The 3 different options for Rapid Rooters are listed here… Bag of Rapid Rooters. These are round on bottom instead of being a cube, which means they cannot stand up on their own. These are best suited to a hydroponic setup where the Rapid Rooter will be placed directly in the final destination. In our hydroponic setups, we’ve had near 100% germination rates with Rapid Rooters, better than any other seedling cube we’ve tried. Round on bottom (won’t stand up by themselves without support) unless you squish the bottom so it’s flat like this grower did (pic) Great for starting with Rapid Rooter directly in final destination (hydro, soil, coco coir, etc) Get 50 Rapid Rooters at a time.
This type of Rapid Rooters comes in a mat of (usually 98) Rapid Rooters. All the individual Rapid Rooters are sectioned off and have a hole for the seed, but they must be cut or pulled away from the complete mat. Unlike the type of Rapid Rooters that comes in a bag, these ones are made into cubes and are flat on the bottom so they can stand alone. This makes them good for germinating in a shallow pool of water where the cubes need to be able to stand up on their own. Easily break cubes off the mat (already sectioned off with pre-cut holes) Already shaped like cubes with flat bottoms, so they easily stand up by themselves Good for seamlessly transplanting your seedlings somewhere else Get 98 Rapid Rooters at a time. The Rapid Rooters tray is perfect for seeds or clones. Allow your young plants to sit in the tray with water until their roots are well formed and ready to be transplanted to your final destination.
You can refill the tray with Rapid Rooters from the bag or mat. As you can see in the pictures below, the Rapid Rooter Tray comes packaged up. Once you open the package, you will see 50 Rapid Rooters already set in the tray. The resting place for each Rapid Rooter has a hole on the bottom so water within the tray is wicked up. Just add you seeds and pour some water into the tray – the Rapid Rooters will do everything else for you. Perfect for cloning or starting seeds with a humidity dome (standard 10-inch by 20-inch dome like this one – 7-inch height recommended for cannabis seeds or clones) Easy to transplant to new destination Just add water and seeds, that’s it! Whole tray can be refilled with any type of Rapid Rooters (from bag or mat) Comes with 50 Rapid Rooters, ready to go. Rockwool Cubes (Not Recommended) It’s often hydroponic cannabis growers who use Rockwool cubes since these can be safely placed in hydroponic setups, hold a lot of moisture, and are resistant to mold. But it does have some major drawbacks… Pros of Rockwool. Cheap & Easy to Find Inert Medium (useful for hydroponic growers) Cons of Rockwool. Bad for the environment (unnatural material that does not break down) Bad for your health (especially your lungs) – wear gloves and cover your mouth/eyes when handling Rockwool Has a pH that is too high for cannabis, so it must be thoroughly rinsed and treated Poor cloning and germination rates Difficult for new growers. Rockwool is not a natural material – it’s made by heating rock and chalk to 3,000°F and air is blown through the mixture to create thin fibers of rocky material. It does not break down naturally and therefore after Rockwool is created, it will remain in that form basically forever, filling up landfills without breaking down for thousands of years. Rockwool is dusty and needs to be rinsed thoroughly before use. Little pieces of Rockwool and dust can easily get in your eyes, skin and mouth. Small strands or fibers can get lodged in your lungs if you breathe in Rockwool dust, and it’s unknown if these fibers can ever get out again. Always use a mask, goggles and gloves when working with Rockwool. Rockwool cubes have a high pH until they’re treated. New Rockwool cubes have a high pH – too high for healthy cannabis seed germination. Therefore it’s important to thoroughly rinse Rockwool cubes in pHed water, then let them soak in pHed water overnight before use. Since Rockwool holds onto a lot of water, after soaking they should be given a few days to dry out before planting seeds or making clones. Rockwool can be difficult to germinate marijuana seeds in, so I recommend most beginner growers sprout their seeds using another method like Rapid Rooters (mentioned above) which can also be used in hydroponic applications but are less prone to germination problems. Many growers have placed seeds in Rockwool cubes, only to wait for weeks and never see seedlings appear. Some growers seem to have no problems, yet many other growers suffer through very poor germination rates. Some seed companies will not honor seed germination guarantees if the grower uses Rockwool because it is notoriously bad for germination. If you do use Rockwool, it’s recommended you germinate your seeds using another method like the paper towel method, then transplant your seeds to the Rockwool cubes after roots have already appeared. Even when following all the best practices, we just have not gotten great germination rates with Rockwool cubes, and it’s common for new seedlings not to make it.
When we were using Rockwool (before we switched to Rapid Rooters), we usually lost at least 1 seed out of a batch of 6 or 8. Rockwool cubes just don’t hold enough air to get plenty of oxygen to the roots, and they tend to hold onto a lot of water and get waterlogged easily.
Since Rockwool can hold a lot of water, it’s prone to “drowning” seeds.