Kelp-derived 0-0-1 biostimulant for transition, bud set, and canopy vigor — foliar or drench.
Athena Stack is a liquid kelp-extract nutrient (0-0-1) formulated to support plant growth during the late-veg-to-early-flower transition window, promote lateral growth and bud development, and correct minor potassium deficiencies through foliar application or root drench. Part of Athena's Blended Line crop-protection and additive program.
Athena Stack is a liquid biostimulant and bloom-support additive built around Ascophyllum nodosum kelp extract — a cold-water brown alga that delivers bioavailable potassium alongside naturally occurring plant-support compounds including humic acids. The guaranteed analysis lists 1.0% soluble potash (K₂O) derived from kelp extract, with 0.45% humic acid also derived from kelp as a non-plant-food ingredient. That lean formulation is intentional: Stack is not a base fertilizer and is not meant to replace one. It runs alongside your complete nutrient program as a targeted input for a specific developmental window.
Because the formula contains organic kelp-derived ingredients, natural separation can occur during storage. Shake the container thoroughly before each use to ensure even distribution. Stack is safe for use in drip irrigation systems and does not require pH adjustment prior to application — a practical advantage in high-throughput facilities where spray prep time is a variable.
Stack is positioned within Athena's Blended Line as the organic root and flower enhancer — the additive that bridges the transition from vegetative growth into early flowering. The application window runs from the final week of vegetative growth through week 3 of flowering (some sources extend to week 4–5 for root-drench use), or until plants stop growing vertically. Timing the stop correctly matters: do not continue foliar applications past week 3 of flower.
In a facility running Athena's Blended Line (Grow A+B, Bloom A+B, CaMg, PK, Cleanse), Stack slots in as a weekly additive that supports the transition phase without disrupting the base EC program. For operators running the Pro Line dry concentrate system, Stack functions as the same transitional add-on — it is compatible across both Athena feeding frameworks. Athena's official feed charts include stage-specific guidance for Stack alongside the base nutrient schedule.
Stack can be deployed two ways depending on your program and facility setup. As a foliar spray, mix 7 mL per gallon of water and spray plants thoroughly once weekly. Always spray with high-intensity lights off and allow foliage to dry fully before lights come back on. As a root drench, mix 1–2 mL per gallon of water and apply once weekly as part of your regular fertigation mix — add Stack last to the reservoir. Both methods target the same developmental window; foliar application offers faster uptake for correcting minor potassium deficiencies, while the drench integrates cleanly into automated irrigation runs.
Two additional use cases: transplant stress reduction (2 mL per gallon, bare-root soak for 30–60 seconds or water-in after transplanting) and seed treatment (4 mL per gallon, soak seed 1–2 minutes before planting). These are secondary applications — the primary commercial use case is the transition-to-flower foliar or drench protocol.
One of the more operationally relevant features of Stack for commercial teams: it is fully compatible with Athena IPM in the same sprayer solution. Mixing both products for a single foliar pass — Stack delivering kelp-based biostimulant support, IPM providing broad-spectrum pest and pathogen defense — reduces both product waste and labor costs versus separate spray runs. Athena's official IPM + Stack procedure specifies adding IPM at 24 mL/L and Stack at 2 mL/L in RO water, agitating between additions.
This co-application window aligns with the same late-veg-to-early-flower timing Stack occupies on its own. For facilities managing spray programs on large canopy footprints, consolidating two weekly applications into one pass represents a meaningful labor efficiency — relevant whether you're running a single indoor room or a multi-zone cultivation facility. No pH adjustment is required for the combined solution.
| SKU | LQ-STK-1G |
| Brand | Athena |
| Product Line | Athena Blended Line (Crop Protection / Additives) |
| NPK (Guaranteed Analysis) | 0-0-1 |
| Soluble Potash (K₂O) | 1.0% |
| Non-Plant-Food Ingredients | 0.45% Humic acid derived from Kelp |
| Derived From | Kelp extract (Ascophyllum nodosum) |
| Container Size | 1 Gallon (also available in 32 oz and 5 Gallon) |
| Application Window | Final week of veg through week 3 of flower (foliar); up to week 4–5 (root drench) |
| Foliar Rate | 7 mL per gallon of water, once weekly |
| Root Drench Rate | 1–2 mL per gallon of water, once weekly |
| pH Adjustment Required | No |
Stack's guaranteed analysis is 0-0-1, meaning it contributes no nitrogen or phosphorus and delivers 1.0% soluble potash (K₂O). It is not a base fertilizer — it is a targeted potassium and biostimulant additive designed to run alongside your full nutrient program. At the application rates specified (1–2 mL/gal drench or 7 mL/gal foliar), it adds minimal EC impact while providing bioavailable kelp-derived compounds that support transition and bud development.
Yes. Athena officially supports co-application of Stack and IPM in the same foliar solution. The protocol is: add IPM at 24 mL/L and Stack at 2 mL/L in RO water, agitate between additions. Combining both products in a single weekly spray pass reduces labor and product waste without compromising the efficacy of either. Do not spray past week 3 of flower regardless of which products are in the tank.
Start Stack in the final week of vegetative growth and run it through the transition and into early flowering. For foliar applications, stop by the end of week 3 of flower. For root drench applications, the window extends to approximately week 4–5 of flowering, or once plants have stopped growing vertically. Starting too late or running it too deep into flower reduces its usefulness in the transition phase where it has the most documented impact.
Yes. Stack is listed as a Blended Line additive but it functions as a transitional add-on compatible with either Athena feeding framework. It is added last to the reservoir when drenching, and its organic kelp-derived formula does not interfere with the mineral base nutrients in either program. Refer to Athena's published feed charts for stage-specific rate guidance in your specific system.
Athena states Stack is safe for use in irrigation systems at labeled rates. The organic ingredients can separate in storage, so shake the container well before each use to resuspend solids before adding to your reservoir or spray tank. At the root drench rate of 1–2 mL per gallon, the concentration is low enough that buildup is not a documented issue, but as with any organic-derived additive, regular system maintenance and flushing protocols remain best practice.
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