Feedchart Usage Guide

All amounts per 3.79 liters (1 US gallon)

Conversion chart

2.5 ml = 0.5 teaspoon
5 ml = 1 teaspoon
3.785 l = 1 gallon

Recirculating Nutrient Solution Tips

Keep nutrient solution temperature below 75F (24 C)
Change nutrient solution every 7-10 days and top off with fresh water between nutrient changes
For best results maintain nutrient solution pH between 5.5-6.5
Keep nutrient solution aerated

Troubleshooting factors to consider

Arid, bright, hot environments cause plants to drink more than if they are grown where it’s humid, dim and cool. Thus gardeners should use less concentrated nutrient solutions when growing conditions are more intense in order to lessen the risk of overfeeding.
The pH (acidity or alkalinity) of a nutrient solution affects the availability of the elements contained within. Use GH pH adjusters to maintain nutrient pH between 5.5-6.5

Frequently asked questions

View all FAQs

Where can I go to learn more about feedcharts?

Our Feedchart Usage Guide explains how to interpret and use General Hydroponics® Pro Feedcharts. It is intended as a companion piece to General Hydroponics® Pro feedcharts for FloraPro®, FloraSeries®, and Maxi Series™.

Can GH nutrients be used in soil?

Absolutely! All of our nutrient blends contain the necessary elements for plant growth. Start with the formula ratios identified on the label for the specific plant or crop you are growing, and then adjust and experiment until you find the right formula for your specific need.

For further information, refer to our feedcharts.

Can you explain pH in a little more detail?

pH is a measure of the hydronium ion H3O+. It is based on a logarithmic scale from 0 to 14. “Pure” water has a pH of 7.0. If the pH is less than 7, the solution is acid. If the pH is greater than 7 it is alkaline. Because the scale is logarithmic and not linear, a pH of 6 indicates ten times more H protons than a pH of 7, and a pH of 5 indicates 10 times more protons than a pH of 6.

How does fresh air affect plant growth?

Ventilation is often overlooked as a problem. Plants absorb nutrients when the water molecules in the leaves respire (i.e. evaporate). Better ventilation aids a high transpiration rate, which translates into a greater rate of nutrient uptake. Remember that ventilation means changing the air, not just blowing it around the room (circulation).

How does pH level affect plant growth?

pH is important because it affects availability and absorption of several of the 16 atomic elements needed for plant growth. Maximum absorption of these elements is found at pH readings 5.5 to 6.5. When pH falls below this range many of the macro elements (N, P, K) have less availability, and absorption of the micro nutrients can reach toxic levels.

How important is water quality in hydroponics?

Water containing too much calcium and magnesium (called “total Hardness”) may create serious problems. Contact your municipal water supplier who can provide you with an analysis of your water supply. If you are using well water, many laboratories can provide you with an analysis if you send them a sample. If the dissolved salts in your water supply measure 200 ppm or more, we strongly recommend that you obtain a water analysis to determine calcium content. Excessive calcium is the main factor in determining if your water is hard. If an analysis of your water supply reveals that the Calcium content of your water supply is greater than 70 ppm (mg/liter) you should use Hardwater FloraMicro. Hardwater FloraMicro provides rapidly growing plants with a combination of chelated micro nutrients uniquely formulated for hardwater conditions. Other options are to collect rainwater, install a reverse osmosis filtration system, or use purified water. Do not use mineral or “spring” water, which can unbalance the nutrient solution, or even be toxic to plants.