2Hr Aquarist APT Estimative Index (APT EI) – High-Performance Aquarium Plant Fertilizer

Expert-Grade EI Dosing Made Easy

The 2Hr Aquarist APT Estimative Index (APT EI) delivers the powerful, proven EI nutrient dosing method in a ready-to-use liquid concentrate. Based on the renowned approach pioneered by Tom Barr, APT EI provides advanced aquascapers with the ultimate control over plant nutrition—without the guesswork.

Designed for heavily planted tanks and experienced aquarists, APT EI is ideal for high-growth setups where maximum nutrient availability is critical for optimal plant performance.

Why Choose APT Estimative Index?

• Pre-mixed EI formula based on Tom Barr’s proven method

• Delivers a full spectrum of macronutrients and micronutrients in precise EI ratios

• Supports robust plant growth, vibrant coloration, and algae resistance

• Includes a calibrated pump for easy, accurate dosing

• Ideal for Dutch-style tanks and advanced aquascaping setups