FoxFarm Big Bloom Liquid Concentrate – Gal

FoxFarm Big Bloom Liquid Concentrate is a one-gallon bottle of organic-based liquid plant food built around bat guano and earthworm castings. It is formulated to support multiple blooms and seed formations across all fruiting and flowering plants, and it can be used at every stage of growth — from seedling through late bloom.

FoxFarm Big Bloom Liquid Concentrate Specifications

The table below lists confirmed specifications drawn from the canonical product data and product labeling. The NPK values (0–0.5–0.7) are drawn from distributor catalog data for SKU FX14003.

Specification	Value
Brand	FoxFarm (distributed by Hydrofarm)
Supplier SKU	FX14003
Size / Volume	1 Gallon (128 fl oz)
NPK Analysis	0 – 0.5 – 0.7
Primary Ingredients	Bat guano, earthworm castings
Formula Type	Liquid concentrate
Application Stage	All stages (seedling through late bloom)
Weight (shipping)	10.0 lb
Target Crops	All fruiting and flowering plants

Why Choose FoxFarm Big Bloom Liquid Concentrate

FoxFarm Big Bloom is designed around organic nutrient sources that growers have relied on for generations. Here is what distinguishes it from synthetic bloom additives:

• Bat guano as the backbone. Bat guano has been used as a plant fertilizer for centuries. It delivers phosphorus and micronutrients in a form that breaks down in the root zone, making nutrients accessible to plants relatively quickly compared to slow-release dry amendments.
• Earthworm castings for biological activity. Earthworm castings contribute a range of trace minerals and beneficial microbial life that support healthy soil structure and root development. When combined with bat guano, they create a nutrient-dense blend suited to both soil and soilless media that include organic matter.
• Immediate nutrient availability in liquid form. Because Big Bloom is a liquid concentrate, nutrients go into solution readily. This means plants can access them in the same watering cycle rather than waiting for solid amendments to break down.
• Versatile across growth stages. Unlike many bloom boosters that are restricted to the flowering window, Big Bloom is labeled for all stages of plant growth. This reduces the number of separate products a grower needs to manage and allows consistent use from transplant through harvest.
• One-gallon size for extended runs. The gallon format supplies enough concentrate for multiple feeding cycles in a mid-to-large grow, reducing reorder frequency compared to quart or smaller bottles.

Best Uses for FoxFarm Big Bloom Liquid Concentrate

Big Bloom fits naturally into several growing scenarios. The following use cases are drawn directly from the product’s formulation and stated labeling:

• Bloom support for fruiting crops. The primary purpose of Big Bloom is to support multiple bloom cycles and seed formations in fruiting plants such as tomatoes, peppers, cucumbers, and squash. The phosphorus-leaning NPK (0–0.5–0.7) aligns with the nutrient ratios plants typically draw during flower initiation and fruit set.
• All-stage base additive in organic programs. Because Big Bloom is formulated for use from seedling through late bloom, it can serve as a consistent background supplement in an organic nutrient program. Growers working with living-soil beds or coco coir often add it throughout the cycle rather than switching products at each phase.
• Supplementing base nutrients in soil or soilless media. Big Bloom pairs well with a primary three-part nutrient line as an organic boost. If you are already running a base nutrient program, adding Big Bloom at a reduced rate during the transition and bloom phases provides the micronutrient and biological inputs that many synthetic formulas do not include. Products like Earth Juice Hi-Brix Molasses serve a similar role as organic carbon sources and can be used alongside Big Bloom in living-soil programs.
• Garden beds and container plants. Big Bloom is not limited to controlled-environment horticulture. It is suitable for outdoor and greenhouse gardens, raised beds, and container plantings where growers want to add organic fertility without the odor and handling challenges of dry guano or raw castings.
• Seed germination support. The label notes seed formation support, and growers sometimes apply a dilute Big Bloom solution during seed starting and early transplant establishment to deliver trace minerals before a full base nutrient program begins.

FoxFarm Big Bloom vs Similar Bloom Additives

Big Bloom occupies a distinct position among bloom additives because of its organic-only ingredient list. Most bloom boosters available to hydroponic and indoor growers are fully synthetic — they deliver chelated phosphorus and potassium salts at higher concentrations but contain no biological inputs. Big Bloom trades higher NPK numbers for the microbial and trace-mineral benefits that come with bat guano and earthworm castings.

Growers choosing between Big Bloom and a synthetic phosphorus booster are essentially choosing between two different approaches. Synthetic bloom additives typically produce a faster, more measurable EC response and are more predictable in recirculating hydroponic systems where microbial populations are not wanted. Big Bloom is better suited to organic soil programs, living-soil beds, and drain-to-waste setups where biological activity is part of the growing strategy.

Within the FoxFarm line, Big Bloom is commonly used alongside Grow Big and Tiger Bloom as part of a three-way soil feed program. On its own as a standalone additive, it is closer in intent to products like Advanced Nutrients Tarantula (which also targets root-zone biology) than to a concentrated synthetic PK booster.

For growers who want a broader root-stimulation and microbial inoculant approach, Heavy 16 Roots is another option in the same nutrient and additives category, though it addresses root-zone health from a different formulation angle.

Compatibility

Big Bloom is formulated for soil and soilless growing media that support biological activity. The following notes apply to common growing environments:

• Soil and amended coco coir: Big Bloom is well-matched to soil-based systems and amended coco coir where beneficial microbes can process organic inputs. It performs as intended in these media.
• Living-soil beds and raised beds: The bat guano and earthworm castings in Big Bloom integrate naturally into living-soil systems, adding fertility without disrupting beneficial fungal and bacterial populations.
• Drain-to-waste hydroponic setups: Big Bloom can be used in drain-to-waste configurations (rockwool, perlite, coco) where the organic matter does not accumulate in a recirculating reservoir.
• Recirculating hydroponic systems: Use with caution. Organic-based liquid fertilizers can introduce particulates and organic matter that may cloud reservoir water, affect pH stability, and encourage unwanted microbial growth in recirculating systems. If using Big Bloom in a recirculating system, maintain good aeration and monitor the reservoir closely.
• pH range: Like most organic-based fertilizers, Big Bloom is best applied at a pH of 6.0–7.0 for soil applications. For soilless or hydroponic drain-to-waste, target 5.8–6.3 at the feed solution. Always pH-adjust your feed water after adding nutrients.
• Compatible nutrient lines: Big Bloom is designed to be used as part of the FoxFarm feeding program (alongside Grow Big and Tiger Bloom), but it can also supplement other nutrient lines as an organic additive. Check for precipitation or unusual color changes when combining with concentrated synthetic nutrient solutions before committing to a full reservoir mix.

Dosing Guidelines for FoxFarm Big Bloom

The following dosing guidance is based on the product’s stated use as a liquid concentrate for all growth stages. Because this is a nutrient-category product, dosing steps follow the standard nutrient supplement workflow. Specific dose rates per gallon are published on the FoxFarm feeding schedule, which is available on the FoxFarm / Hydrofarm website.

1. Shake the bottle thoroughly before each use. Organic concentrates can settle between uses, so mixing is important for consistent nutrient delivery.
2. Measure the dose per the FoxFarm feed chart. Big Bloom is typically applied at rates ranging from 2 teaspoons per gallon (during early growth) up to higher rates during peak bloom. Consult the current FoxFarm soil or hydro feeding schedule for the rate appropriate to your growth stage and medium.
3. Add concentrate to pH-adjusted water. Start with clean water at the appropriate base pH for your medium (6.0–7.0 for soil; 5.8–6.3 for soilless). Add Big Bloom to the water — not water to concentrate — and stir or agitate to dissolve.
4. Add other nutrients in the recommended order. If combining Big Bloom with other fertilizers in the same feeding solution, add each component separately and mix between additions. This reduces the risk of nutrient lockout from precipitation.
5. Check EC and pH of the final solution before applying. The relatively low NPK values in Big Bloom mean it adds minimal EC on its own, so it typically does not push EC out of range when combined with a base nutrient program. Verify pH is within target range after all additions.
6. Apply to the root zone or as a soil drench. Water your plants as normal with the prepared feed solution. For container plants, apply until you see 10–15% runoff to prevent salt accumulation over time.
7. Adjust frequency and rate based on plant response. Organic nutrients interact with the growing medium differently than synthetic salts. Monitor leaf color and overall plant vigor, and adjust dose accordingly. Because Big Bloom can be used at all stages, it can remain in the feed program from early vegetative growth through the final weeks before harvest.

Sources & Further Reading