Bud Booster

Regular price$51.50

Massboost is a highly concentrated supplement containing calcium. magnesium, nitrogen and sulfur to support healthy, vigorous growth through both veg and flower. Massboost is the calmag of choice for indoor and outdoor coco, peat and soil growers in run-to-waste systems.

For cultivators running hydroponic, DWC, recirculating or fertigation systems, use APTUS’ Mineral-Calmag.

Calcium / Magnesium supplement & bud booster

Application - Root drench and foliar spray

Available Sizes

    Feed Programs

      Feeding Type and Amount

      Clones & seedlings
      1 ml per 1 gallon

      Regular feeding (vegetative)
      1 - 1.5 ml per 1 gallon

      Regular feeding (flowering)
      1 - 2 ml per 1 gallon

      Foliar spray (maintenance)
      8 ml per 1 gallon

      Foliar spray (repair)
      16 ml per 1 gallon

      Clones & seedlings
      0.25 ml per 1L

      Regular feeding (vegetative)
      0.25 – 0.33 ml per 1L

      Regular feeding (flowering)
      0.25 – 0.5 ml per 1L

      Foliar spray (maintenance)
      2 ml per 1L

      Foliar spray (repair)
      4 ml per 1L

      When mixing with any phosphorus supplements (PEAKBOOST or mineral fertilizers), be sure to allow one to mix into solution before adding the other.  

      MASSBOOST prevents calcium and magnesium deficiencies while stimulating powerful fruit set and development. Calcium and magnesium are just as important as the macro elements nitrogen (N), phosphorus (P), and potassium (K) you see on the front of every fertilizer label. BASE grow and bloom NPK fertilizers only include small amounts of calcium and magnesium, which in high intensity growing environments can quickly be consumed by your plants. MASSBOOST fixes this problem of under-supply by providing large amounts of plant available calcium and magnesium. 

      MASSBOOST is best used in soil, coco, or peat drain to waste applications. If you need a calcium & magnesium supplement for use in clean recirculating or fertigation applications, use MINERAL-CALMAG. 

      Calcium along with the silica in FASiLITOR largely comprises the structure of the plant cell wall which gives the plant it’s physical shape. An uninterrupted supply of calcium contributes to healthy flowers and leaves, strong stems and continued formation of healthy plant tissue. Calcium’s impact on plant health can be seen by preventing blossom end rot, underdeveloped flowers and a lack of necrosis on plant tissue. 

      As the plants undergo cell division forming new tissue, the increased supply of magnesium allows for continued production of chlorophyll in the leaves. Magnesium is the central element to chlorophyll which is crucial to the process of photosynthesis enabling the plant to turn sunlight into usable forms of energy.

      Highly available, 100% water soluble and leaves no residue behind. 

      Provides calcium which improves firmness and structure of fruits during the flowering phase of growth. 

      Provides magnesium which is the central element to chlorophyll allowing photosynthesis to occur.

      Provides the extra boost plants need during certain plant-development phases and other important natural bio-stimulants

      Calcium Integral structural element to plant cell walls and thus overall physical plant structure.

      Magnesium Element central to the formation of chlorophyll and thus essential for photosynthesis to occur.

      MASSBOOST is the calmag of choice for indoor and outdoor farmers growing in soil, coco or peat. 

      Used as both a root drench and or foliar feed, indoor, outdoor and greenhouse cultivators will add MASSBOOST to their foliar regime for the last week of veg and first 2 weeks of flower to increase growth and prevent calmag deficiencies in hungry cultivars.

      Massboost FAQs

      No, not unless you’re only using MASSBOOST as a foliar spray. As a root drench you only need to use either MASSBOOST or MINERAL-CALMAG, not both.

      While MASSBOOST and MINERAL-CALMAG are both calcium/magnesium additives, and are both formulated for the same stages in plant development, they are two very different products, formulated for two different styles of cultivation.

      MASSBOOST is a formula made for effectiveness in a dirt environment and excels in peat, coco coir, and soil. In these environments, MASSBOOST is incredibly effective and available to the plant. Its formulation for effectiveness in dirt environments however is what makes MASSBOOST inadequate for hydroponic, DWC, and fertigation systems.

      MINERAL-CALMAG is a 100% water-soluble mineral formula that has excellent pH stabilizing capabilities and can be left in a nutrient tank or reservoir for up to 14 days with no signs of degradation. MINERAL-CALMAG is extremely clean and will not cause salt build-up or blockage in fertigation lines, drippers, feeders or spray rings. MINERAL-CALMAG is suitable for every substrate and every method of cultivation.

      The choice of which APTUS calmag to use should be based entirely on your substrate and cultivation method.

      If you’re growing in rockwool or water, then you would use MINERAL-CALMAG. You should not use any organic fertilizers when growing with rockwool or water as a substrate.

      If your irrigation method is run-to-waste and you grow in coco, peat or soil (providing you mix fresh feed daily/bi-daily) then MASSBOOST is the preferred choice.

      If you’re running a recirculating hydroponic system, fertigation system or long multiday reservoir, then MINERAL-CALMAG is the preferred choice.

      Yes, there are a lot of outdoor soil growers that use MASSBOOST as a densifier and bulking product for their sun-grown soil crops. For this application we commended root drenching at least once per week in weeks 3 and 5 for shorter 49-63 day flowering plants, and again at week 7 for longer flowering plants.

      MASSBOOST is very effective for the quick recovery of nitrogen, calcium and or magnesium deficiencies when applied as a foliar spray through veg and early flower (note: it’s not recommended to foliar spray after week 2 of flower). Experienced Indoor and outdoor cultivators incorporate MASSBOOST into their foliar program for heavier feeders (i.e. magnesium hungry phenotypes) to prevent nitrogen, calcium and magnesium deficiencies.

      Preloading healthy plants by adding 8 - 16 ml per gallon to your foliar program for the last week of veg and first 2 weeks of flower is a great way to prevent nitrogen, calcium and magnesium deficiencies in heavy feeders.

      For best results, foliar spray with FASiLITOR, STARTBOOST and MASSBOOST in veg, and FASiLITOR, BLOOMBOOST and MASSBOOST for the first 2 weeks of flower.

      Vegetative foliar spray

      4 ml per 1 gallon

      4 ml per 1 gallon

      8 - 16 ml per 1 gallon
      MASSBOOST *optional


      Flower foliar spray

      *Note: it’s recommended to foliar spray for the first 2 weeks of flower only.

      4 ml per 1 gallon

      4 ml per 1 gallon

      8 - 16 ml per 1 gallon
      MASSBOOST *optional

      Feed Programs


      This program is the easiest, most concentrated, low cost program on the market. The pH stability is so reliable you can mix and set your reservoir on a given day and it will read exactly the same (+- 0.05) seven days later with no adjustment in between.


      This program is the absolute gold standard of quality, flavour, oil production and shelf life. This is the program for the grower looking to produce the absolute best flower they can or any extraction artist looking to increase the quality, colour and yield of their extracts.


      Access to the OG programs that include Soil PRO and Soil BASIC, as well as the Extreme Program.

      All of these are available for download.

      Faster, Healthier
      Root Development

      Thicker, Stronger

      Higher Quality
      Fruits & Flowers


      Superior Flavor Profile

      Increased Bag