Roots Organics CalMag – 5 Gallon

Roots Organics CalMag in the 5-gallon size is the bulk pack of Roots Organics’ calcium, magnesium, and sulfur supplement. The blend is derived from Kieserite and Gypsum and is deliberately free of added nitrogen, phosphate, and potassium, which lets growers correct cal-mag deficits without disturbing the N-P-K ratios already set by their base feed. The 5-gallon size is sized for multi-room operations, fertigation tanks, and gardens that move through cal-mag in volume.

Roots Organics CalMag 5-Gallon Specifications

Roots Organics CalMag is part of the Roots Organics line of soil amendments and nutrients formulated by Aurora Innovations. The 5-gallon size is the largest stock pack and sits above the quart, gallon, and 2.5-gallon retail sizes.

Why Choose Roots Organics CalMag

Roots Organics positions CalMag as a clean cal-mag corrective rather than a hidden booster. Several design choices follow from that:

• No added N, P, or K. Many cal-mag supplements ship with a low-N kicker that quietly raises the nitrogen baseline of your feed. Roots Organics CalMag is deliberately free of added nitrogen, phosphate, and potassium so the cal-mag dose does not move the rest of your nutrient program off its intended ratios.
• Derived from Kieserite and Gypsum. Kieserite supplies magnesium and sulfur; gypsum supplies calcium and sulfur. Both are mineral inputs used widely in commercial horticulture for predictable solubility and behavior in a mix tank.
• Calcium-magnesium-sulfur in one bottle. The third element — sulfur — often gets lost in conversations about cal-mag, but it is essential to amino-acid and protein formation. Roots Organics’ use of sulfate minerals delivers sulfur as a built-in part of the cal-mag dose.
• Built around the Roots Organics line. Roots Organics recommends CalMag in combination with Buddha Grow and Buddha Bloom. The supplement is designed to slot into the same feed program without precipitate or EC conflict when dosed at label rates.
• Bulk pack economics. The 5-gallon size lowers the per-gallon cost relative to quart and gallon retail packs, and reduces re-order cadence for cultivations running heavy cal-mag through bloom.

Best Uses for Roots Organics CalMag 5-Gallon

The 5-gallon jug is sized for operations that consume cal-mag in volume:

• Multi-room cultivation. Facilities running multiple veg and flower rooms off a shared mixing station can draw cal-mag from a single 5-gallon jug across the whole canopy.
• Soft-water and reverse-osmosis programs. RO and naturally soft water arrive at the plant with very low calcium and magnesium. CalMag is dosed back in at every feed to restore the baseline before the rest of the nutrient program goes in.
• Coco coir and soilless media. Coco’s cation-exchange behavior locks up calcium and releases potassium in the first weeks of use. A consistent CalMag dose offsets that pattern across the whole grow.
• Heavy-feeding and fast-growing crops. Heavy feeders pull calcium and magnesium through the stretch and into mid-bloom. Roots Organics specifically markets CalMag for fast-growing and heavy-feeding plants.
• Roots Organics Buddha Grow and Buddha Bloom programs. When you are already feeding the Roots Organics base line, CalMag is the brand’s matched cal-mag corrective and pairs without retuning EC ratios.
• Fertigation reservoirs. Tanked nutrient solutions feeding drip or flood-and-drain systems benefit from a stable cal-mag baseline; a 5-gallon jug drops into a parent-tank workflow without constant re-stocking.

If you are running the Roots Organics base line, the matched pairs to dose alongside CalMag are Roots Organics Buddha Grow 5-Gallon for veg and Roots Organics Buddha Bloom 5-Gallon for flower.

Roots Organics CalMag 5-Gallon vs Smaller Pack Sizes

Roots Organics publishes CalMag in quart, gallon, 2.5-gallon, and 5-gallon sizes. The 5-gallon is the same product as the smaller packs; the choice between sizes is throughput, storage, and per-gallon economics, not formulation:

If your operation moves through a quart of CalMag every couple of weeks, the 5-gallon size flips the per-gallon math in your favor. For smaller grows, our Roots Organics CalMag 1-Quart and the Roots Organics CalMag 2.5-Gallon are easier to handle and store.

Compatibility & Operating Range

Roots Organics CalMag is built around a cal-mag-sulfur chemistry that mixes cleanly into most feed programs at label rates:

• Compatible nutrients: Roots Organics Buddha Grow and Buddha Bloom are the brand’s recommended pairing. CalMag also mixes with most third-party base nutrient lines when dosed first into clean water and followed by EC and pH verification.
• Water sources: reverse-osmosis, distilled, and naturally soft water benefit most. Hard water with measured cal-mag already present needs a reduced dose; verify with a water analysis or a starting-EC reading.
• Media compatibility: coco coir, peat-based mixes, soil, and hydroponic substrates. Coco growers in particular run CalMag from week one of the grow to offset the cation-exchange behavior of fresh coir.
• Application methods: hand-watered drench, drip fertigation, or flood-and-drain. Pre-mix into the nutrient solution before any pH adjustment so EC is set before final pH is targeted.
• Mixing order: add CalMag to clean water first, then base A, base B, then any additives. This sequence keeps calcium and phosphate from contacting each other at high concentration and avoids precipitate at the bottom of the mixing tank.
• Storage: store the sealed jug at room temperature out of direct sun. Re-cap tightly between uses to keep moisture and contaminants out of the headspace.
• Service life: a 5-gallon jug at a typical 2 to 5 ml-per-gallon dose runs hundreds of gallons of finished nutrient solution. For a single room moving through 200 gallons of solution per week, expect months of supply per jug.

Usage & Dosing Guidelines

Roots Organics publishes feed guidance for the line on the product label and on therootsorganics.com. The label is the authoritative source for the current dose; the patterns below describe how growers typically deploy CalMag across a grow cycle:

• Vegetative stage: dose into every feed water at the published ml-per-gallon rate. Veg is when canopy expansion and new shoot growth pull calcium hardest, so a steady cal-mag baseline avoids the tip-burn and interveinal-yellowing signatures of cal-mag deficit.
• Bloom stage: continue CalMag through stretch and into mid-bloom, when bud sites are setting and demand for calcium peaks. Roots Organics specifically lists fast-growing and heavy-feeding plants as the target use case.
• RO and soft-water programs: CalMag is run at every feed from week one of veg, since RO and distilled water do not deliver any cal-mag baseline of their own.
• Coco coir programs: dose CalMag from the first feed after transplant into fresh coco. The cation-exchange behavior of new coir absorbs calcium and releases potassium, and CalMag offsets that pattern until the coir equilibrates.
• Foliar spray: some growers spot-treat early-stage cal-mag deficits with a foliar mist at a reduced dose. Foliar is a stopgap; the underlying root-zone feed is what drives the long-term correction.
• EC management: CalMag adds a measurable EC contribution. When stacking it onto a feed program, recalculate the base-nutrient dose so total EC stays inside the target window for the crop and stage.

How to Set Up the 5-Gallon Jug

Receiving the 5-gallon jug and integrating it into a mixing-station workflow:

1. Inspect on arrival. Confirm the jug’s cap and seal are intact and there is no shipping damage. A ~52-lb jug travels well in a single carton but can take a bruise in transit.
2. Position in the mixing area. Store the jug near the mixing tank or daily decant station. Keep it out of direct sun and away from heat sources; room temperature is fine.
3. Decant into a daily-use container. A 5-gallon jug is awkward to pour against a measuring jug for every feed. Decant a quart or gallon into a smaller measuring container and refill it from the 5-gallon every few days.
4. Set up a measuring routine. Use a graduated cylinder or pump dispenser sized for the typical batch size. Pre-measure cal-mag for the batch before opening any base-nutrient bottles to avoid dose drift.
5. Dose into clean water first. Add the measured CalMag to the mixing tank before any base nutrients or additives. Stir or recirculate for a minute before the next addition.
6. Add base nutrients in sequence. Follow your base-feed manufacturer’s recommended order — typically base A, then base B, then additives. CalMag goes in before phosphate-bearing inputs to avoid precipitate.
7. Verify EC and pH. Read total EC and adjust pH to your target range after all additions are in. Recheck EC if you adjust pH significantly.
8. Log open date and consumption. Track the jug’s open date and weekly consumption so re-orders are placed before you run out; bulk-pack lead times can run a week or more.

Sources & Further Reading