I like this TEK except for the sand part. I recently just started sowing directly onto soil. The sand seems to cause problems with them establishing as they get a little bit bigger. I like sowing directly on soil so they have fast access to nutrients. In my mind, bigger seedlings faster means fewer problems as they get older.
For now I'm using:
8 parts potting soil, 1/4" screened to remove big chunks
4 parts coco coir
2 parts perilite, also 1/4" screened
I put the soil in the container, wet it till it's fairly damp but not soggy, sprinkle seeds on top, thoroughly mist with water, cover with saran wrap, T5HO 4x bulbs about 18" away, heating pad (65F nights, 95F days). When i see anything that looks like mold, I mist it directly with 70% Iso-alcohol, the seeds/seedlings don't seem to mind it.
I don't worry so much about uncovering them to mist when I feel like it.
Hcc