🪣 Tank & Solution Parameters
🧪 Macro Solution — Salts for Bottle
Dissolve in RO or distilled water. Top up to your chosen solution volume.
Dose per addition
⚗️ Micro Solution — Salts for Bottle
Mix separately from macros. Store in dark bottle.
Dose per addition
Low Tech EI Notes: Standard EI is reduced by ~50% for low tech/no CO₂ tanks. Plants absorb nutrients more slowly without CO₂ enrichment, so lower doses prevent algae from excess nutrients. A 50% weekly water change resets nutrient levels and prevents salt build-up.
⚖️ Tank Parameters — Dry Dosing
🧂 Macro Dry Doses — per addition
🔬 Micro Dry Doses — per addition
⚠️ Dry dosing tip: Always pre-dissolve salts in a small cup of tank water before adding, especially iron chelate (DTPA/EDTA) which can cause localised precipitation. Never dose macros and micros simultaneously — wait at least 30 minutes between them.
📋 Complete Ingredients List
Macronutrient Salts
| Chemical | Formula | Nutrients Supplied | Source |
|---|---|---|---|
Potassium Nitrate KNO₃ |
KNO₃ | Nitrogen (N), Potassium (K) | Garden / hydro supplier |
Potassium Phosphate (Mono) KH₂PO₄ |
KH₂PO₄ | Phosphorus (P), Potassium (K) | Aquatic/hydro supplier |
Potassium Sulphate K₂SO₄ |
K₂SO₄ | Potassium (K), Sulphur (S) | Garden / hydro supplier |
Magnesium Sulphate MgSO₄·7H₂O |
Epsom Salt | Magnesium (Mg), Sulphur (S) | Pharmacy / garden centre |
Micronutrient / Trace Salts
| Chemical | Formula | Nutrients Supplied | Notes |
|---|---|---|---|
Iron DTPA Chelate Fe-DTPA 11% |
Fe | Iron (Fe) — chelated | Stable up to pH 7.5 |
Manganese Sulphate MnSO₄·H₂O |
Mn | Manganese (Mn) | Hydro/aquatic supplier |
Zinc Sulphate ZnSO₄·7H₂O |
Zn | Zinc (Zn) | Hydro supplier |
Copper Sulphate CuSO₄·5H₂O |
Cu | Copper (Cu) | ⚠️ Toxic to inverts at high doses |
Sodium Molybdate Na₂MoO₄·2H₂O |
Mo | Molybdenum (Mo) | Very small amounts needed |
Boric Acid H₃BO₃ |
B | Boron (B) | Pharmacy / hydro supplier |
Alternative — Pre-mixed Trace: Instead of mixing individual trace salts, you can use a commercial trace mix such as CSM+B (Plantex CSM+B) which contains all micronutrients in correct ratios. Use at ~0.3–0.5g per 100L per week for low tech. This simplifies the micro solution significantly.
Sourcing (UK): Aquarium Plant Food, Aquatic Magic, Nutrimaster, or general hydroponic suppliers. KNO₃ may require ID in some UK stores — food-grade or horticultural grade is fine. Never use hardware store grade chemicals.
📅 Recommended Dosing Schedule
Standard EI rotation for low tech tanks — alternating macros and micros prevents precipitation. Adjust days to suit your routine.
Schedule Logic:
Macros (N, P, K) and micros (trace elements) are dosed on alternate days to prevent iron and phosphate from precipitating out of solution. The large weekly water change (≥50%) resets nutrient accumulation and keeps the tank in balance — this is the cornerstone of the EI method.
Macros (N, P, K) and micros (trace elements) are dosed on alternate days to prevent iron and phosphate from precipitating out of solution. The large weekly water change (≥50%) resets nutrient accumulation and keeps the tank in balance — this is the cornerstone of the EI method.
📊 Target Nutrient Ranges — Low Tech EI
| Nutrient | Target (ppm) | Role |
|---|---|---|
| Nitrate (NO₃) | 5–15 | Primary nitrogen source |
| Phosphate (PO₄) | 0.5–1.5 | Cell energy, metabolism |
| Potassium (K) | 5–15 | Ion regulation, photosynthesis |
| Magnesium (Mg) | 2–5 | Chlorophyll production |
| Iron (Fe) | 0.05–0.1 | Enzyme co-factor |
| Manganese (Mn) | 0.01–0.05 | Photosystem II |