6 days later
Still using low strength canna coco (0.5ml/L) with calmagic (1ml/L) now. Tap water here has an ec of 106 for a total ec is 540.
Will soon be doubled to half strength.
Here's some progress - seeing third set of leaves opening nicely although one plant is slower than the other two.
Seems like 61 actual watts of LED is enough to give reasonable growth and the "gas lamp" schedule does not appear to be harmful?