UPDATE: After years of running hydro, I have come to the conclusion that starting the plants in rapid rooters instead of rockwool is better.

Rockwool still needs to be sterilized and the main issue with it is oversaturation since cannabis seeds and sproutlings are very easy to drown. Here is Proof

Starting and growing cannabis or weed seeds in rockwool cubes is easy if you follow the steps in this tutorial. We’ll show you the best way to start seeds in rockwool cubes, how to prepare rockwool cubes by presoaking them and ph balancing and when to transplant rockwool seedlings.

Starting marijuana seeds in rockwool cubes is an easy and effective way to encourage rooting because they are sterile and they have a material that can retain water yet still allow significant amounts of oxygen to the roots. Rockwool is a reliable growing medium for cannabis seeds, especially if you plan on growing the plants in hydroponics.

Here are the basic steps for germinating seeds in rockwool:
1.Soak rockwool cubes in one pint of water that is pH’d down to 5.8-6.2
2. Remove from water and squeeze gently to release excess water.
3. Make sure you spread the rockwool cube back out so the cube does not remain compressed.
4. Add marijuana seed to the hole, butthole up only about a cm from the top and plug the hole with a corner.
5. Place into a humidity dome in a warm room with 24 hour lighting and low light. 85 degrees works best.

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  1. What ppfd app did you use

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