Growth Science Base A – Gal

Growth Science Base A (5.5-0-0) is the nitrogen and calcium half of a streamlined two-part base nutrient system designed for growers who want efficient, complete feeding across every growth stage — from rooted clones and seedlings through late bloom — in soil, coco coir, or any hydroponic medium.

Growth Science Base A Specifications

Growth Science Base A is a liquid concentrate formulated to deliver nitrogen, calcium, and chelated micronutrients to the root zone across every stage of plant development. It carries an NPK of 5.5-0-0 and is the first part added to the reservoir in the Growth Science two-part feeding program. The product ships in a 1-gallon (128 fl oz) HDPE bottle and is compatible with fertilizer injectors, making it well-suited for commercial operations and scaled gardens alike.

Specification	Value
NPK Analysis	5.5-0-0
Primary Nutrients	Nitrogen (N), Calcium (Ca), Chelated Micronutrients
Size / Volume	1 gallon (128 fl oz) liquid concentrate
Weight	11.4993 lb
Form	Liquid concentrate
Compatible Media	Soil, coco coir, all hydroponic mediums
Fertilizer Injector Compatible	Yes
Growth Stages	All stages: rooted clones/seedlings through late bloom
Mixing Order	Add first (unless using silica; add silica first, then Base A)
pH Target — Hydro/Coco	5.7–6.2
pH Target — Soil	6.0–6.5
Partner Product	Growth Science Base B (NPK 0-6-4)
Available Sizes	Quart, 1 gal, 2.5 gal, 6 gal, 55 gal drum, 275 gal tote
Brand	Growth Science Nutrients (distributed by Hydrofarm)
SKU	GSCBAG

Why Choose Growth Science Base A

Growth Science was built around the goal of providing scientifically designed products that optimize plant growth at all stages of development at a reasonable cost. Base A reflects that philosophy directly by consolidating the nitrogen, calcium, and chelated micronutrient requirements of a plant into a single bottle that works from the first week of vegetative growth through the final days of bloom. Rather than requiring growers to purchase separate micronutrient packages, separate calcium products, or stage-specific nitrogen formulas, Base A handles all of these roles in one concentrate.

• Two-part simplicity with full nitrogen and micronutrient coverage. Base A (5.5-0-0) pairs with Growth Science Base B (0-6-4) to deliver a complete base nutrient profile from just two bottles. Compared to three-part systems that require separate grow, micro, and bloom bottles — each with stage-specific ratios — this approach reduces the number of measuring and mixing steps per feeding and lowers the chance of formula errors.
• Nitrogen delivered alongside calcium and chelated micronutrients. Base A’s 5.5-0-0 formulation is not simply a nitrogen source; it provides calcium and chelated micronutrients in the same bottle. Chelated micronutrients remain plant-available across a wider pH range than non-chelated forms, which is particularly valuable in hydroponic systems where pH fluctuations can temporarily lock out certain trace elements.
• Fertilizer injector compatible. The concentrate is formulated for use with standard fertilizer injectors, which matters for commercial greenhouse operations, large-scale indoor grows, and any facility running automated irrigation. Many retail-grade nutrients are not injector-safe due to precipitation risk at high concentration.
• Single-formula across all growth stages. The same Base A bottle is used from rooted clone through late bloom; only the dose rate changes (3 ml/gal at clone/seedling, up to 7 ml/gal during vegetative and bloom stages). This reduces inventory complexity for both home growers and commercial operations that want to minimize SKU count.
• Distributed by Hydrofarm, a long-established controlled-environment agriculture distributor. Hydrofarm has operated since 1977 and provides supply chain reliability and consistent product availability across retail and wholesale channels, which matters for growers who depend on uninterrupted supply for multi-cycle production.

Best Uses for Growth Science Base A

Base A is a broadly applicable base nutrient that performs across a wide range of growing styles, but the following use cases represent where growers get the most value out of its nitrogen-calcium-micronutrient formulation and injector compatibility.

• Hydroponic reservoirs (DWC, ebb-and-flow, NFT, drip). The liquid concentrate mixes cleanly into reservoir water. Add Base A first at the recommended ml/gal rate for the current growth stage, then add Base B and any other supplements. Maintaining the 1:1 ratio with Base B through vegetative and transition stages provides a balanced nitrogen-to-phosphorus profile that supports root development and canopy growth simultaneously.
• Coco coir grows. Coco coir is inherently low in calcium and can cause calcium deficiency if feeds are not supplemented from the start. Base A’s calcium content makes it particularly well matched to coco coir cultivation, where calcium and magnesium (provided by Base B) must both be supplied externally throughout the entire grow cycle. Target a pH of 5.7–6.2 in coco for optimal calcium uptake.
• Soil grows from seedling through late bloom. In soil, nitrogen and calcium are both essential from the first feeding. Base A’s 5.5-0-0 formulation provides nitrogen in a plant-available form without the high phosphorus load that can cause early-stage soil pH issues. Targeting a soil pH of 6.0–6.5 keeps calcium mobile in the soil profile and allows micronutrients to remain accessible to feeder roots.
• Commercial operations with fertilizer injectors. The injector compatibility of Base A makes it practical for large-scale indoor grows and greenhouse facilities where hand-mixing individual reservoir batches is not feasible. The concentrate can be proportioned directly through injection systems, simplifying nutrient delivery for large bench or container operations.
• Growers building a Growth Science nutrient stack. Base A anchors the nitrogen and micronutrient side of the two-part system. From there, growers can layer in Solid Start (kelp-based veg booster) during vegetative growth and Rock Solid (bloom booster) during flowering to provide additional targeted nutrition without switching base products. For growers interested in beneficial root microorganisms, products such as Advanced Nutrients Tarantula or Earth Juice Hi-Brix Molasses can be used alongside Base A in compatible growing programs to support microbial activity in the root zone.
• Multi-stage programs needing a single SKU. Because the dose rate simply adjusts by stage rather than requiring a product change between vegetative and bloom phases, Base A is well suited to operations that want to minimize SKU count while maintaining stage-appropriate nutrient delivery.

Growth Science Base A vs General Hydroponics Flora Series

The General Hydroponics Flora Series is the most widely referenced three-part base nutrient system in indoor growing. It consists of FloraMicro (which provides nitrogen, calcium, and micronutrients), FloraGro (which adds additional nitrogen and potassium for vegetative growth), and FloraBloom (which shifts the formula toward phosphorus and potassium for the flowering stage). The system has a large body of published feed charts, a broad third-party calculator ecosystem, and extensive documentation built up over decades of use by hobbyists and commercial growers alike.

However, the Flora Series requires growers to measure, mix, and adjust three separate concentrates per feeding session. Published feed charts call for different ratios of all three parts at different growth stages — creating meaningful complexity for anyone managing multiple plant varieties, reservoir sizes, or grow rooms simultaneously. During the shift from vegetative to bloom, for example, FloraGro is reduced while FloraBloom is increased and FloraMicro stays roughly constant, meaning growers must track three separate input rates and update them across multiple stages.

Growth Science Base A and Base B reduce that complexity to two inputs. During vegetative growth, Base A and Base B are used at equal rates. During bloom, Base B is increased relative to Base A while Base A holds steady at 7 ml/gal, which is accomplished by changing a single number in the feed chart rather than adjusting three separate inputs simultaneously. For operations running fertilizer injectors, the two-part architecture also simplifies injector station configuration: two injector heads instead of three or more, reducing equipment cost and calibration complexity. The Flora Series retains an advantage in the depth of third-party documentation and community familiarity. Growers who are already experienced with the Flora Series and comfortable with the three-part approach do not necessarily gain efficiency by switching. For growers starting fresh, scaling to commercial infrastructure, or looking to reduce mixing complexity, the two-part Growth Science system offers a tangible operational simplification.

Compatibility & Operating Range

Growth Science Base A is compatible with all common growing media including soil, coco coir, perlite, rockwool, clay pebbles (LECA), and all standard hydroponic systems (deep water culture, ebb-and-flow, nutrient film technique, aeroponics, and drip irrigation). The concentrate is suitable for use through standard fertilizer injectors, making it appropriate for professional greenhouse applications and commercial indoor growing facilities.

pH target range: For hydroponic systems and coco coir, target a reservoir or solution pH of 5.7–6.2 after adding all nutrients. For soil, a slightly higher pH of 6.0–6.5 is recommended. Base A should be added to water before checking final pH. Always test and adjust pH after all nutrients have been mixed — not before.

Runoff management: Allow 10–25% runoff with each irrigation event for best results. This practice flushes accumulated salts from the root zone and prevents buildup that can lock out calcium and micronutrients over time. In closed hydroponic systems, change the reservoir periodically or flush with plain pH-adjusted water if EC climbs significantly above the input level.

EC / TDS considerations: Base A contributes to the overall EC of your nutrient solution. At typical vegetative rates of 7 ml/gal for both Base A and Base B, combined EC will vary depending on your starting water quality (RO vs tap). Always check EC with a calibrated meter before feeding. Growers using reverse osmosis water will start from a near-zero baseline and can generally follow published rates as written. Growers using tap water with meaningful baseline EC (above 0.3 mS/cm) should reduce nutrient dose or flush more frequently to prevent salt accumulation in the root zone.

Mixing order: Base A should be added to your reservoir or mixing water first, unless you are also using a silica supplement such as Growth Science Strength (0-0-1). If silica is part of your program, add silica first, then Base A, then Base B, then any other supplements. Never mix Base A and Base B concentrates together before diluting in water; high-concentration mixing of calcium with phosphorus and sulfur ions can cause precipitation and reduce nutrient availability.

Companion products within the Growth Science Nutrients ecosystem:

• Base B (0-6-4) — phosphorus, potassium, magnesium, and sulfur; the required companion part added after Base A
• Solid Start (2-0-6) — cold-pressed kelp veg booster; used alongside Base A during vegetative growth
• Rock Solid (0-4-4.5) — bloom booster; used alongside Base B during peak flowering for additional P/K
• Strength (0-0-1) — silica supplement; compatible across all stages; add before Base A if used

Base A is not known to be incompatible with standard pH adjusters (pH up/down), beneficial microorganism products, or silica supplements. As with any nutrient program, add concentrates individually to moving water rather than combining them together before diluting.

Dosing Guidelines

Growth Science publishes a straightforward six-stage feeding chart for Base A and Base B. Base A holds a relatively stable dose rate across all stages (3 ml/gal at clone/seedling, ramping up to 7 ml/gal and holding there from aggressive vegetative through late bloom), while Base B doubles in the bloom and late bloom stages to meet the increased phosphorus and potassium demand of flowering plants. This architecture means that Base A’s contribution of nitrogen, calcium, and micronutrients remains consistent throughout the grow cycle — the plant’s need for these nutrients does not drop dramatically during bloom, unlike phosphorus and potassium which surge during the reproductive phase. All rates below are per gallon of water.

Growth Stage	Base A (ml/gal)	Base B (ml/gal)
Rooted Clones / Seedlings	3	3
Mild Vegetative	6	6
Aggressive Vegetative	7	7
Transition	7	7
Bloom	7	14
Late Bloom	7	14

Notes on applying the feeding chart:

• Start at the lower end of the range when introducing a new strain or working with plants that have not yet developed a full root system. The 3 ml/gal clone and seedling rate provides essential nitrogen, calcium, and micronutrients without overwhelming undeveloped feeder roots that are sensitive to high salt concentrations.
• The ramp from 3 to 6 to 7 ml/gal during early, mid, and late vegetative growth allows nitrogen delivery to scale with canopy expansion. As the plant adds leaf mass and new shoot tips, its nitrogen demand increases proportionally. The 7 ml/gal rate during aggressive vegetative growth and transition reflects peak nitrogen demand before the plant commits its resources to flowering.
• Base A holds at 7 ml/gal through bloom and late bloom while Base B doubles from 7 to 14 ml/gal. This is the defining feature of the two-part system: nitrogen and calcium demand during bloom remains meaningful (plants still need nitrogen to support stem elongation, leaf function, and enzyme activity during the flowering period), but it does not increase at the same rate as phosphorus and potassium demand. Rather than dropping Base A entirely during bloom — as some three-part systems do by reducing the “Grow” component — the Growth Science chart holds Base A steady while scaling Base B.
• Monitor runoff EC. At the 7 ml/gal Base A rate combined with 14 ml/gal Base B during bloom, the combined salt load to the root zone is significant. In soil and coco, test runoff EC at least once weekly. In closed-loop hydroponic systems, check reservoir EC before each top-off. If runoff EC exceeds input EC by more than 0.5–1.0 mS/cm consistently, reduce dose rate or introduce a plain-water flush day.
• Adjust for water quality. Growers using RO water start from a near-zero baseline and can generally follow the published chart. Growers using tap water with notable baseline EC should reduce nutrient dose slightly and monitor plant response, particularly for signs of tip burn or marginal leaf burn that can indicate salt overload.
• Shake well before use. As with most liquid nutrient concentrates, settling can occur during storage. Shake or swirl the bottle thoroughly before measuring each dose to ensure uniform distribution of all nutrients throughout the concentrate.

A 1-gallon bottle of Base A contains 3,785 ml of concentrate. At the average application rate across all stages (approximately 6.3 ml/gal weighted across the six-stage chart), one gallon of concentrate yields roughly 600 gallon-equivalent feedings. At the peak bloom rate of 7 ml/gal, one gallon makes approximately 541 feedings of one gallon each. For growers operating large reservoirs or running multiple reservoirs simultaneously, the 2.5-gallon, 6-gallon, and drum sizes provide meaningful cost and handling advantages over repeated gallon purchases.

How to Set Up Growth Science Base A

The following steps apply to any growing medium. For reservoir-based hydroponic systems, “feeding water” refers to the reservoir; for soil and coco coir, it refers to the irrigation water prepared for each watering event. Always use dedicated measuring syringes or cups for each concentrate and rinse thoroughly between uses to prevent cross-contamination.

1. Gather your equipment. You will need a calibrated syringe or measuring cup, a pH meter, an EC/TDS meter, a mixing container (or reservoir), and pH adjustment solution (pH up/down). Use separate syringes for Base A and Base B to avoid concentrate cross-contamination that can cause precipitation.
2. Start with clean water. Fill your reservoir or mixing container with water at your target temperature (ideally 65–72°F / 18–22°C). If using RO water, verify starting EC is below 0.1 mS/cm. If using tap water, note the baseline EC before adding any nutrients so you can account for it in your final EC target.
3. Add silica first (if applicable). If your program includes a silica supplement such as Growth Science Strength or another silica product, add silica to the water and stir before adding Base A. Silica requires a higher pH to remain stable, so it must be diluted and dispersed before the nutrient solution is acidified by the other components.
4. Shake the Base A concentrate. Shake the bottle well before measuring. Pour concentrate into the bottle cap or a separate measuring vessel before adding to water — do not pour directly from bottle to bottle to avoid measuring errors and cross-contamination of the concentrate stock.
5. Add Base A to water and stir. Add Base A at the recommended ml/gal rate for the current growth stage (see feeding chart above) and stir thoroughly. Allowing Base A to dilute fully before adding Base B reduces the risk of localized precipitation at the point where concentrated solutions meet.
6. Add Base B separately and stir. Measure Base B at its stage-appropriate rate, add to the mixing water, and stir again. Never combine Base A and Base B concentrates together before diluting; the calcium in Base A can react with the phosphate and sulfate in Base B at high concentration and form insoluble precipitates that reduce nutrient availability.
7. Add any supplemental products. If using Solid Start, Rock Solid, or other supplements, add them after both base parts have been stirred in. Follow each supplement’s recommended dose rate and stir thoroughly between additions.
8. Check and adjust pH. After all nutrients are mixed, test pH with a calibrated meter. Adjust to 5.7–6.2 for hydroponic and coco systems, or 6.0–6.5 for soil. Add pH up or pH down in small increments, stirring between additions, until the target range is achieved. Final pH should be verified after every addition.
9. Verify EC. Check EC against your target range for the growth stage. If EC is higher than desired, dilute with additional plain water and recheck. If EC is lower than expected, verify that concentrates were measured accurately and that stir/mix time was sufficient.
10. Feed plants or fill reservoir. Deliver the prepared solution to your plants immediately or use it within 24–48 hours. Prepared nutrient solution should not be stored for extended periods, especially in aerated reservoirs where microbial activity and pH drift can degrade solution quality over time.
11. Monitor and adjust over time. During the first one to two weeks with a new feeding program, observe leaf color, tip burn (a sign of over-fertilization or high EC), or interveinal chlorosis (a possible sign of micronutrient deficiency or pH lockout). Dial in dosing based on plant response rather than mechanically following the chart without observation. The 10–25% runoff target provides a useful check: if runoff EC is consistently much higher than input EC, reduce dose or add a plain-water flush day.

Sources & Further Reading