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Electrical Conductivity & pH
Table 1: Optimum range of electrical conductivity (EC) and pH values for hydroponic crops.
| Crops | EC (mS/cm) | pH |
|---|---|---|
| Asparagus | 1.4 to 1.8 | 6.0 to 6.8 |
| African Violet | 1.2 to 1.5 | 6.0 to 7.0 |
| Basil | 1.0 to 1.6 | 5.5 to 6.0 |
| Bean | 2.0 to 4.0 | 6 |
| Banana | 1.8 to 2.2 | 5.5 to 6.5 |
| Broccoli | 2.8 to 3.5 | 6.0 to 6.8 |
| Cabbage | 2.5 to 3.0 | 6.5 to 7.0 |
| Celery | 1.8 to 2.4 | 6.5 |
| Carnation | 2.0 to 3.5 | 6 |
| Courgettes | 1.8 to 2.4 | 6 |
| Cucumber | 1.7 to 2.0 | 5.0 to 5.5 |
| Eggplant | 2.5 to 3.5 | 6 |
| Ficus | 1.6 to 2.4 | 5.5 to 6.0 |
| Leek | 1.4 to 1.8 | 6.5 to 7.0 |
| Lettuce | 1.2 to 1.8 | 6.0 to 7.0 |
| Marrow | 1.8 to 2.4 | 6 |
| Okra | 2.0 to 2.4 | 6.5 |
| Pak Choi | 1.5 to 2.0 | 7 |
| Peppers | 0.8 to 1.8 | 5.5 to 6.0 |
| Parsley | 1.8 to 2.2 | 6.0 to 6.5 |
| Rhubarb | 1.6 to 2.0 | 5.5 to 6.0 |
| Rose | 1.5 to 2.5 | 5.5 to 6.0 |
| Spinach | 1.8 to 2.3 | 6.0 to 7.0 |
| Strawberry | 1.8 to 2.2 | 6 |
| Sage | 1.0 to 1.6 | 5.5 to 6.5 |
| Tomato | 2.0 to 4.0 | 6.0 to 6.5 |
Electrical Conductivity & pH Guide
Hydroponic Recipes
Table 2: Target nitrogen feed rates (in ppm N) for several hydroponic crops.
| Type | Propagation (ppm N) | Production (ppm N) |
|---|---|---|
| Buttercrunch/Boston Bibb | 125 | 150 |
| Romaine, Red and Green leaf | 125 | 150 |
| Basil | 125 | 175 |
| Culinary Herbs | 125 | 150 |
| Cole Crops | 125 | 175 |
| Garlic and Scallions | 125 | 150 |
| Tomatoes | 125 | 200 |
| Peppers | 125 | 150 |
| Cucumber | 125 | 175 |
| Heavy Feeders (cabbage, kale, spinach, Swiss chard, mustard greens, mizuna, escarole) | 125 | 175–200 |
| Light Feeder Lettuce (arugula, watercress, spring mix) | 125 | 125–150 |