Grotek Cal-Max

Price Match
£12.49 - £37.99
Grotek Cal-Max
Price Match
£12.49 - £37.99 Save upto: £9.50
Want it delivered by Saturday, 27th Jul?
£6.99 Next working day  (3pm cut-off)
£4.50 Standard delivery 2 - 4 working days (free on orders over £50)
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Grotek Cal-Max

  • Often the limiting factor in fast growing plants is a lack of useful calcium. In fact, it's one of the problems many coco growers face as there isn't a lot in the media.
  • Grotek Cal-Max provides calcium in a rapidly available form meaning your plants can get back to the job at hand.
  • As such, Cal-Max makes a great conditioner, charging the coco with calcium before use.
  • Along with calcium, Cal-Max also offers nitrogen which is one of the most important elements for plants.
  • It also has a strong source of iron in chelate form which also helps keep the plants green and healthy.
  • Using Cal-Max alongside your regular nutrients will help improve overall structure as well as help growth rates.



Cal-Max(tm), which charges soilless media, helps plants recover from minor nutrient deficiencies that can result from nutrient imbalances, rapid growth or too humid conditions. 

Coir-based soil growers need to know about Cal-Max(tm). The availability of nitrogen helps to stimulate the production of chlorophyll, protein and other nutrients that are needed to quickly regreen plants. 

For lush green growth, chelated iron provides more power to combat deficiency. Calcium is an important ingredient that can increase plant vitality and help with peak growth.

Use as a spray on the leaves to speed up your recovery from nutritional deficiencies. This is a great way to pre-charge coco coir.

Applicable Rate: One liter equals 800 litres of solution. Soil/Soilless: Add 5 ml to 4L (1 teaspoon per 1 gal) water. Use as needed. 

Water Culture: Use 5 to 8 ml of water per 4L (1 to 1.5 teaspoons per 1 gal). Use as needed. 

Foliar: Use 10 ml for every 4 L (or 2 tsp for every 1 gal) of water.

This rapid source of magnesium and nitrogen can be used to support protein and chlorophyll development. 

It also helps plants that are low in nitrogen quickly. Chelated iron provides more power to fight deficiency for lush green growth. Calcium is an important ingredient that supports the plant's strength and aids in peak growth.

It is helpful for high temperatures and humidity.Calcium can become a problem during periods of high temperature or peak growth. 

This formula helps to prevent plant damage by driving calcium movement. High temperatures and humidity can prevent plants from absorbing enough calcium, even if there is sufficient. 

To address this problem, you might consider foliar application.Coir-Based Medium Alleviates Nutrient Deficiencies

Cal-Max is a great tool for amending coco-coir-based media. It has fast acting nitrogen and strong calcium sources to buffer the coir's inherent imbalance.

Mainland England & Wales

  • Orders over £50 are Free Standard Delivery.
  • Orders under £50 are £4.50 Standard Delivery
  • Next Day Delivery £6.99

We ship parcels using DHL tracked Service. DHL will send you tracking information by email or text to inform you know when they will be delivering your parcel.

Small items are sent via a Royal Mail tracked service.

Our cut-off time for deliveries to leave us the same day is 3pm Monday to Friday.

In Stock: 1 - 2 Working Days

Out of Stock: 2 - 4 Working Days

Items Marked 'Out of Stock' on the website are not currently available from our supplier. Please call or email & we will update you when available.

If any item ordered is unavailable we will contact you by email or phone with expected delivery times. We only debit orders on dispatch so should you wish to cancel, we will do so.

Free Product Exchange:

We allow 30 days for a product exchange. On receipt of the original unused items we will return your exchange carriage free.

Terms and conditions apply.

Scottish Highlands / Northern Ireland

  • In Stock: £13.99 Delivery 1 to 2 Working Days

The cut off time for deliveries to leave us the same day is 3pm Monday to Friday.

We ship using DHL tracked service. DHL will send tracking information by email or text so you know when they will be delivering your parcel.

Small items are sent via a Royal Mail tracked service.

Free Collection:

Please arrange a collection time and date with our team if you wish to collect your order.