House & Garden Bio 1-Component

House & Garden Bio 1-Component Soil is a single-bottle organic magnesium supplement (20-liter jug, SKU HGBOC20L) used across the full soil-based growth cycle. It lets growers raise the magnesium level of a soil mix on demand and is specifically formulated to correct soils that are heavy in lime. The formula is intentionally calcium-free so growers can adjust magnesium independently of calcium, and it is certified organic under EU regulation EEC No 2092/91.

House & Garden Bio 1-Component Specifications

The specifications below are taken from the House & Garden product page for Bio 1-Component Soil and the supplier listing for SKU HGBOC20L.

Why Choose House & Garden Bio 1-Component

The points below are drawn from the House & Garden product page and the canonical supplier description.

• Targeted magnesium control. The primary function of Bio 1-Component Soil is to let growers customize the magnesium level of their soil. Rather than buying a broad cal-mag product that adjusts calcium and magnesium together, Bio 1-Component supplies magnesium on its own (0.5% Mg). Growers who already have adequate calcium — or who are intentionally limiting it — can raise Mg without disturbing the calcium side of the equation.
• Corrective for lime-heavy soils. The product is specifically positioned for soils that are heavy in lime. Limestone-amended soils tend to have elevated calcium and high pH, which can suppress magnesium uptake even when Mg is present in the medium. Adding a focused magnesium supplement on top of a lime-heavy soil helps restore a workable Ca:Mg ratio without compounding the calcium load.
• Calcium-free by design. The formula contains no calcium. This is a deliberate choice that distinguishes Bio 1-Component from cal-mag blends and lets growers separate the two cations in their feeding program. For soil mixes that already contain dolomite or oyster shell, an additional calcium dose can create lockouts; a calcium-free magnesium additive avoids this.
• Certified organic. Bio 1-Component is certified organic under EU regulation EEC No 2092/91. For growers maintaining organic standards in their grow program, the certification places this product in the same category as other House & Garden Bio-line products that meet EU organic input criteria.
• Full-cycle compatibility. The product is dosed across the entire grow cycle, not just one stage. Application rates range from 2 mL per gallon at lower-demand intervals up to 18 mL per gallon when magnesium demand is highest. The same bottle supports vegetative and flowering use without requiring a stage-specific reformulation.
• Made by a dedicated Dutch nutrient brand. House & Garden is a Dutch nutrient line with a premium positioning and a soil-specific product family. Bio 1-Component sits within that family alongside the brand’s Soil A, Soil B, and Bio-line additives, so the product is built to integrate with the rest of the House & Garden feeding program rather than as a standalone retrofit.

Best Uses for House & Garden Bio 1-Component

Bio 1-Component Soil is categorized in Nutrients & Additives → Additives → Growth & Bloom Boosters. The following use cases reflect that placement and the product’s described function.

• Soil grows on lime-heavy media. The clearest application is a soil grow where the substrate has been amended with dolomite lime, garden lime, or similar calcium-carbonate sources, and the grower is seeing signs of magnesium suppression. Adding Bio 1-Component at the recommended rate raises plant-available Mg without adding more calcium to an already calcium-rich profile.
• Soil programs running an organic feeding regimen. Because the product is certified organic under EU EEC No 2092/91, it can be used in grow plans where the entire input list needs to qualify as organic. It pairs with the rest of the House & Garden Bio line and other organic additives in the same reservoir or watering can without breaking the organic profile.
• Coco coir and peat-based mixes that need magnesium without calcium. Some coco-based and peat-based potting mixes are pre-buffered or amended with calcium. When magnesium starts to lag mid-cycle, an Mg-only additive avoids stacking more Ca on top of an already-buffered medium. Bio 1-Component fits this niche while remaining a soil-labeled product.
• Mid-cycle correction for interveinal yellowing in older leaves. Classic magnesium-deficiency symptoms — interveinal chlorosis showing first on older leaves — can develop in soil grows even when a general nutrient program is in place. Bio 1-Component is one option for a targeted corrective dose that does not alter the calcium balance set by the base soil program.
• Companion to a House & Garden soil feeding stack. Growers running House & Garden Soil A and Soil B as their base nutrients can add Bio 1-Component as the magnesium-specific top-up where the base profile alone is not delivering enough Mg for the crop, the strain, or the medium. Because all three products come from the same brand, the formulations are designed to coexist in the same feeding chart.
• Larger soil gardens that benefit from the 20-liter pack size. The 20 L jug (51.75 lb shipping weight) is sized for commercial or large home grows where smaller bottles would require frequent reorders. Growers running multiple soil beds or large containers across a long cycle can keep a single jug on hand for the season.

House & Garden Bio 1-Component vs House & Garden Magnesium Boost

Within the House & Garden range, the closest sibling to Bio 1-Component is House & Garden Magnesium Boost — another magnesium-focused additive from the same brand. Both products target magnesium supplementation in a soil-based grow, but they sit in different lines (Bio organic line versus the standard Magnesium Boost line) and the practical differences come down to certification, composition focus, and how each fits into a broader feeding program.

The decision between the two largely comes down to whether the grow program requires a certified-organic magnesium source and whether the calcium-free composition matters in context. Bio 1-Component is the choice when an organic certification and a calcium-independent Mg dose are both required; Magnesium Boost is the more general-purpose pick when neither constraint applies.

Compatibility & Operating Range

The compatibility notes below are derived from the House & Garden product page and the canonical supplier description.

• Growing medium: Bio 1-Component is labeled for soil-based grows. It is positioned as a magnesium supplement for soil systems, with particular value in soils amended with lime or similar calcium-carbonate sources. The product is not labeled as a hydroponic nutrient base or as a stand-alone medium amendment.
• Growth stage: The recommended dose rate spans 2–18 mL per gallon depending on the stage of the cycle. That range covers vegetative through bloom use, so the same bottle is intended to remain in the feeding rotation across the full grow rather than being limited to a single phase.
• Calcium-free use case: Because the formula contains no calcium, Bio 1-Component is best suited to feeding programs where calcium is supplied separately (through the soil amendment, base feed, or a dedicated calcium product) and the grower wants to control magnesium independently. Programs that rely on a single cal-mag product for both elements may find a different product type more appropriate.
• Organic-program compatibility: The EU EEC No 2092/91 certification makes it usable in organic grow programs where the input list must qualify as certified-organic. Growers operating outside organic frameworks can still use the product, but the certification is the relevant compatibility marker for organic-only stacks.
• Brand-line integration: Bio 1-Component is designed to work alongside the rest of the House & Garden range, including the brand’s Drip Clean system-maintenance additive and the Soil A / Soil B base nutrients. Mixing across House & Garden products in the same feeding solution is a documented use pattern from the brand.
• Storage and handling: Standard liquid-concentrate handling applies. Keep the jug closed when not in use, store away from direct sunlight, and avoid freezing. Liquid mineral concentrates can precipitate or shift in composition if frozen.
• Pack size: The 20-liter jug ships at approximately 51.75 lb. Plan freight and storage accordingly; this is a commercial-scale pack size rather than a small bottle.

Dosing Guidelines

Bio 1-Component Soil is a liquid concentrate dosed in milliliters per gallon of feeding water. The dose information below is sourced from the House & Garden product page.

Choosing a dose within the range. The 2–18 mL/gal span exists because magnesium demand is not constant across a grow. Lower doses suit early growth and intervals where leaf tissue looks healthy and no deficiency signs are present. Higher doses are appropriate when interveinal yellowing appears on older leaves, when the substrate is particularly lime-heavy, or when bloom-stage Mg demand peaks. Use the House & Garden nutrient calculator and feeding chart on the brand website to dial in the dose for your specific crop and stage.

Volume reference for the 20-liter jug. 20 liters equals roughly 20,000 mL. At an average dose of 10 mL/gal, the jug provides enough concentrate for approximately 2,000 gallons of feed water; at the maximum 18 mL/gal rate, roughly 1,100 gallons. For a single soil grower running 5–10 gallons of feed per watering across multiple plants, this pack size will typically cover a full season or longer.

Verify with plant response. Magnesium dosing is best calibrated to plant response and substrate testing, not to a fixed schedule. Increase the dose gradually if older-leaf interveinal chlorosis appears; reduce the dose if leaf tips show signs of overuse. Always adjust pH of the final feed solution to the appropriate range for soil before applying.

How to Install / Setup

Bio 1-Component is a liquid nutrient additive and follows standard hydroponic supplement mixing practice. The steps below reflect normal soil-feed preparation alongside the House & Garden dosing guidance.

1. Shake the jug before use. Liquid nutrient concentrates can stratify in storage. Invert and gently agitate the 20 L jug before drawing any concentrate so the mineral and organic components are uniformly suspended.
2. Fill the watering vessel. Start with clean water at the volume you plan to apply to the soil. Use the gallon volume of your watering can, reservoir, or feed tank as the basis for measuring the dose.
3. Measure the dose for the current stage. Using a calibrated syringe or measuring cup, draw the appropriate dose within the 2–18 mL per gallon range. Start at the low end of the range when introducing the product for the first time so you can observe plant response before scaling up.
4. Add base nutrients first, then Bio 1-Component. If you are using House & Garden Soil A / Soil B or another base feed, add and mix those nutrients into the water first. Add Bio 1-Component after the base feed is in solution and stir thoroughly to integrate.
5. Add other House & Garden additives as scheduled. Follow the House & Garden feeding chart for any additional brand additives in the program. Each additive has its own dose rate and stage-specific scheduling; add them in the order recommended by the chart and stir between additions.
6. Adjust pH after mixing. Once all nutrients and additives are dissolved, measure the pH of the feed solution. Adjust to the appropriate range for soil (typically 6.0–6.8) using a pH-up or pH-down product before applying to the medium.
7. Apply to the soil. Water the soil with the mixed feed solution. For container grows, water to runoff to maintain a clean substrate; for in-ground beds, apply enough volume to reach the active root zone.
8. Observe and adjust. Watch for interveinal chlorosis on older leaves (under-dose signal) or tip damage (over-dose signal). Adjust the next feeding’s Bio 1-Component dose within the 2–18 mL/gal range based on what you see.
9. Close and store the jug. Recap the 20 L jug after each use. Store away from direct sunlight and avoid freezing temperatures. Liquid concentrates can precipitate or shift in chelation when frozen.

Sources & Further Reading