What Does "Micron" Actually Mean?
A micron (µm) is one millionth of a metre — about 1/100th the width of a human hair. In bubble hash extraction, the micron rating of your bag refers to the size of the openings in the mesh screen. Material smaller than that opening passes through; material larger is retained by the bag.
Cannabis trichome heads range from approximately 25 to 150 microns in diameter, with most mature heads falling between 70 and 120 microns. This is why the 73–90 micron range is considered the "sweet spot" for bubble hash collection — it captures most mature trichome heads while letting fine contaminants and very small immature heads pass through into lower-value collections.
Your set of micron bags acts as a series of filters, each capturing a different fraction of the material from your wash water. Used correctly, a good bag set grades your hash automatically, separating full-melt-quality material from pressing-grade and cooking-grade fractions in a single run.
Each Micron Size Explained
The 220 micron bag is always at the top of your stack — it's where the plant material goes when you pour in your agitated ice water. This bag catches whole fan leaves, large leaf fragments, unbroken plant material, and any large debris. You throw away or compost what's collected in the 220 micron bag — it's not hash.
Role: Pre-filter only. You're collecting plant material here, not trichomes. In some setups, the 220 micron is called the "work bag" and is used to contain the cannabis during agitation — the plant material stays inside while trichomes wash out into the bucket below.
Do you need it? Yes, in every setup. Without a coarse filter at the top, plant material clogs your finer bags and contaminates your hash collections.
The 160 micron bag catches large trichome stalks, plant cell fragments, and oversized material that passed through the 220. What collects here is typically a mix of broken plant material and larger trichome structures — not clean, not particularly potent, and not really worth collecting in most setups.
Role: Secondary filtration. Some growers include a 160 micron bag in their stack as a buffer layer; others skip it. If you do collect from the 160, combine it with your other low-grade material for pressing or edibles.
Do you need it? Optional. Most home growers skip the 160 micron and go directly from 220 to 120. It adds granularity to your grading without significantly improving your best-quality collections.
The 120 micron bag catches larger trichome heads mixed with smaller plant fragments that made it past the 160 (or 220). This is genuine hash, but not clean enough for direct dabbing in most cases. It's a workhorse collection bag — decent yield, 2–3 star quality, excellent for pressing into rosin.
What you get: An amber-to-brown colored hash, somewhat wet and sticky when fresh. After drying, it crumbles reasonably well. Flavour is present but muted compared to finer bags. Strong effect when pressed into rosin or used in edibles.
Yield: Often the highest-yielding bag in the stack after the work/220 bag, because it catches everything the finer bags don't. Don't confuse high yield with high quality — this material is valuable, just not premium.
The 73 micron bag is the most coveted collection in a bubble hash run. This is where your full melt hash lives. The 73 micron opening is sized almost perfectly for mature cannabis trichome heads — large enough for the heads to collect efficiently, small enough to reject most plant material that escaped through coarser bags.
What you get: White to off-white hash when fresh (darker after drying). Under a loupe or microscope, you can see intact trichome heads. Dried properly, it has a powdery, sandy consistency. When dabbed, quality 73 micron hash bubbles and melts completely — this is the definition of full melt.
Yield: Lower than coarser bags — expect 0.5–2% of starting flower weight in excellent runs. Don't be discouraged by the small amount. A gram of 5-star full melt hash from your 73 micron bag is worth more, on a quality basis, than 5 grams of 2-star material from your 120 micron bag.
Tip: Collect your 73 micron pulls separately, label by wash number (W1, W2, W3), and grade them independently. First wash 73 micron material is almost always your best.
The 90 micron bag complements the 73 micron collection by catching the slightly larger mature trichome heads that didn't fit through the 73 micron mesh. Quality is very close to the 73 micron collection — many growers combine their 73 and 90 micron yields.
When to use both 73u and 90u: If you're targeting maximum dab-quality yield, using both gives you more full melt hash per run. If your goal is maximum purity, using only the 73 micron bag keeps your best material cleanest.
The 45 micron bag catches small trichome heads that passed through the 73 micron mesh. These are typically immature heads, slightly smaller heads from certain genetics, or fragments of larger heads broken during agitation. Quality is good — often 3–4 star — and this material is excellent for pressing.
Common use: Many growers combine their 45 micron collection with their 73 micron collection for pressing runs, keeping only their cleanest 73 micron material separate for direct dabbing.
At the bottom of your bag stack, the 25 micron bag catches the finest particles — trichome stalk fragments, very small head fragments, dissolved plant material, and fine debris. This is typically your lowest-quality hash fraction, though still usable. Appearance is often greenish or very dark compared to upper bags.
Role: More of a filter than a collection bag. What you get here is worth processing (press it or use it in edibles) but keep it completely separate from your finer collections. Some growers skip the 25 micron altogether and let this fraction go down the drain (not recommended — it contains real cannabinoids).
Standard Bag Stack Configurations
| Setup | Bags (Bottom to Top) | Best For |
|---|---|---|
| Minimal (3-bag) | 25u / 73u / 220u | Beginners; quick runs; small batches |
| Standard (5-bag) | 25u / 45u / 73u / 120u / 220u | Home growers wanting graded output |
| Full (7-bag) | 25u / 45u / 73u / 90u / 120u / 160u / 220u | Maximum grading; connoisseur production |
| Production (4-bag) | 25u / 73u / 120u / 220u | Efficiency-focused; separates dab vs press material |
For most Canadian home growers starting out, the standard 5-bag set gives the best balance of information (you can see how your wash distributed across bags) and simplicity. Once you understand your genetics and technique, you can simplify to a 3–4 bag setup focused on your target quality tier.
Where to Buy Micron Bags in Canada
Bubble hash bags are widely available in Canada from cannabis equipment retailers and online shops. Quality varies significantly:
- Bruteless Bubble Bags: High-quality Canadian brand. Screen mesh is consistent and durable. 5-gallon sets ~$80–120 CAD. Read our Bruteless review.
- Bubble Man (Original Bubble Bags): The original brand. Available through BC-based distributors. Premium pricing (~$120–160 for a full set) but exceptional quality.
- Amazon Canada: Generic sets from $25–60 CAD. Variable quality — screen count matters more than price. Check for even weave and no visible defects.
- Local grow shops: Most cannabis grow shops in BC, Ontario, Alberta, and Quebec stock at least one or two bag brands. Ask about screen specifications — not all bags labeled "73 micron" are precisely calibrated.
Cleaning and Maintaining Your Bags
Micron bags are reusable if properly maintained. After each wash:
- Rinse bags immediately with cold water — never let hash dry inside the bag
- Turn bags inside out and rinse the mesh from both sides
- Inspect mesh for clogging, tears, or holes under bright light
- Hang to dry completely before storage — damp bags mildew quickly
- Never wash in a hot washing machine — heat can warp or damage the mesh
- For deep cleaning: soak in cold water with a small amount of unscented dish soap, then rinse thoroughly
With proper care, quality bubble bags last dozens of runs. A torn or clogged bag defeats the purpose — inspect regularly and replace when the mesh is damaged.