What Is the Loompas Cannabis Strain?
Loompas is a compact, indica-dominant cannabis strain that has built a quiet following among indoor growers who want dense, trichome-heavy buds without managing a towering plant. The name is a nod to the small, efficient stature of the plant — think short internodal spacing, thick lateral branching, and colas that stack hard under a well-dialed light. If you've grown something like a compact OG or a bushy Kush phenotype, Loompas will feel familiar, but it rewards growers who dial in environment and training more precisely than most.
Whether you sourced Loompas seeds from a boutique breeder or a clone from a trusted source, this guide gives you the numbers you need: environmental targets, feeding windows, training approaches, and a post-harvest protocol that protects the terpene profile this strain is known for. For a broader overview of timing your indoor run, see our guide on how long to grow cannabis indoors.
Environment Targets for Growing Loompas Indoors
Loompas responds well to tight environmental discipline. Because of its dense bud structure, airflow and humidity management are non-negotiable — skip this and you'll be cutting out botrytis pockets in week 7. Here are the numbers to run:
- Veg temperature: 22–26°C (72–78°F), lights-on. Drop to 18–20°C lights-off.
- Flower temperature: 20–24°C lights-on. A 5–8°C differential at lights-off encourages anthocyanin expression in some phenos.
- VPD veg: 0.8–1.0 kPa. Flower: 1.0–1.5 kPa. Late flower (weeks 6–8): push to 1.4–1.6 kPa to stress-reduce final stretch.
- RH: 55–65% in veg, 45–55% in flower, below 45% in the final two weeks to protect dense colas from bud rot.
- CO₂: Ambient (400 ppm) is fine for most setups. If you're running sealed rooms with supplemental CO₂, target 900–1100 ppm during the light period.
Use our Grow Schedule Planner to map environmental transitions across your full run — it'll flag when to flip humidity and dial back feeding in the final weeks automatically.
Lighting Loompas: PPFD and Spectrum
Loompas keeps a low canopy — most phenos top out at 60–80 cm in a standard 4-week veg — which makes it excellent under mid-power LED setups without worrying about hotspot burn. Target these PPFD values at the canopy:
- Seedling/early veg: 150–300 µmol/m²/s, 18/6 photoperiod
- Late veg: 400–600 µmol/m²/s, 18/6
- Early flower (weeks 1–4): 600–800 µmol/m²/s, 12/12
- Mid–late flower (weeks 5–8): 800–950 µmol/m²/s
Run full-spectrum LEDs with a red-heavy bias (660 nm) from week 3 of flower onward. This accelerates resin development on a strain that's already predisposed to heavy trichome production. Not sure how much light your space actually needs? Run the numbers with our Grow Light Calculator before you buy or adjust.
Feeding Loompas: EC, pH, and Nutrient Schedule
Loompas is a moderate feeder — don't push it like a commercial sativa. Overfeeding in weeks 3–5 of flower is the most common mistake growers make with this strain, resulting in dark clawing leaves, salt buildup, and a harsh final smoke. Of the 1,000 grow journals tracked on Grow Guide, 63% use soil as their primary medium — if that's you, the EC targets below apply to your reservoir or top-dress schedule. Coco growers should sit at the upper end of each range.
| Stage | EC (mS/cm) | pH (soil) | pH (coco) | Key nutrients |
|---|---|---|---|---|
| Seedling (days 1–21) | 0.4–0.8 | 6.2–6.5 | 5.8–6.0 | Low N, no PK boost |
| Veg (days 21–49) | 1.0–1.6 | 6.2–6.8 | 5.8–6.2 | N-dominant, cal-mag |
| Transition/stretch (wks 1–3 flower) | 1.4–1.8 | 6.2–6.8 | 5.8–6.2 | Reduce N, raise P/K |
| Peak flower (wks 4–6) | 1.6–2.0 | 6.2–6.8 | 5.8–6.2 | High P/K, terpene boosters |
| Late flower/flush (wks 7–9) | 0.4–0.8 (flush) | 6.5 | 6.0 | Plain water or light flush solution |
Yellowing leaves that start mid-canopy in week 6 or 7 are normal — that's mobile nitrogen being redirected to the buds, not a deficiency. If you're seeing interveinal chlorosis on new growth, that points to an iron or manganese lockout, usually pH-related. Use our Nutrient Deficiency Identifier to triage fast. For seedling feeding specifics, our seedling nutrient guide has the exact ratios to start with.
Training Loompas for Maximum Yield
Because Loompas stays compact, topping or fimming early is almost mandatory if you want more than one main cola working for you. Top at node 3 or 4 during veg (around day 25–28 from sprout), then let recovery happen over 5–7 days before any LST work. The plant responds well to low-stress training (LST) after topping — bend those lateral branches out at 45° and tie down to open the canopy to direct light exposure.
A light Screen of Green (ScrOG) with 5 cm net spacing suits Loompas perfectly in a 60×60 or 80×80 cm tent. Fill the screen to 70–80% before flipping to 12/12. The compact internode spacing means the screen fills fast — usually within 10–14 days once you start weaving. For a detailed comparison of topping vs. fimming for these kinds of compact strains, read our fimming vs. topping guide.
Harvesting Loompas: Reading Trichomes Correctly
Loompas typically finishes in 56–63 days of flower (8–9 weeks) under 12/12. Don't trust the breeder's stated week count alone — read the plant. At harvest readiness you want to see:
- Trichomes: 70–80% milky/cloudy, 10–20% amber. Use a 60× loupe or digital USB microscope for accuracy. More amber = heavier, more sedative effect.
- Pistils: 70–80% have darkened and curled in. This is a secondary indicator — useful for a rough read but never the sole basis for harvest.
- Calyxes: Swollen and tight, not splitting or cracking open.
Flush 7–10 days before harvest in soil, 5–7 days in coco. Run plain water at the correct pH — don't cut EC to zero abruptly in week 6 and then wonder why terpene expression falls flat. A gradual step-down from 1.6 → 0.8 → flush is cleaner. Use our Yield Calculator to estimate your wet-to-dry weight ratio before harvest day so you're not surprised by the numbers.
Drying and Curing Loompas for Full Terpene Expression
This is where most growers leave quality on the table. Loompas is a terpy strain — rush the dry and you'll lose the profile that makes it worth growing. Target a 10–14 day hang dry, not the 5–7 day speed-dry that's tempting when jars are waiting.
- Temperature: 17–19°C (63–66°F). Cooler is better — heat volatilizes monoterpenes fast.
- Humidity: 50–55% RH. Below 45% and the outer bud dries while the core stays wet, leading to uneven cure.
- Airflow: Gentle indirect circulation — a small oscillating fan pointed at the wall, not directly at the buds.
- Light: Complete darkness. UV degrades cannabinoids and terpenes measurably over a 10-day window.
When small stems snap cleanly rather than bending, buds are ready to jar. Trim at this point if you wet-trimmed at harvest, or do your dry trim now. Cure in glass mason jars at 58–62% RH (Boveda or Integra packs work well). Burp twice daily for the first week, once daily for week two, then drop to every 2–3 days. At 4 weeks the terpene profile is fully developed. At 6–8 weeks it's at peak. Track your dry and cure window precisely with our Dry & Cure Timer — it handles the burping schedule and flags when you hit each quality milestone.
Common Loompas Grow Problems and Fixes
Dense, compact strains like Loompas tend to surface a predictable set of problems. Here's how to triage the most common ones fast:
- Botrytis (bud rot) in week 6–8: Drop RH below 45%, increase airflow, and defoliate any leaves trapping moisture inside dense bud sites. Remove affected buds immediately — don't try to save a rotting cola.
- Nutrient burn (week 3–4 flower): Drop EC by 0.2–0.3 mS/cm and flush with one feed of plain pH'd water. Check runoff EC. If it's above 3.5, do a full flush.
- Stretch not stopping (week 3 flower): If internodal spacing is still widening past day 21 of flower, verify your 12/12 is truly dark — light leaks extend the stretch phase in compact indica-dom strains.
- Overwatering in soil: Loompas roots in soil need a dry-back cycle. Lift the pot — if it still has weight, wait. The plant should reach about 30–40% of post-water pot weight before the next feed.
Track all of this week by week in a grow journal — pattern recognition across cycles is what separates consistently great results from one-offs. Our guide on keeping a cannabis grow diary is worth bookmarking before your next run.
Frequently Asked Questions
How long does Loompas take to flower?
Loompas typically finishes in 56–63 days of flower (8–9 weeks) under 12/12 photoperiod. Always confirm readiness by checking trichome color under magnification rather than relying solely on day count — growing conditions can shift the window by up to a week in either direction.
What EC should I run for Loompas in coco?
In coco, run 1.0–1.6 mS/cm through veg, scaling up to 1.8–2.0 mS/cm at peak flower (weeks 4–6), then step back down to a 0.4–0.8 flush for the final 5–7 days. Keep pH at 5.8–6.2 throughout to prevent calcium and magnesium lockout.
Is Loompas a good strain for beginners?
Loompas suits intermediate growers better than absolute beginners. Its compact structure and fast flower time are forgiving, but its dense bud sites demand solid humidity management — a skill beginners typically develop after their first run. If you're newer to growing, our one-plant indoor guide builds the foundational skills you'll need first.
How do I prevent bud rot on Loompas?
Keep RH below 45% from week 5 of flower onward, run indirect airflow across all bud sites, and defoliate any fan leaves pressing against dense colas. A VPD of 1.4–1.6 kPa in late flower naturally maintains the conditions that prevent botrytis without stressing the plant.
How long should I cure Loompas for best flavor?
A minimum of 4 weeks in sealed glass jars at 58–62% RH is the baseline. Six to eight weeks is where the terpene profile fully expresses. Rush it under 3 weeks and the flavor will be grassy and flat regardless of how clean your grow was.
References
- Advanced Nutrients (2024). Cannabis Cultivation Strategies: Nutrient Ratios, Chelation, and pH Management for Optimal Yields. Discusses why cannabis-specific nutrient formulations outperform generic fertilizers, particularly around EC management and phosphorus toxicity. advancednutrients.com
- The Seed Connect (2024). Essential Effective Cannabis Cultivation Techniques. Covers drying temperature (15–21°C), humidity (45–55% RH), and curing protocols for preserving terpenes and cannabinoids. theseedconnect.com
- The Seed Connect (2024). Organic Cannabis Cultivation: Feminized Techniques. Details trichome inspection methodology for harvest timing, including the 30–60× loupe approach and cloudy-to-amber trichome ratios. theseedconnect.com
- Grow Guide Platform Data (2026). Internal grow journal analytics across 1,000 tracked grows. Documents grow medium distribution (63% soil, 15% coco coir) and feeding method preferences (55% manual feed) among active cannabis cultivators on the platform.
- Bugbee, B. (2022). Cannabis Physiology: Light, CO₂, and Yield Responses. Utah State University. Establishes PPFD thresholds for cannabis at various growth stages and the diminishing returns above 1,000 µmol/m²/s without supplemental CO₂. Referenced widely in controlled-environment agriculture research.
