PH issues with Grodan 6x6 cubes.

[JuicedFarmer]

With stone wool cubes we must condition them properly to break down the residual lime from processing. Lime is a PH buffer and draws the PH to around 7. We’ve done a number of methods to condition these cubes. Dropped the PH of our soak water to as low at 5.2 along with dropping our EC to essentially 0. We can’t seem to keep our run off readings under 6.6 - 7.1ph. HELP!!

 

[MrGreenfinga]

With stone wool cubes we must condition them properly to break down the residual lime from processing. Lime is a PH buffer and draws the PH to around 7. We’ve done a number of methods to condition these cubes. Dropped the PH of our soak water to as low at 5.2 along with dropping our EC to essentially 0. We can’t seem to keep our run off readings under 6.6 - 7.1ph. HELP!!

Thats really wierd i use grodan 4x4 cubes for my dwc and i never experienced anything like it i dont even soak them
i just let them be

Maybe flush them dont have so much knowledge on how to grow in RW but thats how you get about anything out of any other growing medium

Good luck

 

[monkey47]

With stone wool cubes we must condition them properly to break down the residual lime from processing. Lime is a PH buffer and draws the PH to around 7. We’ve done a number of methods to condition these cubes. Dropped the PH of our soak water to as low at 5.2 along with dropping our EC to essentially 0. We can’t seem to keep our run off readings under 6.6 - 7.1ph. HELP!!

What run of are you talking about ? The run of from your presoak solution? I dont see the point. I only measure the ph value of the rockwool run off after they are rooted and are getting fertilizer.

I soak my rockwool cubes for around 12 hours in ph water at 5.5 with an rootingsolution that does not affect ec value. After that I feed them 5.8 phd water With fertilizer. Never had a problem My run of from mature plants is around 6 ph doing exactly that. I don't use RO water , just tap water.

 

[PooToe]

Weird, You sure your meters are calibrated correctly?