recent S/H transfer- Miltionopsis new growths are tiny

[Ray]

Wicking rate is a fixed factor. It may vary from brand-to-brand of LECA, but it simply does not change.

Evaporation rate, on the other hand, is affected by temperature, humidity, and air movement.

If W>E, the medium stays saturated all the way to the top. If E>W, the top dries out. The greater the difference, the more of the pot volume will be dry, giving the appearance of the "dry line" moving down (it's actually a gradient, not a sharp demarcation).