2HR Aquarist APT EI is a ready-to-use, all-in-one liquid fertilizer built on the famous Estimative Index method pioneered by Tom Barr — the dosing philosophy of giving plants a generous, non-limiting supply of every nutrient so growth is never held back. It delivers all three macronutrients (nitrogen, phosphorus, potassium) plus iron and a full suite of trace minerals, in the right proportions, with no guesswork or DIY salt-mixing.
Where It Fits: APT EI is the choice for plant-heavy, higher-tech tanks — lots of plants, strong light, CO₂, and relatively few fish — where demanding stem plants and carpets burn through nutrients fast. (For tanks with more fish and fewer plants, 2HR's lower-nutrient APT formulas are a better match.) It's formulated for richer coloration and algae control compared to a conventional EI mix.
As 2HR emphasizes, plants take weeks to adapt to better nutrition — watch for improvement in new growth rather than expecting old leaves to recover, and keep the tank stable while they adjust.
Dosing Guidelines: Dose per the label for your tank size and plant load, typically several times a week; the calibrated pump delivers 1 mL per press for easy, repeatable dosing. Pair with good CO₂ and a regular water-change routine for best results. Available in 300 mL, 500 mL, and 1000 mL.
Inventory Accuracy
If this item is at low stock, or you are ordering all or almost all of our current inventory, there may be an inventory discrepency. We will contact you about any issues as soon as possible.
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Pipersville, PA 18947
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