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MAMMOTH Si Availability Map


Is Mammoth Si a liquid or dry product?

Mammoth Si is a liquid product. 

What is the shelf life? When does it expire after opening?

Mammoth Si shelf life is 2 years.

How do I store Mammoth Si?

Always store Mammoth Si in its original packaging. Store locked up in a dry and well-ventilated area.

How do I measure the product?

Measure small amounts of Mammoth Si with a pipette, syringe, or small measuring cup. If measuring larger amounts, use a larger measuring cup or graduated cylinder.

What is the application rate and frequency for applying Mammoth Si?

Apply 0.5 mL/Gallon, every 5-7 days (always adjust pH accordingly after mixing into reservoir).

Can I use on my seedlings/clones?

We recommend starting applications at the vegetative growth stage.

Do I add to nutrient mix? If so, when? Is the order of mixing important?

Yes and the order of mixing is important: add Mammoth Silica first, then any nutrients and pesticide products, adjust pH if necessary, and add any beneficial products (i.e. Mammoth P) as a final step.

Do I need to pH my water with the silica product?

Yes, always adjust pH after adding Mammoth Si.

How frequently should I apply Mammoth Si?

Apply Mammoth Si every 5-7 days.

What are the main benefits of running Mammoth Silica?

Plant strength and stature.

Do I use in flower and flush?

We specifically formulated this product with low nitrogen so growers can use it in the flowering stage of growth, reducing a need for two products or differing application rates.

Are there any products I shouldn’t run this with?


Is this organic/OMRI-certified?


I already use a silica product, how is this different?

Low usage (application) rate, lower nitrogen for use from vegetative through bloom growth phases – only one product is needed for any growth stage, Mammoth Si has a high mono-silicic acid percentage with 1.9%.

Can I get a sample of this new silica product?

Please visit your local retailer in states with approved registration.

Why is the monosilicic-acid (MSA) percentage not displayed on the Mammoth Silica product label?

We see many silica product labels that do not list mono-silicic acid percentage claims due to the high variability of how labs can analyze and present these claims. Mammoth uses the testing methods that California & AAPFCO use for measuring soluble silicon.

What is the difference between potassium silicate and mono-silicic acid?

Potassium silicate is a silica source (very alkaline on pH scale) and it must be converted into mono-silicic acid before it’s available for plant uptake. Mono-silicic acid is the plant-available form of silica and it’s derived from a silica source.


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