Regime
Estimative Index (EI)
Philosophy
The Estimative Index, developed by Tom Barr, starts from a simple principle: if you provide nutrients in excess, deficiencies cannot be the cause of plant problems.
The weekly 50% water change resets concentrations and prevents dangerous buildup. It's an aggressive but effective approach for high-tech tanks with rapid growth.
Recommended nutrient targets
| Parameter | mg/L |
|---|---|
| N (NO₃) | 20 |
| P (PO₄) | 2 |
| K | 30 |
| Fe | 0.5 |
| Mg | 5 |
| Ca | 20 |
| B | 0.02 |
| Mn | 0.5 |
| Zn | 0.03 |
| Cu | 0.01 |
| Mo | 0.003 |
Dosing frequency
3x/week macros (Mon-Wed-Fri), 3x/week micros (Tue-Thu-Sat)
Water change
50% weekly (mandatory)
CO₂
Pressurized recommended (30 mg/L target)
Light
Medium-high (40-80+ PAR at substrate)
Pros
- Eliminates deficiency as a variable
- Rapid, lush growth
- Simple to calculate
- Well documented by the community
Cons
- Weekly water change mandatory
- High fertilizer consumption
- Algae risk if light/CO2 unbalanced
- Not suitable for low-tech
Common Errors
- •(EN) Content pending...
Advanced Techniques
- •(EN) Content pending...
Ideal for
High-tech planted tanks with pressurized CO2, intense light, and regular water changes. Ideal for aquascapers seeking maximum growth.