Hydroponic Growth Medium: Rockwool or Starter Plugs

Both mediums have small precut holes perfect for plant stems. You can also start your own small hole somewhere on the cube for stems.

Hydroponic growth medium is an important choice depending on your grow style.  Different growth medias have different strengths and weaknesses.  Many growers turn to hydroponic growing methods for their propagation systems.  By doing so, growers are given a wide array of options to optimize their growing efficiency.  Economical growers do not want to see a decrease in yield or harvest quality due to a growing media issue.

Cloning medium
Try different cloning mediums to find what works for YOU.

Below are the pros and cons for both mediums.  You should experiment with both to see what you find.  You never know what you may find out from trying different soil less mediums.  Search for what works best in the system you use.

Starter Plug Pros:

-Simple, Plugs usually come in a float n grow type system with instructions.

-Only need to be dipped in water to be ready to go.

Starter Plug Cons:

The float n grow system is not really re-usable, rendering the starter plug replacement packs nearly useless.

-Aside from the float n grow – the starter plugs seem to be susceptible to powdery mildew but careful planning can defend against it.

Rockwool Pros:

-The design is made to give the roots the best air to moisture ratio, if used properly.

Rockwool is not messy whatsoever.

-Holds moisture well – Important for cloning.

-Comes in various sizes.

Rockwool Cons:

May not be a good choice for plants that require a dry start  for success.

-Rough handling, and lack of attention could lead to an incorrect air to moisture ratio.

-Should be sitting flat.

I cannot say which will prove to be more successful to you, but I had better luck with the rockwool cubes.  The Starter Plugs stayed in water for too long.  I also tried re-using a float n grow through multiple sets of cloning cycles.  The float n grow needs to be cleaned and sterilized to go through a refill.  The rockwool cubes did not do well sitting in a flood tray of water, but they did hold up well in a bubble cloner.  Go for 100% and try out all the different cloning mediums!  Share your experience below!

4 thoughts on “Hydroponic Growth Medium: Rockwool or Starter Plugs”

  1. I like the Rapid Rooter Starter Plugs b/c they have just enough micro nutrients to get the seeds off to a decent start.

    In the past, I’ve had problems beginning seeds in rockwool. I would of course soak it overnight in 5.5 water, but adding a VERY low dosage of nutrients was always the question…. Should I wait until I see true leaves? Or just add a little.

    The end result, no matter which method I used, seems to be a little nutrient burn, or not enough nutrients to begin with.

    I just got a product called UBioGrow and Im testing it out. Im spraying my rockwool starter plants with it and they’ve seemed to pick up the past few days. Im going to write a full report on my blog after I do some more test and gather more pics 🙂

    The rockwool nutrients that you can buy(specifically for rockwool starters) would be great (I imagine), but I dont have the money too add more to my nutrient collection…lol. I have enough already.

    So in conclusion, I will be using both in the future, but Rapid Rooters Plugs are my preferred choice if I know Im not going to have time to mess with nutrients, ph, ec..etc… I just start them in the plug, and move them over to a bigger rockwool cube when the true leaves appear. (Soaked in low nutrients over night @ 5.5 ph)

    The only down side with Rapid Rooter Plugs, is that it can throw the ph off in your system slightly. But that isnt a problem after about a week or two.

  2. @Outdoor Hydroponics – Thanks for reading!

    I would try germinating the seeds in a wet papertowel in the dark until the tap root sprouts. From there you can put the seed tap root down in the rockwool. I soak rockwool in plain water for seeds and very light nutrient solution for rooted clones. I wait to feed plants until they get the first yellow.

    I would love to read about the UBioGrow – Please send me a link or tweet me @HydroHelp.

    I have also put clones that were rooted in starter plugs into the three and four inch rockwool blocks. They work well but it is easy to damage roots as they are first starting to come in contact with the rockwool. The roots needs to strengthen into the rockwool before moving the plant.

  3. Thanks for the info. If Im putting the seeds in rockwool, I usually use the paper towel method 🙂 I forgot to mention that since I’ve only been using rapid rooters for months now…lol

    Here is the link to Ubiogrow. It’s an all natural product and from what I can tell, pretty much a worm/compost tea that doesnt expire (unlike the rest on the market). So far, Ive used it as a foliage spray and I’ve seen good improvements. Im going to be doing more controlled test, to document the improvements of the plants indoors. Here is the link: http://www.ubiogrow.com

  4. Anyone know whats happening with aeroform at all?

    Have they gone bust?

    Seems a bit odd, Aeroform were a huge business.

    Thanks

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