Kelp-extract transition and bloom support — foliar or root drench, once weekly.
Athena Stack (0-0-1) is a liquid kelp-based plant nutrient derived from Ascophyllum nodosum, formulated to support plant development through the transition into flower and into early-to-mid bloom. Applied as a foliar spray or root drench once weekly, it delivers soluble potash and humic acid alongside the base feed program without requiring a separate pH adjustment.
Athena Stack is a single-ingredient-focused liquid supplement built around kelp concentrate (Ascophyllum nodosum). Its guaranteed analysis is 0-0-1, meaning the plant food contribution is 1.0% soluble potash (K₂O) derived from kelp extract. The label also carries 0.45% humic acid derived from kelp — a non-plant-food ingredient that supports uptake. That simplicity is intentional: Stack slots into the Athena Blended Line program as a targeted enhancer rather than a second base nutrient, sitting alongside Grow A+B or Bloom A+B rather than replacing either.
Stack is part of Athena's crop protection and supplemental range, manufactured by Athena Ag in Los Angeles, CA under ISO 9001 quality management. Athena formulates and produces their full lineup in-house, which keeps batch consistency tight — a meaningful detail when you're running automated fertigation across multiple zones.
Stack is aimed at licensed commercial cannabis and hemp cultivators running the Athena Blended Line program who want a clean, low-input supplement during the vegetative-to-flower transition window. If your rooms are running high light intensity and tight environmental targets, the abiotic stress tolerance support that kelp-derived cytokinins and naturally occurring growth compounds provide can matter most precisely when plants are being pushed hardest — stretch phase through early flower set.
It's equally relevant for operators who are already running Athena IPM as part of their foliar program. Stack is fully compatible with Athena IPM and can be mixed into the same sprayer for a combined pass, cutting labor on spray days. Growers dealing with recurring minor potassium deficiencies during heavy demand phases — a common presentation in high-EC programs — can also use Stack as a targeted corrective via foliar for faster uptake.
Athena recommends applying Stack from the final week of vegetative growth through week 4–5 of flower, or until plants stop growing vertically. After that transition window closes, foliar application should stop — do not spray past week 3 of flower. Root drench continues through the flowering window per the feed schedule.
For foliar application: mix 7 mL per gallon of water and spray canopy thoroughly once weekly. Apply with lights off and allow foliage to dry before lights return. For root drench: mix 1–2 mL per gallon of water, add Stack last to the reservoir after base nutrients are mixed. Stack is safe for use in drip, recirculating, and run-to-waste irrigation systems. For transplant events, mix 2 mL per gallon and soak bare root for 30–60 seconds or water in after transplant. For seed treatment, 4 mL per gallon — soak for 1–2 minutes before planting.
Stack contains organic ingredients and will naturally separate in storage. Shake thoroughly before each use. No pH adjustment is required after addition at recommended rates.
Stack is not a PK booster and is not a replacement for Athena's PK additive (0-4-5) during mid-to-late flower. The 0-0-1 NPK positions it squarely as a transition-window biostimulant and minor-deficiency corrective — the kind of input that holds plants steady through the stretch without loading additional phosphorus or nitrogen at a stage where you want those inputs controlled.
Commercial operators running constant-EC programs on the Pro Line or Blended Line have a clean integration path: Stack's low input volume (1–2 mL/gal drench) does not materially shift reservoir EC, so it layers into the base program without forcing recipe adjustments. For large-canopy rooms running automated dosing, the low dose rate also means a 32 oz bottle goes further than the container size suggests — calculate your weekly reservoir volume and dose accordingly before ordering quantity.
Available through Hydro Supply Co. for licensed cannabis and hemp operators nationwide. Request a quote below for commercial volume pricing.
| SKU | LQ-STK-32OZ |
| Brand | Athena (Athena Ag, Los Angeles, CA) |
| NPK | 0-0-1 |
| Soluble Potash (K₂O) | 1.0% |
| Humic Acid (non-plant-food) | 0.45% (derived from kelp) |
| Derived From | Kelp extract (Ascophyllum nodosum) |
| Container Size | 32 oz (946 mL) |
| Application Methods | Foliar spray, root drench, transplant drench, seed soak |
| Foliar Rate | 7 mL per gallon, once weekly |
| Root Drench Rate | 1–2 mL per gallon, once weekly |
| Application Window | Final week of veg through week 4–5 of flower (foliar: stop at week 3 flower) |
| pH Adjustment Required | No |
Stack is formulated as part of Athena's Blended Line program, but its simple kelp-extract composition means it can be layered into other base programs. That said, Athena publishes and supports feed schedules specifically for Blended Line integration — if you're running a different base, mix on a trial reservoir first to confirm compatibility and check for any EC or pH shift before scaling.
They serve different roles in the program. Stack is a 0-0-1 kelp-derived biostimulant used during the transition window (late veg through mid-flower) for abiotic stress support, potassium deficiency correction, and plant development. Athena PK is a 0-4-5 phosphorus-and-potassium bloom booster applied mid-to-late flower to drive bulk and density. They're not interchangeable — Stack runs early, PK runs later.
Yes. Athena confirms Stack is fully compatible with Athena IPM and can be applied simultaneously from the same sprayer. Both are applied once weekly in the foliar window, so a combined pass is a practical way to reduce spray labor on commercial canopy.
No — Stack contains organic kelp-derived ingredients that naturally separate during storage. This is normal and expected. Shake the bottle thoroughly before every use to re-homogenize before measuring your dose.
Athena Stack is available in multiple sizes including 32 oz, 1 gallon, and 5 gallon. Contact Hydro Supply Co. for commercial volume availability and quote on the size that fits your program scale.
Get operator-direct pricing and availability. We supply licensed commercial cultivators nationwide.
Request a Quote