FoxFarm Grow Big Hydroponic Fertilizer 3-2-6 | 32oz - Concentrate

Hydroponic Vegetative Fertilizer with Earthworm Castings and Kelp, 32oz

Soil-formulated fertilizers don't always translate cleanly to a recirculating hydroponic reservoir, which is why FoxFarm makes Grow Big Hydroponic as a separate 3-2-6 formula rather than adapting the soil version. Earthworm castings and kelp bring organic-derived inputs into a reservoir-friendly liquid, alongside the essential micronutrients a soilless system depends on.

The 32oz size lets hydroponic growers try Grow Big Hydroponic without committing to a larger volume.

Key Features & Benefits

• 3-2-6 NPK ratio — a hydroponic-specific balance, distinct from the soil-formulated Grow Big's 6-4-4.
• Earthworm castings and kelp — add organic-derived inputs uncommon in straight hydroponic nutrient lines.
• Essential micronutrients — supports healthy development in recirculating systems.
• Built for reservoirs, drip lines, and NFT systems — mixes cleanly into water-based delivery rather than requiring a soil drench.

Who Should Use Grow Big Hydroponic

Hydroponic and soilless growers in the vegetative stage who want an organic-derived input in their reservoir, rather than a straight mineral-salt nutrient line, are the fit for Grow Big Hydroponic.

About Fox Farms

FoxFarm builds Grow Big Hydroponic as a reservoir-specific counterpart to its soil-formulated Grow Big, part of the same Humboldt County, California nutrient lineup dating to 1984.

Frequently Asked Questions

How is Grow Big Hydroponic different from the regular Grow Big?

It carries a distinct 3-2-6 NPK ratio built for soilless and hydroponic systems, versus the soil-formulated Grow Big's 6-4-4. It also adds earthworm castings and kelp, which the soil version doesn't include.

What do the earthworm castings and kelp add to a hydroponic reservoir?

They bring organic-derived inputs into a system that otherwise runs on mineral nutrient salts. Some growers use that combination specifically to diversify their reservoir's nutrient sources beyond a straight salt-based line.

What pH and EC should I target when running Grow Big Hydroponic?

Follow the FoxFarm Hydroponic Feed Schedule for exact figures. Most hydroponic nutrient solutions run between roughly 5.5 and 6.5 pH for good nutrient uptake, and that general range applies here too.

Can I use Grow Big Hydroponic in a soil planting instead?

It's formulated specifically for hydroponic and soilless use. For soil, FoxFarm's regular Grow Big 6-4-4 is the matched product, since the two formulas aren't interchangeable.

What systems does this work in?

It's built for reservoirs, drip lines, and NFT systems, mixing cleanly into water-based delivery rather than needing a soil drench. That makes it a fit for most recirculating and drain-to-waste hydroponic setups.