• Do you need help identifying a 🌶?
    Is your plant suffering from an unknown issue? 🤧
    Then ask in Identification and Diagnosis.

seeds germinate in rockwool.

Rockwool has a high pH, you need to bring it down w/ acid. After that it's pretty easy, just don't let it get bone dry or stay too wet.
 
ZanderSpice said:
Rockwool has a high pH, you need to bring it down w/ acid. After that it's pretty easy, just don't let it get bone dry or stay too wet.

How is that achieved? Sorry for the newbie question ;)
 
You adjust the ph of the water or water/nute solution you're using with the rockwool. A PH of 5.8 seems to be ideal.

The purpose of pre-soaking rockwool is to flush out the alkaline residue left behind by the manufacturing process.

The pH of the soak solution doesn't matter too much, but the lower the pH the faster the deposits will be dissolved. pH < 5 breaks down rockwoool and should be avoided. At pH 5.5 you only need to soak for a couple of hours, at pH 7 or higher you should soak overnight.

After soaking, flush it out again with your starting solution @ pH 5.8.

If you are starting seeds you can use plain water @ pH 5.8.
 
JJBagoose said:
How is that achieved? Sorry for the newbie question ;)

With some Ph Down solution. Or you can drop a higher Ph'ed water (most socal tap water is like in the low 7's) w/ some lemon squeezin's.
 
I don't know where people get rock wool with Ph problems. I have been using it for years and Ph stays about 6.5-7.0 with no input from me other than municipal water.

The cubes work just fine for germination...keep them warm and wet. You can transplant the cube to either hydro or dirt.

crop3400.jpg


IMG_3399.jpg
 
I soak mine in rainwater first (ph tends to be 5.5 - 5.8) and then water with a weak nute solution. No ph adjusting needed with rain water.

Chris
 
I don't think the PH is that big a deal with rockwool either. Just don't over fertilize the seedlings since RW has no nutrients. Very diluted nutes work well. And make sure the roots are coming out the bottom of the cube before you place it into a bigger environment. I killed quite a few seedlings last year because the soil around the cube was moist, but the cube itself was bone dry. It seems Pro-Mix will suck the moisture right out of the cube. Make sure the roots contact the outside medium.
 
Back
Top