what is rockwool?
Rockwool (also known as mineral wool and stone wool) is an efficient way to grow marijuana and all kinds of plants, particularly for hydroponic systems. It is a substance that has been melted from basalt rock, into a lava, which is then spun, making a cotton-like stringy fibre. This is then made into blocks or cubes, that come in a range of sizes.
It can be a great medium to start off your young cannabis seedlings as the material means it does not disrupt the root system. Rockwool is also used in the construction industry for insulation.
Rockwool is a popular choice amongst growers and has been used for over 40 years, particularly in hydroponics. It is highly absorbent and has great water retention.

preparing rockwool
Before you begin to use rockwool, you need to prepare it first. Naturally, it is too alkaline for cannabis (pH 7.0), resulting in poor nutrient uptake. You will need the adjust the pH level. Before using, you should soak your rockwool in water around 5.8 to 6.3pH level for 24 hours.
When the water or nutrient solution is running off at around 5.5pH, then it is ready to use. If not, soak it for a few more hours and test the pH level again. Without squeezing the remaining solution, let the rockwool air dry, allowing for the air into the rockwool block.
rockwool in hydroponics
Rockwool is an extremely popular choice for hydroponic growers and can work well with NFT, flood and drain and drip systems. When plants are sitting in a rockwool slab, the top of the slab is usually drier, giving the plants more room for aeration and oxygen intake, which is great for respiration and root development.
The bottom of the rockwool slab will be drenched in water, allowing good moisture for your plants. Th rockwool ideally would work best if placed in a position where only the bottom half is sitting in water, as in the NFT system.

transplanting seedlings to larger cubes
With rockwool, its easy to transplant your seedling once it has outgrown the starter cube. Simply buy a larger rockwool cube and cut a hole in it, large enough for the smaller cube to fit into. Then place the cube with the seedling in it, into the new larger cube. The roots should then develop and spread out into the new cube.
maintaining your plants in rockwool
Be sure to fertilise every time you irrigate, allowing for up to 30% of the fertiliser to be washed away as run off. Do not let more than 30% run off, as this could cause the rockwool to dry up and therefore cause stress to your plant. Rockwool can hold a lot of water, so try not to overwater your plants.
As long as the plant is healthy and the pH level is around 5 to 7.5, your plants should do well, but do monitor the pH levels to check everything is as it should be. Using rockwool allows you to have complete control over the nutrients going into your water solution.

a disadvantage of rockwool
One disadvantage of using rockwool it that it is not re-useable and will not biodegrade. Re using rockwool can cause problems with fluctuating pH levels. It is best to start with a new cube of rockwool for each grow.
AK-47 Feminized
Ak-47 was orginally created by the Netherland’s Serious Seeds in 1992 and has won 16 awards including the High Times Cannabis Cup. People love this strain around the world for its high THC content, strong flavour and high energy effects.
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Amnesia Haze Feminized
10% Indica – 90% Sativa | THC 21-25% | This is THE legit Dutch classic Sativa dominent powerhouse that is the proud winner of multiple Cannabis cups. This uplifter has a lemony, incense and cederwood flavour. Amnesia has a slightly longer growth phase overall, but this translates into massive yields and is well worth your attention for a truly supreme quality end product that is sure to please those aiming for a happy and uplifting high.
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Is it legal to buy Cannabis seeds in Australia?
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Gelato Feminized
70% Indica – 30% Sativa | THC 21-27% | This strain is an absoluate corker! One of the nicests strains going around in our opinion and very under rated. Super strong, Very crystally large(ish) buds with very big yields. It’s fairly straight forward to grow and super strong.
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Is it legal to buy Cannabis seeds in Australia?
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Gorilla Glue Feminized
50% Indica – 50% Sativa | THC 20-26% | One of the strongest cannabis strains available this one is recommended for the serious marijuana consumer! This popular strain has also won several cannabis awards like the Michigan and Los Angeles Cannabis Cups in 2014, and the High Times Jamaican World Cup.
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Is it legal to buy Cannabis seeds in Australia?
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Grapefruit Feminized
20% Indica – 80% Sativa | THC 16-20%
The Vancouver, Canada staple…. This 80% Sativa strain has a sweet and fruity aroma similar to the smell of ripe grapefruit It’s an 80’s old secret mix of Cinderalla 99 with a mystical grapefruit flavoured Sativa.
With the smell of pineapple and grapefuit this has an uplifting & stimulating high good for focus, creativity and pleasure.
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Is it legal to buy Cannabis seeds in Australia?
How can I buy Cannabis seeds in Australia?
Northern Lights Feminized Seeds
90% Indica – 100% Sativa | THC 16-18% | Northern Lights is definately among the most popular strains worldwide for it’s stable phenotypes, fast flowering and easy to grow persona that works well indoors and outdoors. This strain is remarkably resiliant and well worth your attention as a beginner grower.
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Is it legal to buy Cannabis seeds in Australia?
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OG Kush Feminized
75% Indica – 25% Sativa | THC 18-23% | The classic californian OG Kush is referred all over the world. This strain loves hot temperature and is the proud parent of many popular strains such as girl scout cookies. OG Kush has very high THC levels and is well known for it’s full body high and spicey aroma.
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Is it legal to buy Cannabis seeds in Australia?
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Sour Diesel Feminized
40% Indica – 60% Sativa | THC 19-24% | Sour Diesel is a very strong well balanced sativa dominated straing with a unique diesel fuel odour when smoked. Around for over 2 decades, it’s a cross of Chemdawg and Super Skunk so it has an intense flavour and aroma with notes of exotic wood, lemon, spices and of course diesel fuel when smoked.
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