Grotek Fertilizer Guide: Feeding Schedule & Tips

AZ_Growshop_Asia · July 25, 2026, 10:17am

1. What Is Grotek?

Grotek is a Canadian fertilizer brand founded in 1998 by Greenstar Plant Products. Grotek’s philosophy is to help amateur growers achieve professional results with easy-to-use, highly effective, and affordable products.

Grotek offers 4 separate feeding charts: soil, hydro, autoflower, and organic. Each chart is optimized for its respective growing method.

AZ Growshop is the official Grotek distributor in Southeast Asia.

2. Main Product Lines

2.1 Solo-Tek Grow & Bloom

Solo-Tek Grow (7-5-9): base nutrient for the veg stage, 1-part, easy to mix
Solo-Tek Bloom (3-7-8): base nutrient for the bloom stage, 1-part
Advantage: no need to mix A+B, perfect for beginners. Just 1 bottle per stage.

2.2 Monster Series — Boosters

Monster Grow Pro (NPK: 12-7-15, powder): powerful veg growth, contains kelp extract + humic acid
Monster Bloom (PK 50-30, powder): extremely potent bloom booster, used mid-to-late bloom
Bud Fuel Pro (NPK 0-0-0, liquid): plant hormones + vitamin B, stimulates stage transition
Heavy Bud Pro (NPK 1-3-4, liquid): late bloom support, supplemental K

2.3 Grotek Organics

Pro-Silicate: organic silicon, strengthens stems and leaves
Vitamax Pro: micronutrients + amino acids
Cal-Max: CalMag, especially essential for coco coir

3. General Feeding Schedule (for Soil)

Veg Stage (Weeks 1–4):

Solo-Tek Grow: 2.5–5 ml/L (start low, increase gradually)
Monster Grow Pro: 0.5–1 g/L (from week 2)
Cal-Max: 1 ml/L (if using coco or RO water)

Transition Stage (Week 5 — Pre-flower):

Reduce Solo-Tek Grow to 2.5 ml/L
Begin Solo-Tek Bloom at 2.5 ml/L
Bud Fuel Pro: 2.5 ml/L (stimulates flowering)

Bloom Stage (Weeks 6–10):

Solo-Tek Bloom: 5 ml/L
Monster Bloom: 0.1–0.2 g/L (weeks 7–9, PK booster)
Heavy Bud Pro: 2.5 ml/L (weeks 8–10)
Bud Fuel Pro: 2.5 ml/L (throughout)

Final Week (Flush):

Water with correctly pH’d water only, or use Final Flush if available
Note: Monster Bloom maximum is 0.3 g/L. Exceeding this will cause nutrient burn and lockout.

4. Featured Products & Dosage

Monster Bloom — PK 50-30 soluble powder. Grotek’s most powerful booster.

Dosage: 0.1 g/L (bloom week 4) → 0.2 g/L (bloom weeks 5–7) → stop 1 week before harvest
Use once per week, not every watering
Combine with Heavy Bud Pro to balance K and N

Cal-Max — Grotek’s CalMag, containing Ca, Mg, and supplemental N.

Dosage: 1–2 ml/L, every watering
Use throughout both veg and bloom

5. Practical Tips from AZ Growshop

Start at 50% of the recommended dose, then increase gradually based on plant response
If you see burnt leaf tips (nutrient burn), reduce EC immediately
Monster Bloom is very strong — many users overdo it. Less = better
Solo-Tek is 1-part, no need to add anything else if you’re just starting out
Measure pH after mixing: Grotek tends to push pH up, adjust down to 5.8–6.2
Add nutrients to water, NEVER pour water into concentrated nutrients

6. Common Mistakes

Using Monster Bloom too early (bloom weeks 1–2): the plant isn’t ready to absorb high PK
Forgetting Cal-Max when using coco → early Ca/Mg deficiency
Overdosing Monster Bloom → lockout of multiple micronutrients
Not reducing Grow when switching to Bloom → excess N, delayed flowering
Using the hydro chart for soil → dosage too high, root burn

References

Grotek Official Website (2026). Product pages & feeding charts. grotek.com
Grow Barato (2025). How to use the Grotek feeding charts. growbarato.net
Alchimia Web (2025). How to use Grotek feeding charts. alchimiaweb.com
AZ Growshop (2026). Distribution experience & customer support for Grotek in Thailand.

The information in this article is for educational and reference purposes only. Growing cannabis must comply with the applicable laws of your country. In the Kingdom of Thailand, comply with the Controlled Herbs Act B.E. 2568 and Ministerial Regulation B.E. 2569.