Steering, Runoff % & pH 5.5–6.0
How dryback concentrates slab EC, using runoff fraction to steer salts up or down, the veg-vs-generative lever table, and holding pH 5.5–6.0 with algae control.
8 min read
Runoff is your EC steering wheel
Because stone wool has near-zero CEC, slab EC tracks your feed and dryback almost directly — fast steering, no buffer. As the slab drys back, salt mass stays put while water leaves, so slab EC concentrates: a 6% dryback lifts in-slab EC meaningfully above feed EC. That's the generative lever. To pull EC back down, you flush with larger runoff.
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