TheBioMaster said:

In rockwool you should always be using nutrients when watering.....straight RO water is not good for plants.

RO water is used when your source water has to high of a TDS reading.......and without testing, you don't really know what is in it and in what amounts, etc.

In most cases the amounts do not interfere with the nutrient system used.....but not always. Lockouts can occur depending on several factors.

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TheBioMaster said:

Lower the amount of nutrients used if the plants show signs of overfeeding. The amount of water and frequency must also be dialed in.

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nemgrower202 said:

But wouldnt that be overfeeding them? When i used to grow years ago i always used to add nutrients each time i used to water them. But now i've been told that i am overfeeding them and to add nutrients every other watering.

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youngOG said:

usually the problem with rockwool, is not too much nutrients in the feed but rather salt acumulations that happen in the media
when you let it dry out a bit to let it breath before watering again, some salts that were dissolved in your hydro solution will crystallize and get trapped in the medium
if you measure the EC of your runoff you can get crazy numbers

the solution ?
give big runoff each watering , enough to get EC feed = ec runoff

feed around 1.5 mS and your good
dont let the salt burn your plants

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nemgrower202 said:

Thanks for the info. when i used to run the system 15 years ago i used to run it long. Now im running it a bit less cause im afraid of over watering. but i give it a bit of a runoff

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youngOG said:

rockwool overwatering happen with too frequent watering
big runoff will never harm
you can let it runoff 10 min without any symptom of overwatering

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