Seramis - Clay Granulate
  • Seramis %28both sizes%29   clay granulate
  • 84979 30 litre seramis   clay granulate
  • 84980 7.5 litre seramis   clay granulate

Seramis - Clay Granulate


Choose your size of media:

7.5 litre (Out of Stock)

£10.95 £10.95
Seramis - Clay Granulate
  • Seramis %28both sizes%29   clay granulate
  • 84979 30 litre seramis   clay granulate
  • 84980 7.5 litre seramis   clay granulate

Seramis - Retains More Water than Any Other Clay Substrate!!!

Seramis Clay Granulate is a fine grade of fired clay that’s becoming more and more popular with growers everywhere! It holds an incredible amount of water, even beating that of soil or coco, yet its granular structure still allows free drainage. Great stuff!

  • We offer large volume, international shipping. Please contact 01782 749 955
  • Seramis – bringing new and exciting grow products
  • Clay Granulate – the new alternative to clay pebbles
  • Only the highest quality clay used in its production
  • A special clay extraction process and low temperature firing produces an incredibly porous surface
  • Granular consistency allows free drainage for great oxygenation and disease resistance
  • Strong capillary action and water retention - holds 100% of its own weight in water
  • Very stable and completely inert, with a natural pH of 5.2 to 6.0 and a very low natural salt content
  • Can be mixed into soil, coco or soilless mediums to improve drainage
  • Does not disintegrate - can be cleaned and re-used many times
  • Allows increased nutrient uptake
  • Growers everywhere report great results using Seramis


1 x bag of Seramis Clay Granulate. Choose between 7.5 litre and 30 litre bags.

Recommended additional purchases: 

Canna Hydro Nutrients (for run-to-waste systems) or Canna Aqua Nutrients (for recirculating systems)

Silver Bullet Roots (oxygenates the rootzone, while preventing diseases like pythium) 

Keep it Clean (prevents mineral deposits from forming in your system)

Hygrozyme (breaks down dead roots turning them into available food for your plants)

How Seramis Works:

Seramis clay granulate is made up of small, fairly regular-shaped granules of expanded clay. This particular clay is top quality and actually found only in the Westerwald region of Germany. The clay undergoes a careful process to give it its unique properties. First the clay is diluted with water and then it undergoes a special porification process to achieve an incredible pore volume of over 80%. The clay is then dried, broken down, sieved and then fired at a particularly low temperature which helps to even further increase its water-holding properties. The granules are then washed to remove dust before being carefully packaged.

Seramis clay granules are hard, which stops helps stop them from compacting down, allowing free drainage and good oxygenation of plant roots. The superb surface porosity allows each granule to hold 100% of its own weight in water. Because it holds so much water it can be used as an alternative to soil and coco when hand-watering, or as an alternative to regular clay pebbles or coco in a hydroponic system. Seramis has a natural pH of 5.2 to 6.0 and has a very low salt level.

How to use Seramis:

Seramis clay granulate can be used as an alternative to soil and coco when hand-watering. It can also be used as an alternative to regular clay pebbles or coco in a hydroponic system. It can be added to soil to improve drainage and reduce clumping. Seramis clay granules can also be used to top-dress soil or coco to reduce evaporation.

Seramis clay granulate is washed before being packed. However, before using it is a good idea to give it another wash to remove any dust produced during transportation. It has a natural pH of 5.2 to 6.0 so usually does not require pH adjusting but it can still be soaked in pH-adjusted water before using, if you wish.

Once the Seramis clay granulate has been prepared, place it into your pots/system and carefully transplant your plants into it. 10-15 litres is usually adequate for medium sized plants. For larger plants use more. Make sure the root-ball is covered (i.e. buried below the surface of the granulate and not sitting on the top of it). Water well or run your system for several minutes to prime it with feed-water/nutrient solution. Most hydroponic feeds that are suitable for use with traditional clay pebbles are also good for use with Seramis clay granulate. Remember to check and adjust the pH and the strength of your nutrient solution regularly, if possible on a daily basis.

After your grow, the medium can be re-used. Simply remove the roots and wash it thoroughly. Using an enzyme product will help to break down any remaining root-hairs. Doing this means that it can be used many times over, making it a very economical medium.

JOE GROW'S TOP TIP 1: Seramis clay granulate holds a heck of a lot of water so plants grown in this medium require less frequent watering than when they are grown in traditional clay pebbles. If you water too frequently then we have found that this will almost certainly discourage root-growth and can make your plant's roots vulnerable to root diseases like pythium. For plants that have just been re-potted into Seramis clay granulate we would recommend watering once per day at most and probably less, if possible. This is in order to allow the medium to dry out a little in-between waterings which encourages the plant's roots to grow out in search of water. Allowing the it to dry out a little in-between watering cycles also helps to keep root diseases at bay. For hand-watering, Seramis clay granulate holds as least as much water as soil or coco does, so do not water more frequently than you would do in those mediums.

No matter what your style of growing, if you still experience sluggish root or plant growth, try House & Garden's Roots Excelurator which protects the roots from disease and turbo-charges root growth like nothing else on earth - superb stuff!

JOE GROW'S TOP TIP 2: Placing an airstone into the middle of the Seramis clay granulate, connected to an external air-pump via an air-line, supplies extra oxygen to your plant's roots and can give a worthwhile increase in the speed of growth. Always remember to place your air-pump above the highest level of the waterline in your system and to also use a check-valve in the air-line. This will prevent any possibility of “back-siphoning” of water into your air-pump (which will cause it damage) in the event of a power outage.

Natural pH value - 5.6