Every new grower asks the same question: "How much should I feed?" The honest answer is less than you think. Overfeeding causes more problems than underfeeding, and the best feeding schedule is one that responds to what the plant tells you — not what the bottle says.
The universal feeding principle
Start at 50% of the manufacturer's recommendation. Then adjust based on what the plant shows you. If tips stay green and growth is vigorous, you can creep up. If leaf tips burn, back off. This applies to every nutrient line — General Hydroponics, Jack's, Canna, Advanced Nutrients, Fox Farm, Athena, all of them.
Nutrient companies want you to use more product. Their feed charts are marketing, not agronomy.
Understanding N-P-K
Every nutrient label shows three numbers: N-P-K (Nitrogen-Phosphorus- Potassium). These are the macronutrients — the big three.
| Nutrient | Primary role | When the plant wants most |
|---|---|---|
| Nitrogen (N) | Leaf and stem growth | Veg through early flower |
| Phosphorus (P) | Root development, flower formation | Mid-to-late flower |
| Potassium (K) | Water regulation, enzyme activation | All stages, peak in flower |
Veg = higher N, moderate P and K Flower = lower N, higher P and K
That's the entire concept. Everything else is details.
The feed-water-feed cycle
For soil and coco growers, alternating between feed and plain water prevents salt buildup:
- Feed (nutrients at your target strength)
- Water (plain pH'd water)
- Feed (nutrients)
- Water (plain pH'd water)
- Repeat
In living soil, you don't feed at all — the biology does it. In hydro, the reservoir is always nutrient-charged, so this cycle doesn't apply.