Name: Stash Blend Premium Plant Additive - Microbes, Silica, & More
Brand: Stash Blend
SKU: CCSB8OZ
Price: 29.95 USD
Availability: InStock
Rating: 5.0 (4 reviews)

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Stash Blend 3lb black pouch of plant additive with beneficial bacteria, silica, and seaweed, shown with soil and a plant.

Three black, purple-tinted bags of Stash Blend premium plant additive in 8oz, 1lb, and 3lb sizes on a wooden surface.

Stash Blend plant additive infographic showing six ingredients: powders, humic acid, roots, microbes, and soluble silicon.

Infographic for Stash Blend plant additive, featuring microbial soil nutrients to maximize genetic potential and flavor.

Back of a black, stand-up pouch of Stash Blend plant additive, showing usage directions and nutrient analysis details.

Midwest Laboratories heavy metal analysis report for Stash Blend plant additive, showing safety test results.

A white plastic bucket of Stash Blend plant additive, featuring a small green plant and a pile of soil on the side.

Stash Blend Premium Plant Additive - Happy Hydro

Six inputs. One drench. A root zone that works between your feedings.

Stash Blend delivers 2-1-5 nutrition, 3.0% humic acid, four bacterial species, and four endo mycorrhizal strains in a single weekly drench. It was formulated by a nutrient chemist together with the home growers behind the From the Stash podcast, and every batch is independently tested at Midwest Laboratories for heavy metals. One powder, half a teaspoon to a teaspoon per gallon, once a week through bloom.

Heavy Metal Tested (Midwest Laboratories) pH-Neutral After Mixing Soil, Coco, and Soilless Compatible

Free shipping on orders over $49

30-day returns on all orders

Serving growers since 2006

Gallery

See Stash Blend in action

Why it's different

One formula vs. a shelf full of bottles

Multi-Product Approach

Separate bottles for microbes, silica, and NPK supplements
Mycorrhizal inoculants applied once at transplant, never refreshed
Liquid silicon sources often raise pH, require extra balancing
Dry organic nitrogen waits on soil mineralization before uptake
Batch-level heavy metal testing not always published
Complex schedule: multiple products, multiple application windows

Stash Blend

NPK, four bacteria species, four mycorrhizal strains, humic acid, and silicon in one powder
Four Glomus strains refreshed with every weekly watering
pH-neutral after mixing, no adjustment needed
100% water-soluble nitrogen, available at the moment of application
Independent heavy metal analysis at Midwest Laboratories, batch by batch
One product, 1/2 to 1 tsp per gallon, once per week from seedling through bloom

How the biology and nutrition work together in the root zone

Most additive schedules treat biology, nutrition, and structural support as separate problems on separate timelines. A mycorrhizal inoculant goes in at transplant and is never reinforced again. A silicon supplement runs on its own watering day and often needs a pH correction afterward. Beneficial bacteria products spike activity briefly, then fade as their food source depletes between applications.

Stash Blend applies all six active components together, every week, starting from the first watering. The mycorrhizal strains get reinforced with each application rather than depending on a single transplant dose to persist for months. The bacterial species have an ongoing food source in the dissolved organic carbon and nitrogen of the solution, so activity in the rhizosphere stays steadier between feedings. Delivering the biology on the same schedule as the nutrition means the microbes are active in the root zone while the nutrients are there to be worked on.

What's in it

Six things that set it apart from standard additives

100% water-soluble nitrogen: available at application, not after mineralization 2-1-5 NPK

Most dry organic additives rely on soil bacteria to break nitrogen into a plant-available form before uptake can begin. Every gram of nitrogen in Stash Blend is already water-soluble, so plants can access it at the moment of feeding rather than waiting on that conversion.

Four bacterial species with nitrogen fixation built in 1x10^8 CFU/g

Bacillus licheniformis leads at 1x10⁸ CFU/g for nutrient cycling and organic matter breakdown. Paenibacillus azotofixans is the only nitrogen-fixing species in the blend, capturing atmospheric N directly in the rhizosphere without any separate inoculant needed.

Four endo mycorrhizal strains 7 prop/g each

Glomus intraradices, mosseae, aggregatum, and etunicatum colonize the root system and extend hyphae into media the roots do not reach directly, which improves uptake of phosphorus and water across the full container volume.

3.0% humic acid for improved cation exchange and nutrient retention

Humic acid improves cation exchange capacity in the root zone, keeping the NPK from your base nutrients accessible at the root surface longer between watering events. This is particularly useful in fast-draining media like coco coir where leaching is a persistent problem.

0.5% soluble silicon for structural strength

Soluble silicon reinforces cell walls and supports plant resilience against environmental stress and disease pressure, which matters most in high-humidity rooms. It stays soluble in solution without the pH swing that many standalone silicon products introduce.

Independently heavy metal tested at Midwest Laboratories

Every batch is run through third-party heavy metal analysis at Midwest Laboratories before it ships, and the report is available on request. For a dry input built from biological and mineral sources, that independent verification is worth having.

Specs

Numbers and guaranteed analysis

NPK Ratio

2-1-5

Nitrogen Form

100% Water-Soluble

Humic Acid

3.0%

Soluble Silicon

0.5%

Beneficial Bacteria

4 species, up to 1x10⁸ CFU/g

Endo Mycorrhizae

4 strains, 7 prop/g each

Dose Rate

1/2 to 1 tsp per gallon of water

Shelf Life

2 years (cool, dry storage)

Full Ingredient Disclosure

Derived from: Corn Steep Liquor, Seaweed Extract (Ascophyllum nodosum), Potassium Hydroxide. Beneficial Bacteria: Bacillus licheniformis 1x10⁸ CFU/g, Bacillus pasteurii 1x10⁷ CFU/g, Bacillus subtilis 7x10⁶ CFU/g, Paenibacillus azotofixans 5.5x10⁶ CFU/g. Endo Mycorrhizae: Glomus intraradices, G. mosseae, G. aggregatum, G. etunicatum at 7 prop/g each.

Add it last. Drench weekly. The root zone does the rest.

1

Mix your nutrients, then add Stash Blend last

Build your nutrient solution to target EC first. Add Stash Blend last to prevent any potential precipitation with calcium or phosphate sources already in your base program.

2

Drench soil or media, once per week

Use 1/2 to 1 tsp per gallon. Start at the seedling stage and continue through week 6-8 of bloom. No pH correction is needed after adding Stash Blend to water.

3

Biology colonizes and activates in the rhizosphere

Glomus strains begin extending hyphae from root tips into surrounding media. The bacterial species activate between feedings, cycling nutrients and, in the case of Paenibacillus azotofixans, fixing atmospheric nitrogen at the root surface.

4

Run it through the full cycle if you reuse your media

If you plan to reuse your media for another run, continue Stash Blend through harvest to keep the root zone biologically active. Otherwise, week 6 to 8 of bloom is a normal stopping point.

In the bag

What every bag contains, and which size to pick

Every bag of Stash Blend includes

2-1-5 NPK from corn steep liquor, seaweed extract, and potassium hydroxide
3.0% humic acid for cation exchange and nutrient retention
0.5% soluble silicon for cell wall reinforcement
Four bacterial species: Bacillus licheniformis, B. pasteurii, B. subtilis, and Paenibacillus azotofixans
Four endo mycorrhizal strains: Glomus intraradices, mosseae, aggregatum, etunicatum
Midwest Laboratories heavy metal test documentation on file

Available sizes

8 oz ($29.95): Home growers running a small space through a cycle or two
1 lb ($49.95): Larger spaces or growers running back-to-back cycles
20 lbs ($399.00): Bulk quantity for commercial and multi-room operations

Not sure which size fits your setup? A quick call or email and we'll work it out. Call 716-217-0353 or email help@happyhydro.com.

Questions

Frequently asked questions

Can I use Stash Blend with my current nutrient line, organic or synthetic?

Yes. Stash Blend is compatible with both organic and synthetic base nutrient programs. Add it last when building your solution to prevent any interaction with calcium or phosphate sources in your base. It does not alter pH after mixing, so no extra correction step is required.

When do I start using it, and when do I stop?

Start at the seedling stage and apply once per week through week 6 to 8 of bloom. If you plan to reuse your media for another run, you can continue through harvest to keep the root zone biologically active going into the next cycle.

Does it work in coco coir or soilless media?

Yes. Stash Blend is designed for living soil, conventional potting soil, coco coir, and most soilless media. DWC is not recommended since some ingredients are not immediately soluble, though some growers use a reduced dose in DWC with reported success. For anything other than soil or coco, start at the lower end of the dose range and evaluate from there.

The powder clumped in the bag. Is it still effective?

Yes, clumping is normal for dry powders that contain organic inputs and does not reduce effectiveness. Break up any clumps before measuring and proceed as usual. To minimize clumping, keep the bag sealed and store it in a cool, dry place away from direct sunlight. Shelf life is two years under proper storage conditions.

How much does each bag actually cover?

Coverage depends on how many gallons you apply per session. The dose is 1/2 to 1 tsp per gallon, applied weekly, so multiply your weekly water volume by the number of weeks in your run to estimate the total teaspoons you need. The 8 oz bag suits a small home setup, the 1 lb bag covers larger spaces or repeat cycles, and the 20 lb size is for commercial use. Call or email us with your plant count and typical watering volume and we'll help you work it out: 716-217-0353 / help@happyhydro.com.

Does Stash Blend replace my base nutrients?

No. Stash Blend is an additive that works alongside your existing base program, not a standalone replacement. The 2-1-5 NPK does contribute to your total feed, so factor it into your overall EC. Its job is the biology and supporting inputs (mycorrhizae, bacteria, humic acid, and silicon) that a standard base nutrient does not include.

What happens if I receive a damaged or incorrect order?

If you receive a defective or damaged unit, email us a photo at help@happyhydro.com and we'll make it right immediately. For change-of-mind returns, we accept returns within 30 days for items in new, resalable condition. If you're not sure whether this product is right for your setup, call us first at 716-217-0353. We'd rather answer your questions before you order.

Why should I buy this from Happy Hydro instead of somewhere else?

Happy Hydro has been selling growing equipment since 2006. We've carried Stash Nutrients for years because the systems work great and customers who buy them leave happy. Have questions before you order? Call 716-217-0353 or email help@happyhydro.com. We're easy to reach and happy to help!

Why Buy From Happy Hydro

Happy Hydro began as a pipe dream in a garage and has grown into something built almost entirely on word of mouth and repeat customers. Rather than focusing on raising margins and obsessing over profits, we've always believed that the right combination of competitive prices, superior products, and world-class customer service speaks for itself. Our philosophy will never change: when you're happy, we're happy.

Our commitment

What you can expect from Happy Hydro

Real People, Real Growers

Our grower support team isn't a call center. They know the products because they're passionate about growing. Reach us Monday-Friday, 10 am-4 pm EST at 716-217-0353 or help@happyhydro.com, before you order or after.

Hand-Picked by Growers, for Growers

Every brand we carry was chosen by our founders because it performs. We only stock premium brands we believe in, and every item is inspected before it leaves our warehouse.

Fair Prices and Free Shipping

We work hard to keep our prices as low as manufacturers allow, and we include free shipping on orders over $49 so there are no surprises at checkout. Find a lower price anywhere and we'll match it.

Authorized for Every Brand We Carry

We're an authorized dealer for every manufacturer on our site. That means you get the full manufacturer's warranty on every purchase. No grey market, no expired stock.

30-Day Returns on Most Orders

Hard to commit to a product you haven't tried. Return most items within 30 days in original condition and we'll take care of it. Read the full policy.

Secure Shopping, Private Data

Every transaction is SSL encrypted. We don't store payment information and we will never sell your data to anyone, ever.

Volume and Commercial Pricing

If you're a commercial grower or putting together a large order, reach out before you buy. We have pricing available that we can't advertise publicly. Call 716-217-0353 or email help@happyhydro.com and we'll take care of you.

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Stash Blend Premium Plant Additive - Microbes, Silica, & More

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