Growth Science Opulent Harvest

Growth Science Organics Opulent Harvest is a 0-0-3 organic potassium supplement built for the transition and bloom phases. Fermented plant materials, four kelp species, and fulvic acid deliver natural potassium plus phytochemicals that support flower density, aroma, and oil production in soil, coco, and hydroponic crops. This listing is the 1-quart (1 L) size, SKU GSOOHQ.

Opulent Harvest Specifications

The numbers below describe the 1-quart (1 L) bottle of Growth Science Organics Opulent Harvest distributed by Hydrofarm. Values are drawn from supplier and retailer datasheets for this specific size.

Specification	Value
Product line	Growth Science Organics Opulent Harvest
Supplier SKU	GSOOHQ
Container size	1 Quart (1 L)
Guaranteed analysis (NPK)	0-0-3
Product type	Organic potassium bloom supplement (liquid)
Shipping weight	3.50 lb
Key inputs	Fermented nettle, comfrey, dandelion, horsetail, alfalfa; four kelp species; fulvic acid
Certifications	CDFA OIM, WSDA-Registered, Clean Green Certified, OMRI Listed
Application methods	Foliar spray (early flower) and root drench / fertigation
Other available sizes	1 gal, 2.5 gal, 6 gal, 55 gal, 275 gal tote
Brand / distributor	Growth Science Organics (distributed by Hydrofarm)

Why Choose Opulent Harvest

Opulent Harvest is a focused tool, not a complete bloom base. Its job is to deliver natural potassium and a stack of plant-derived co-factors during the window where potassium demand is highest: late stretch into mid-bloom. The formula is built from fermented botanicals rather than mineral salts, which changes both what the plant receives and how the substrate responds.

• Potassium without added phosphorus. The 0-0-3 profile lets you push potassium independently of P, which is useful when your base nutrient already covers phosphorus or when you are running an organic program that prefers slow-release P from amendments.
• Biodynamic ferments as the active base. Growth Science ferments nettle, comfrey, dandelion, horsetail, and alfalfa to extract mineral compounds and novel phytochemicals from the parent plant material — inputs that are difficult to replicate with a synthetic salt blend.
• Four kelp species, not one. Multiple kelp inputs add a broader range of carbohydrates and trace compounds to the soil or substrate, feeding microbial life around the root zone in addition to the plant itself.
• Fulvic acid built in. Fulvic acid chelates micronutrients, which improves uptake efficiency of the iron, manganese, zinc, and other trace elements already present in your feed or substrate.
• Multiple organic certifications. CDFA OIM, WSDA-Registered, Clean Green Certified, and OMRI Listed status make Opulent Harvest usable in licensed organic and clean-certified commercial programs without paperwork friction.
• Two application paths. The same bottle works as a foliar spray during early flower and as a root drench through bloom and late bloom, which simplifies inventory for growers who run both delivery methods.

Best Uses for Opulent Harvest

Opulent Harvest is built for the back half of the crop cycle in flowering and fruiting plants. The grow scenarios below match how commercial and serious home growers typically schedule a potassium-focused organic supplement.

• Transitioning from veg to flower. Bring Opulent Harvest in as soon as the plant signals stretch is ending and flower sites are setting. The added potassium supports flower initiation while the ferment-derived phytochemicals help the plant adapt to the new photoperiod or hormonal shift.
• Mid-bloom flower fill. During weeks 3–5 of a typical 8-week flower cycle, potassium demand climbs as flowers gain weight. Opulent Harvest is dosed at 10–15 ml per gallon through this window to support density and structure.
• Late-bloom finishing. In the final stretch before flush, the dose ramps to 15 ml per gallon to help carry flowers through ripening with full potassium availability.
• Organic and certified-clean programs. Licensed organic operators, Clean Green farms, and OMRI-compliant home growers can run Opulent Harvest without breaking certification chain-of-custody.
• Mixed-substrate gardens. Soil, coco, and recirculating or run-to-waste hydroponic systems all accept the product; the fulvic acid component helps in mineral-light substrates where micronutrient lock-out is a risk.
• High-value flower and fruit crops. Cannabis, tomatoes, peppers, strawberries, and ornamental flowers benefit from the aroma, oil, and terpene support that potassium and kelp-derived inputs provide during ripening.

Opulent Harvest vs General Organics Kool Bloom

The closest mass-market comparison for Opulent Harvest is General Hydroponics’ General Organics Kool Bloom, a widely stocked 0-10-10 organic bloom booster. The two products solve adjacent problems and the choice between them depends on what your base feed is already delivering.

Kool Bloom is a combined P-K booster: it brings phosphorus and potassium together in a single bottle, which is useful when your base nutrient is light on both. Opulent Harvest takes the opposite approach — pure potassium at 0-0-3, plus a botanical ferment and four-kelp ingredient base. If you are already running an organic bloom base that covers phosphorus (most do), stacking a 0-10-10 booster on top can overshoot P, which Opulent Harvest avoids by design. Opulent Harvest also carries OMRI, CDFA OIM, WSDA, and Clean Green certifications that Kool Bloom does not, which matters for licensed organic operations.

A second comparison worth noting is Real Growers Big Swell, a potassium silicate bloom booster aimed at terpene and resin development. Big Swell uses mineral silicate chemistry; Opulent Harvest uses fermented botanicals plus kelp. Big Swell does not carry the same stack of organic certifications. If you are blending Opulent Harvest into a wider organic program, you may also be running pH-balancing or full-bloom inputs alongside it — see our Advanced Nutrients pH Perfect Sensi Bloom Part A listing for one common pH-stabilised bloom base that pairs with potassium supplements like this one.

Compatibility

Opulent Harvest is formulated to slot into a broad range of bloom programs and delivery systems without special handling beyond standard liquid-nutrient practice.

• Substrates: Soil, coco coir, peat-based mixes, and recirculating or run-to-waste hydroponic systems. The product is liquid and water-soluble at recommended dose rates.
• Delivery systems: Hand-watering, drip irrigation, fertigation lines, and automated injectors. The product is documented as compatible with Dosatron and similar fertilizer-injector systems for commercial-scale dosing.
• Foliar sprayers: Standard pump or backpack sprayers work; use during the first two weeks of flower before flowers begin to mature, then switch to root drench only.
• Base nutrient programs: Designed as a supplement, not a stand-alone feed. Use alongside your existing veg-to-bloom base nutrient line; Opulent Harvest does not replace a balanced N-P-K base.
• Grow environments: Indoor tents, sealed rooms, greenhouses, and outdoor beds. Storage in a tent or grow space is best inside a sealed container at moderate temperature. If you are tracking finished flower storage humidity after harvest, the same kind of sealed-environment thinking applies — see our CVault storage containers for one option.
• Certified programs: Compatible with CDFA OIM, WSDA-Registered, Clean Green Certified, and OMRI-listed cultivation requirements.

Dosing Guidelines

Dose Opulent Harvest by growth stage. The rates below come from the manufacturer’s published application chart. All rates assume mixing into already pH-adjusted base water alongside your standard bloom feed; adjust EC and pH after addition as you would with any liquid supplement.

Growth stage	Dose	Method
Transition to flower	10 ml per gallon	Root drench at each feed
Bloom (weeks 1–4 of flower)	10–15 ml per gallon	Root drench at each feed
Late bloom (final 2–3 weeks before flush)	15 ml per gallon	Root drench at each feed
Foliar (first 2 weeks of flower only)	10 ml per gallon	Foliar spray, 1–2 times weekly
Final week	Discontinue; flush with pH-balanced water	Plain water at pH 6.2–6.5

Stop foliar applications once flowers begin to mature — wet flower tissue invites mold and the spray no longer reaches efficient absorption surfaces. Continue root drench applications through bloom and late bloom, then transition to plain pH-balanced water for the final week to clear residual feed before harvest.

How to Use Opulent Harvest

The steps below cover a standard fertigation cycle with Opulent Harvest as a bloom-stage supplement to your existing base feed.

1. Shake the bottle thoroughly before measuring. Ferment-based products can settle in storage; a full shake redistributes the active inputs.
2. Prepare your reservoir or mixing tank with the volume of water you need for the feed cycle. Filtered or RO water is preferred where source-water chemistry is heavy or inconsistent.
3. pH-adjust the base water to your target range before adding nutrients (5.8–6.2 for hydroponic and coco; 6.2–6.5 for soil).
4. Add your standard base bloom nutrient first and mix to dissolve.
5. Measure Opulent Harvest at the dose rate for your current growth stage (10 ml/gal transition, 10–15 ml/gal bloom, 15 ml/gal late bloom) using a calibrated syringe or measuring cup.
6. Add Opulent Harvest to the reservoir and mix thoroughly. Verify final pH and EC; small post-addition adjustments are normal.
7. Apply via your standard delivery method — hand-watering, drip, or injector. For foliar use during the first two weeks of flower, spray to runoff in early morning or late evening when lights are low and stomata are open.
8. Discontinue Opulent Harvest in the final week before harvest and switch to plain pH-balanced water (6.2–6.5) to flush residual feed.
9. Observe plant response week-over-week. If runoff EC trends high or leaf tips show salt stress, reduce the next dose by 25% and re-evaluate.

Sources & Further Reading