Pumice is a low cost and readily available hydroponic media, which is mined in New Zealand.
The pumice supplied by Pure Hydroponics is mined from a land-based resource, within 50kms of Lake Taupo in the North Island of New Zealand. It is characterized by its relative hardness and lightweight in comparison to competing aggregates.
This porous volcanic rock allows for good water retention and aeration, and the use of a combination of fine and coarse materials allows a grower to manipulate the drainage capacity of the media. The surface tension around the outside of the pumice particles further increases the water holding capacity of the growing medium.
Pumice can also be mixed with other types of growing media e.g vermiculite or coir, to achieve desired results.
Pumice is slow to break down and is very lightweight. Its light-coloured appearance makes it an ideal media for summer growing as it does not attract heat.
It is popular for tomatoes and capsicums grown in bags, or lettuces and herbs propagated in NFT growpots.
Pumice is graded and kiln dried to 80 Degrees C prior to supply which means it is sterile and ready to use. Dust is eliminated as part of the screening and washing process.
The following grades are available:
- 1-2mm
- 1-7mm (Most popular for hydroponics)
- 4-20mm
- 7-20mm
Available in:
- 25 litre bags
- 1.25m3 woven bulk bags (20 Bags per 20′ container)
- Full 20 or 40 foot open top container loads.
How Pumice is Naturally Formed
Pumice is a light, porous volcanic rock that forms during explosive eruptions. It resembles a sponge because it consists of a network of gas bubbles frozen amidst fragile volcanic glass and minerals. All types of magma (basalt, andesite, dacite, and rhyolite) will form pumice.
During an explosive eruption, volcanic gases dissolved in the liquid portion of magma expand rapidly to create a foam or froth; in the case of pumice, the liquid part of the froth quickly solidifies to glass around the glass bubbles.
