have used Acid Special 21-7-7 for many years on blueberries in pots in the greenhouse with excellent response It gives a rapid response before a dry, slow release becomes available. Order and shipping were handled well and price was competitive. CMM, North Carolina

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    6 of 7 people found this review helpful

  • 5 of 5 Stars

    The Blueberry Person

    By Norm on 09/15/2022

    This fertilizer is excellent for blueberries. When used every 10 days during the growing season, it is a great stimulant of new plant growth, which increases fruit yield the following year.

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    2 of 2 people found this review helpful

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Questions & Answers

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Is there any way to calculate N/gal at a given concentration of Peters Professional Acid Special 21-7-7?

The product label for

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3 of 5 people found this answer helpful

trying to kill bandboo from growing back

Peters Professional Acid Special 21-7-7

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Peters Professional Acid Special 21-7-7 5 out of 5 stars Rating: 5 (2 Reviews / 2 Q&A)

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