Preparing Low-Cost A+B Hydroponic Nutrients from Raw Salts
Buying pre-mixed, brand-name "Flora Series" or other liquid A+B nutrient solutions is incredibly convenient. But as your hydroponic garden or commercial greenhouse grows, paying for liquid water becomes an expensive habit. By mastering the art of DIY A+B stock solutions from generic raw salts, you can cut your nutrient costs by up to 80% while gaining complete control over your plant's diet.
Quick Summary
- Why A+B? To prevent concentrated Calcium (from Calcium Nitrate) from reacting with Sulfates and Phosphates to form un-dissolvable gypsum.
- What you need: Basic raw salts (Calcium Nitrate, Epsom Salt, MKP, Potassium Sulfate, Chelated Micros), a digital scale, and distilled water.
- The Tool: Use the built-in Stock Solution Toggle in our calculator to automatically separate your theoretical recipe into safe A and B buckets.
The Chemistry: Why We Need an "A" and a "B" Bottle
The most critical rule in hydroponic nutrient preparation is simple: Never mix concentrated Calcium and Sulfates/Phosphates in the same bottle.
If you take high amounts of Calcium Nitrate (Ca(NO₃)₂) and mix it with Magnesium Sulfate (Epsom Salt) in a small volume of water, a chemical reaction occurs almost instantly. They precipitate out and form Calcium Sulfate (Gypsum). This white sludge sinks to the bottom of the bottle and becomes totally unavailable to your plants.
By splitting the nutrients into highly concentrated Part A (containing Calcium and Iron) and Part B (containing the Phosphorus and Sulfur), they stay fully dissolved. You only ever mix them together when diluting them into your final, high-volume reservoir tank.
How to Use the Stock Solution Calculator
Calculating the exact gram weights for a highly concentrated A+B mix used to require tedious spreadsheets. HydroNutrientCalc automates this completely. Follow these steps to design your own commercial-grade liquid fertilizer:
1Activate Stock Mode
Navigate to the Calculator page. In the Settings panel, check the "A+B Stock Solution" box.
2Set Volume & Concentration Factor
Decide how much liquid concentrate you want to make (e.g., 1 Liter bottleneck volume). Next, set your Concentration Factor (e.g., 100x). This means 1 Liter of your concentrate will treat exactly 100 Liters of fresh water at the dosing rate of 10mL/L.
3Automated Chemical Separation
Hit "Calculate". Our Non-Negative Least Squares (NNLS) algorithm determines the precise gram weights of your raw salts. More importantly, the Results Table automatically analyzes the chemistry and drops the salts into two safe lists:
- 🧪 Part A: Calcium Ammonium Nitrate, Iron Chelates, Potassium Nitrate
- 🧪 Part B: Magnesium Sulfate, Monopotassium Phosphate, Potassium Sulfate
Reading the Stock Analysis (% W/V)
When you enable Stock Mode, you'll see a special Stock Analysis (% W/V) pane below your results. If you've ever looked at the back of a commercial fertilizer bottle, you've seen numbers like "5-0-1" or "Total Nitrogen: 5%".
This pane converts your newly calculated DIY recipe into exactly that format: Weight per Volume percentage (grams of element per 100mL of stock solution). It allows you to directly verify and compare your DIY mix against expensive store-bought brands!