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Availability:
In Stock.
Arrives
Monday, Jun 22
Size: 2.5 Pound Kit (1 lb MB, 1 lb CN, 0.5 lb ES)
Features
- MasterBlend 4-18-38 Master Kit (3 Separate Components in correct amounts)
- Contains MasterBlend 4-18-38, Calcium Nitrate 15.5-0-0, and Epsom Salt (Magnesium Sulfate)
- Used by professionals worldwide for optimum plant growth
- 100% Water Soluble for easy plant uptake
- Packed by weight in a 1/1/0.5 ratio based off the MasterBlend recipe of 12g MB, 12g, CN, and 6g ES
Description
The MasterBlend Combo Kit contains all 3 concentrated components needed. The MasterBlend recipe calls for 12g MasterBlend, 12g Calcium Nitrate, and 6g Epsom Salt to make 5 gallons of nutrient solution, where each component is mixed into the water individually. Available in quanties from 1lb to 62.5 pounds. Packed in clear bags by PowerGrow Systems (authorized MasterBlend distributor). The 2.5 Pound Kit contains: 1LB MasterBlend, 1LB Calcium Nitrate, 0.5LB Epsom Salt.
Brand: MasterBlend
Item Weight: 10 Pounds
Item Form: Powder
Liquid Volume: 5 Liters
Specific Uses For Product: Plant Growth
Brand Name: MasterBlend
Model Number: MASTERBLEND-COMBO_2.5LB-KIT
Manufacturer: MasterBlend
Unit Count: 1 Count
Part Number: AACXZSG-119
Item Weight: 10 Pounds
Liquid Volume: 5 Liters
Item Form: Powder
Specific Uses For Product: Plant Growth
Coverage: Full
Target Species: Plants
Mixing Ratio: 110.5
Frequently asked questions
If you place your order now, the estimated arrival date for this product is:
Monday, Jun 22
Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
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Top Amazon Reviews
Size: 5 Pound Kit (2 lbs MB, 2 lbs CN, 1 lb ES)
I have been using the MASTERBLEND 4-18-38 Complete Combo Kit for my hydroponics and Kratky method, and let me tell you, it's a game changer! With its 100% effectiveness, this kit has truly transformed my growing experience. The nutrient mix provided in this kit is exceptional. It has all the essential elements plants need for healthy growth, resulting in vigorous and lush greenery. The balanced ratio of 4-18-38 ensures optimal nutrient uptake, giving my plants the perfect blend of nitrogen, phosphorus, and potassium. What I love most about this kit is its versatility. Whether I'm using hydroponics or the Kratky method, the MASTERBLEND formula consistently delivers outstanding results. It's convenient to use and saves me the hassle of managing multiple nutrient solutions. The quality of the product is top-notch. The ingredients are of the highest standard, ensuring that my plants receive the best nutrition. I've seen remarkable improvements in growth, flowering, and overall plant health since I started using this kit. If you're into hydroponics or the Kratky method, the MASTERBLEND 4-18-38 Complete Combo Kit is an absolute must-have. It's a complete game changer that will take your growing to new heights. I highly recommend it for both beginners and experienced growers. Trust me, you won't be disappointed!
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Reviewed in the United States on June 14, 2023 by IamMarkyMarc
Size: 5 Pound Kit (2 lbs MB, 2 lbs CN, 1 lb ES)
A lot of YouTubers recommended this so I thought I'd give it a try. When it arrived, I was quite surprised how small the packages were, but it matched the description so that's on me. That said, a little goes a long way. I've used this in both a system with aeration and without (Kratky method) and it worked perfectly in both cases. Here's what I've grown with it: - Basil indoors with natural light - Basil indoors with artificial light - 2 kinds of Lettuce indoors with artificial lights - Spinach indoors with artificial lights - 2 types of tomatoes outdoors with natural light. The Plant growth with this fertilizer and the hydroponic method was far superior to similar plants planted in dirt. The plants that had aeration did better the ones in using the Kratky method. I don't think I'll try tomatoes again simply because they take so much solution throughout the year vs. the ones I planted in self watering soil containers. Overall, 5 stars. Works as well as the YouTubers claimed it would and lasts a long time.
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Reviewed in the United States on December 19, 2025 by Sam E
Size: 5 Pound Kit (2 lbs MB, 2 lbs CN, 1 lb ES)
It looks as though all of my indoor and outdoor plants are loving these fertilizers.
Reviewed in the United States on February 1, 2026 by Atulya
Size: 5 Pound Kit (2 lbs MB, 2 lbs CN, 1 lb ES)
I was a little hesitant about getting into hydroponics because managing the nutrients seemed so complicated. But I decided to take a chance with this kit of ingredients and I am so glad I did! The instructions are explicit and clear and my Kratky jar lettuces and herbs are growing better than they ever did in soil. I make up a gallon at a time, which is an easy amount to manage for anyone doing small scale hydroponics. Good investment.
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Reviewed in the United States on December 21, 2025 by Amazon Customer
Size: 5 Pound Kit (2 lbs MB, 2 lbs CN, 1 lb ES)
Expensive, but works well. Buy salt at store for savings.
Reviewed in the United States on January 8, 2026 by C Good
Size: 12.5 Pound Kit (5 lbs MB, 5 lbs CN, 2.5 l...
Great product
Reviewed in the United States on April 16, 2026 by Foster325
Size: 2.5 Pound Kit (1 lb MB, 1 lb CN, 0.5 lb ES)
This product that I bought was pretty good. I used it in a hydroponic system I was setting up. It was nice to have all three in the combo kit which made it just easier to do rather than trying to buy them individually. the plants grew well and I can't complain about the product. Since the plants grew well, it must have been a good product. Without having to search around for the products individually, I thought the money I paid for it was well worth the price. Don't expect huge bags as it is only a 2.5 pound kit. But the size was perfect for was I was doing and it was what I expected.
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Reviewed in the United States on September 29, 2025 by D
Size: 25 Pound Kit (10 lbs MB, 10 lbs CN, 5 lbs...
Let's dive into the MASTERBLEND 4-18-38 Complete Combo Kit, your go-to solution for balanced and effective plant nutrition! 🌱 Ideal for hydroponic systems and traditional gardening, this bulk kit provides everything you need to nourish your plants with essential nutrients. The 4-18-38 formula is renowned for its balanced blend of nitrogen, phosphorus, and potassium, crucial for robust growth and vibrant blooms. What makes this fertilizer kit stand out is its versatility and effectiveness. Whether you're growing vegetables, flowers, or herbs, MASTERBLEND ensures your plants receive the optimal nutrition to thrive. Since using the MASTERBLEND 4-18-38 Complete Combo Kit, gardeners have seen impressive results in plant health and yield, making it a trusted choice for both beginners and seasoned growers alike. If you're passionate about maximizing plant growth and productivity, look no further than the MASTERBLEND 4-18-38 Complete Combo Kit. It's your key to achieving lush, healthy plants with every application! 🌟
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Reviewed in the United States on July 10, 2024 by Alien Nomad