Nutrient Mixing¶
A correctly mixed nutrient solution is the foundation for healthy plant growth. Kamerplanter automatically calculates EC budgets, scales manufacturer recipes, and validates the mixing order — preventing precipitations and wasted nutrients.
Mixing order matters
Always add CalMag first to the water before adding any other fertilizer — especially before sulfates and phosphates. Wrong order causes calcium sulfate precipitation (CaSO₄) and renders the solution ineffective.
Prerequisites¶
- EC meter (electrical conductivity meter)
- pH meter or test kit
- Known EC values for your water source (tap water or RO water)
- Fertilizers added in Kamerplanter under Master Data > Fertilizers
The EC Budget Model¶
Kamerplanter calculates how much electrical conductivity the fertilizers may still contribute — the EC budget:
| Variable | Meaning | Example |
|---|---|---|
EC_target | Desired final EC of the nutrient solution | 1.8 mS/cm |
EC_base_water | EC of the water used | 0.4 mS/cm |
EC_net | Remaining budget for fertilizers | 1.4 mS/cm |
RO water for maximum control
Reverse osmosis (RO) water typically has EC < 0.05 mS/cm, freeing the full EC budget for nutrients. Hard tap water with high Ca/Mg content significantly reduces the available budget.
The 3-Stage EC Budget Pipeline¶
Kamerplanter applies a structured 3-stage calculation:
Stage 1 — Water Mix (EC_mix)¶
When blending RO and tap water, Kamerplanter first calculates the EC of the blend:
Example: 50 % RO (EC 0.02) + 50 % tap water (EC 0.50):
Stage 2 — EC Allocation (Budget Segments)¶
The net EC budget is divided into segments in this order:
| Segment | Priority | Description |
|---|---|---|
| Silica | 1 (first deduction) | Optional silicate is pre-calculated |
| CalMag | 2 | Calcium-magnesium solution (essential for coco/hydro) |
| pH Reserve | 3 | Buffer for pH adjuster (0.02–0.05 mS depending on water hardness) |
| Base Nutrients | 4 | Remaining budget distributed to base nutrients |
Stage 3 — Recipe Scaling¶
When manufacturer recipes (ml/L per fertilizer) are stored in Kamerplanter, the system scales proportionally:
Without recipe data: the EC budget is distributed equally across all base fertilizers.
Mixing Order — Step by Step¶
The mixing sequence is critical. Kamerplanter automatically generates a numbered mixing guide:
1. Fill container with [X] liters of water
2. Add silica — stir vigorously, wait 5 minutes
3. Add CalMag — mix thoroughly
4. Add base nutrient A — stir
5. Add base nutrient B — stir
6. Adjust pH to target — stir, wait 5 minutes
7. Verify final EC reading
Why silica before CalMag?
Silicate ions (SiO₄²⁻) form poorly soluble calcium silicate (CaSiO₃) with calcium ions (Ca²⁺). Therefore silica must go into the water before CalMag — otherwise the active ingredient precipitates out.
Incompatibilities and Safety Validation¶
Kamerplanter automatically checks the following combinations:
| Combination | Risk | Severity |
|---|---|---|
| CalMag + Sulfates (e.g. Epsom) | Gypsum precipitation (CaSO₄) | Critical |
| CalMag + Phosphates | Calcium phosphate precipitation | Critical |
| Silica + CalMag (wrong order) | CaSiO₃ precipitation | Critical |
| Iron chelate + pH > 7 | Chelate destabilizes | Warning |
| Foliar-only + fertigation products | Wrong application method | Note |
Act on critical warnings immediately
If a red warning appears in the mixing guide, stop immediately and check the fertilizer combination. A precipitated solution cannot be recovered — complete remixing is required.
EC Target Values by Phase and Substrate¶
Kamerplanter validates the calculated final EC against phase- and substrate-specific maximum values:
| Substrate | Seedling (mS) | Vegetative (mS) | Flowering (mS) | Flushing (mS) |
|---|---|---|---|---|
| Hydroponics | 0.8 – 1.2 | 1.6 – 2.4 | 1.8 – 2.8 | 0.0 – 0.3 |
| Coco | 0.8 – 1.0 | 1.6 – 2.0 | 1.8 – 2.4 | 0.0 – 0.3 |
| Soil | 0.4 – 0.6 | 0.8 – 1.4 | 1.0 – 1.6 | 0.0 – 0.3 |
Fresh coco: automatic CalMag boost
For freshly set-up coco batches (0 cycles used), Kamerplanter automatically increases the CalMag dose by 20 %, since unused coco absorbs calcium and magnesium from the solution (cation exchange).
Setting pH¶
After mixing all nutrients, measure and correct the pH:
| Substrate | Target pH Range | Note |
|---|---|---|
| Hydroponics | 5.5 – 6.0 | Optimum nutrient availability |
| Coco | 5.8 – 6.2 | Slightly higher than hydro |
| Soil | 6.0 – 6.8 | Consider microbial activity |
| Living Soil | 6.2 – 7.0 | pH buffered by soil biology |
Kamerplanter instructs whether pH Up (potassium hydroxide) or pH Down (phosphoric acid) is needed.
Always adjust pH last
pH corrections must be performed as the final step — after all nutrients have been mixed in. Nutrients change the pH and may require a second adjustment.
Runoff Analysis¶
In drain-to-waste operation (coco, rockwool), runoff analysis provides important feedback:
| Measurement | Target Range | Deviation → Action |
|---|---|---|
| Runoff EC − Input EC | ±0.3 mS/cm | > +0.5: salt buildup → flush |
| Runoff pH − Input pH | ±0.5 | > ±0.5: check substrate buffering |
| Runoff volume / Input | 10 – 30 % | < 10 %: increase water volume |
Typical flush signal
Runoff EC = 2.8 mS, input EC = 2.0 mS → delta = +0.8 mS (exceeds threshold of 0.5). Kamerplanter recommends 1–2 flush cycles with clean water (EC < 0.3 mS, pH 6.0).
Pre-Harvest Flushing¶
Kamerplanter automatically calculates a flushing schedule. Recommended flush duration depends on substrate:
| Substrate | Recommended Flush Duration |
|---|---|
| Hydroponics | 7 – 14 days |
| Coco | 10 – 21 days |
| Rockwool | 7 – 14 days |
| Soil | 14 – 30 days |
Flushing protocol (3-phase reduction):
| Time segment (% of flush period) | Target EC | Action |
|---|---|---|
| First 30 % | 50 % of original EC | Reduced nutrient solution |
| Middle 30 % | 25 % of original EC | Quarter-strength |
| Final 40 % | 0.0 mS/cm | Plain water only |
Water Temperature¶
Water temperature affects solubility and biological effectiveness:
| Temperature | Assessment |
|---|---|
| < 5 °C | Too cold — poor dissolution, precipitation risk |
| 5 – 18 °C | Suboptimal — stir longer |
| 18 – 22 °C | Optimal |
| 22 – 30 °C | Acceptable — biological products may degrade faster |
| > 35 °C | Not suitable for biological fertilizers |
Frequently Asked Questions¶
My solution is white / cloudy after mixing — what happened?
Cloudiness indicates precipitation. Most common cause: CalMag was added after a sulfate or phosphate. Discard the solution, rinse the container with warm water, correct the mixing order, and start fresh.
Can I add all fertilizers at the same time?
No. CalMag and sulfate/phosphate must not come into contact simultaneously — this immediately causes precipitation. Always add step by step and stir between additions.
How often should I measure EC and pH of the finished solution?
Always immediately after mixing. For tank/reservoir systems, check daily — EC rises as water evaporates and pH drifts due to plant metabolism.
What does 'not tank-safe' mean for a fertilizer?
Fertilizers that are not tank-safe must not be stored in a reservoir over extended periods — they decompose or precipitate. They must be mixed fresh before each application.