General Hydroponics Feeding Schedule

About General Hydroponics

General Hydroponics is the line most people meet first, and there is a reason it has lasted: the three-part Flora series is about as forgiving as hydroponic nutrition gets. Grow, Micro and Bloom in different ratios cover a whole cycle, the bottles are cheap enough to experiment with, and the schedule is printed on every chart in the industry because so many other programs were built to imitate it.

It is also a genuinely broad catalogue — pH Up and Down, CALiMAGic, RapidStart, Armor Si, the FloraNova and MaxiGro/MaxiBloom one-parts, and the propagation hardware. If you want one brand that can feed a windowsill and a flood table with the same shelf, this is it.

Flora Series 3-Part weekly feed chart

These are General Hydroponics' own published figures, set out so you can read them on your phone in the grow room instead of pinching around a PDF. Three feed strengths cover the same 13-week cycle — four weeks of growth and nine of bloom. Pick your strength from the guide underneath the tables, not by guessing.

Aggressive feed

Aggressive — All amounts per 3.79 liters (1 U.S. gallon)
Feed Grow Bloom
Week 1 2 3 4 1 2 3 4 5 6 7 8 9
Growth stage Seedling / Clone Early Growth Early Growth Late Growth Early Bloom Early Bloom Mid Bloom Mid Bloom Mid Bloom Late Bloom Late Bloom Ripen Flush
Total Nitrogen (ppm) 60 135 180 210 180 180 160 160 160 115 115 85 —
EC range (mS/cm) 0.6-0.8 1.3-1.5 1.7-2.1 2.0-2.5 2.0-2.4 2.0-2.4 1.9-2.4 1.9-2.4 1.9-2.4 1.3-1.6 1.3-1.6 0.9-1.1 —
PPM range (500 scale) 300-400 600-800 850-1050 1050-1250 1000-1200 1000-1200 950-1200 950-1200 950-1200 650-800 650-800 450-550 —
FloraMicro (ml/gal) 2.5 5.2 7.0 8.5 7.6 7.6 6.6 6.6 6.6 4.7 4.7 2.8 —
FloraGro (ml/gal) 2.5 4.8 6.5 8.0 6.6 6.6 6.6 6.6 6.6 4.7 4.7 2.8 —
FloraBloom (ml/gal) 2.5 3.7 4.8 6.0 8.5 8.5 9.5 9.5 9.5 5.7 5.7 4.5 —

Medium feed

Medium — All amounts per 3.79 liters (1 U.S. gallon)
Feed Grow Bloom
Week 1 2 3 4 1 2 3 4 5 6 7 8 9
Growth stage Seedling / Clone Early Growth Early Growth Late Growth Early Bloom Early Bloom Mid Bloom Mid Bloom Mid Bloom Late Bloom Late Bloom Ripen Flush
Total Nitrogen (ppm) 50 110 145 170 145 145 130 130 130 90 90 70 —
EC range (mS/cm) 0.5-0.6 1.0-1.2 1.3-1.6 1.6-2.0 1.6-1.9 1.6-1.9 1.6-1.9 1.6-1.9 1.6-1.9 1.0-1.3 1.0-1.3 0.7-0.9 —
PPM range (500 scale) 250-350 500-650 650-850 800-1000 800-1000† 800-1000† 800-1000 800-1000 800-1000 500-650 500-650 350-450 —
FloraMicro (ml/gal) 2.0 4.2 5.6 6.8 6.1 6.1 5.3 5.3 5.3 3.8 3.8 2.3 —
FloraGro (ml/gal) 2.0 3.8 5.2 6.4 5.3 5.3 5.3 5.3 5.3 3.8 3.8 2.3 —
FloraBloom (ml/gal) 2.0 3.0 3.8 4.8 6.8 6.8 7.6 7.6 7.6 4.5 4.6 3.6 —

Light feed

Light — All amounts per 3.79 liters (1 U.S. gallon)
Feed Grow Bloom
Week 1 2 3 4 1 2 3 4 5 6 7 8 9
Growth stage Seedling / Clone Early Growth Early Growth Late Growth Early Bloom Early Bloom Mid Bloom Mid Bloom Mid Bloom Late Bloom Late Bloom Ripen Flush
Total Nitrogen (ppm) 45 95 125 150 125 125 115 115 115 80 80 60 —
EC range (mS/cm) 0.4-0.5 0.9-1.1 1.2-1.4 1.4-1.7 1.4-1.7 1.4-1.7 1.4-1.7 1.4-1.7 1.4-1.7 0.9-1.1 0.9-1.1 0.6-0.8 —
PPM range (500 scale) 200-300 400-550 550-750 700-900 700-850 700-850 700-850 700-850 700-850 450-600 450-600 300-400 —
FloraMicro (ml/gal) 1.8 3.6 4.9 6.0 5.3 5.3 4.6 4.6 4.6 3.3 3.3 2.0 —
FloraGro (ml/gal) 1.8 3.4 4.6 5.6 4.6 4.6 4.6 4.6 4.6 3.3 3.3 2.0 —
FloraBloom (ml/gal) 1.8 2.6 3.4 4.2 6.0 6.0 6.6 6.6 6.6 4.0 4.0 3.2 —

† General Hydroponics' PDF prints 800-100 for the Medium PPM range at bloom weeks 1 and 2. Every other week in that row reads 800–1000, and 100 ppm at peak bloom is not a real target, so that is a typo in their file. We have published 800–1000 and flagged it rather than repeat the error.

A dash means the chart lists nothing for that week. On the flush week that means plain water — no nutrient.

Figures as published by General Hydroponics (document GH_FloraSeries_FeedCharts_WeeklyBasic_USD_200801). Feeding charts are recommendations only. Adjustments may be needed based on environmental conditions, your grow structure, and any additional products you run. Actual results vary.

Which strength should you run?

General Hydroponics splits these three ways by how fast your pots dry out. More irrigations a day means a weaker mix each time, because the plant sees the feed more often.

Aggressive

  • One irrigation event per day or fewer during peak production
  • Larger than a #5 pot, slow drybacks
  • Low planting density
  • Large, multi-topped cropping style

Medium

  • One to five irrigation events per day during peak production
  • #2 to #5 pot size, intermediate drybacks
  • Intermediate planting density
  • Intermediate, topped or pinched cropping style

Light

  • More than five irrigation events per day during peak production
  • 4 in, 6 in, #1 pot or block size, fast drybacks
  • High planting density
  • Small, untopped crops — sea of green style

Not sure which one you are? Bring us a photo of your setup and your pot size. That decision changes the numbers more than the brand does.

What the three bottles do

  • FloraMicro is used through both the growth and bloom cycles.
  • FloraGro builds strong roots during the vegetative stage.
  • FloraBloom is for fruit and flower development.

Always add FloraMicro to your reservoir first, and never mix concentrates together undiluted.

Download the original charts

The tables above cover the Flora Series 3-Part basic schedule. These are General Hydroponics' own PDFs, hosted here so the links do not rot:

What we stock

The Flora series, pH control, supplements and the propagation range. Not sure whether to run three-part or a one-part? Come in and we will talk through your water and your media first — that decision matters more than the brand. We are in Webster seven days a week and Milford Monday through Saturday, and we ship General Hydroponics nationwide.

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Everything on this schedule, stocked at Milford and Webster.

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