General Hydroponics Nutrients & Hydroponic Supplies
General Hydroponics (GH) has been producing plant nutrients and hydroponic supplies for over 40 years and remains one of the most widely used nutrient brands in commercial and hobby cultivation worldwide. The GH lineup covers every growing medium - deep water culture, coco coir, rockwool, soil - with formulations from simple two-part blends for beginners to precision three-part programs used by commercial operators who want tight control over nutrient ratios at every stage of plant development.
General Hydroponics FloraSeries - The Three-Part Foundation
The FloraSeries (FloraGro, FloraBloom, FloraMicro) is General Hydroponics' flagship three-part nutrient system and one of the most widely adopted nutrient programs in hydroponics. The three-bottle format allows growers to independently adjust nitrogen, phosphorus, potassium, and micronutrient ratios across vegetative growth, transition, and flowering - providing significantly more control than one- or two-part systems at a comparable price. FloraMicro contains chelated micronutrients and calcium and is the foundation of every GH feeding schedule; FloraGro drives vegetative growth; FloraBloom drives root development, flowering, and fruit production. All three are available in quarts, gallons, and larger sizes.
General Hydroponics MaxiSeries - Dry Concentrates
The MaxiSeries (MaxiGro and MaxiBloom) delivers the General Hydroponics nutrient philosophy in a dry, water-soluble concentrate format. A single bag replaces the three-bottle FloraSeries for growers who prefer simplified mixing - one scoop per gallon at the recommended rate covers the full nutrient profile for the corresponding growth stage. Dry concentrates have significantly longer shelf life than liquid formulas, take up less storage space, and cost less to ship per ounce of actual nutrients. MaxiSeries is well suited for larger operations where bulk dry nutrients reduce cost, and for growers who want a clean, simple one-component program without the three-bottle mixing routine of FloraSeries.
pH Management, CaliMagic & Supplements
General Hydroponics pH Up and pH Down are the most widely used pH adjustment products in hobbyist hydroponics. pH Down (phosphoric acid) lowers solution pH in small increments; pH Up (potassium hydroxide or potassium carbonate) raises it. Both are highly concentrated - a small amount goes a long way, and they should be added slowly with solution mixing between additions. CaliMagic is the GH calcium and magnesium supplement, formulated to correct and prevent Ca-Mg deficiencies that are common in soft water grows, coco coir, and high-EC environments. The GH supplement lineup also includes Rapid Start (rooting enhancer), Diamond Nectar (fulvic acid), Liquid KoolBloom (phosphorus-potassium bloom booster), and Dry KoolBloom (late-stage ripening).
General Hydroponics FloraSeries for Coco, Soil & Hydro
The FloraSeries works across all growing media. In deep water culture and other recirculating hydroponic systems, use the standard FloraSeries feeding chart. In coco coir, supplement with CaliMagic from the start to compensate for coco's inherent calcium and magnesium buffering. In soil, FloraSeries works as a liquid feed - use at half the recommended hydroponic rate and water in at feeding intervals. Feeding charts are available on the GH website and in the product pages here.
Browse the complete General Hydroponics collection or explore other qualified nutrient brands: Athena Nutrients, Fox Farm, and Canna. Fast shipping.
General Hydroponics FAQ
What is the difference between General Hydroponics FloraSeries and MaxiSeries?
FloraSeries is a three-part liquid nutrient system (FloraGro, FloraBloom, FloraMicro) that allows independent adjustment of nutrient ratios for each growth stage - the most flexible and widely used GH program. MaxiSeries is a simplified dry concentrate available in two formulas (MaxiGro for vegetative, MaxiBloom for flowering) - one product per stage with a single mixing step. FloraSeries gives you more control; MaxiSeries gives you simplicity and lower cost per gallon. Both cover the full macro and micronutrient profile. Most experienced growers use FloraSeries; MaxiSeries is a popular choice for growers who want a clean, straightforward program without three-bottle mixing.
How do I use General Hydroponics pH Up and pH Down?
Mix your nutrient solution first, then test pH. Add pH Down (phosphoric acid) in small increments to lower pH - a few drops per gallon at a time - mixing thoroughly between additions. Add pH Up (potassium hydroxide) to raise pH. Both are highly concentrated; start with less than you think you need. Target pH 5.5-6.5 for hydroponic grows (5.8-6.2 optimal), 6.0-7.0 for soil. After adjusting, wait 30 seconds, stir, and re-test before adding more.
Do I need CaliMagic with General Hydroponics nutrients?
It depends on your water and growing medium. In soft water (below 150 ppm baseline TDS) or when using RO water, adding CaliMagic at 1-5 ml/gallon is strongly recommended - GH base nutrients alone may not provide enough Ca-Mg to prevent deficiency in soft water. In coco coir, CaliMagic is essentially mandatory - coco has strong affinity for calcium and magnesium ions, depleting them from solution. In hard tap water or with heavily amended soils, your baseline water likely provides adequate Ca-Mg. When in doubt, start with 2 ml/gallon and adjust based on plant response.
Can I use General Hydroponics nutrients in soil?
Yes. FloraSeries and MaxiSeries work in soil as liquid feeds - use at approximately half the recommended hydroponic rate to avoid over-fertilization, as soil contains buffering capacity that hydroponics lacks. Water in the nutrient solution at feeding intervals rather than every watering. For soil grows, the simplified MaxiBloom or MaxiGro program is often preferred over the three-part FloraSeries - soil's organic matter and microbial activity provide additional nutrient buffering that makes precise three-part ratios less critical than in a sterile hydroponic environment.
What is the General Hydroponics feeding schedule?
General Hydroponics publishes feeding charts for FloraSeries, MaxiSeries, and all their other programs - broken down by growth stage (seedling, vegetative, early bloom, peak bloom, late bloom and flush). These charts are available on the General Hydroponics website and in the product description pages here on Hydrobuilder. For FloraSeries, the standard vegetative mix is approximately 2.5-5 ml/gallon of each of FloraGro, FloraBloom, and FloraMicro. Transition and bloom ratios shift the FloraSeries balance toward FloraBloom. For MaxiBloom, the standard rate is 7 grams per gallon.
