Dude don't be so hard on yourself, I thought exactly the same when I started.
Discovered the only decent usable bottle water is fizzy carbonated for older seeds.
I agree with dankbongula above, you need a PH assessment on your soil-water.
Otherwise without a PH assessment you could be shooting...
Let the rock wool cube dry out a little and keep it out of medium until it is showing fresh growth. Use PH water then something designed for clones or ornamentals at a low dose.
Wait a week or two then transplant it to a weak cutting/seedling soil.
That's how I would save it.
Treat it like...
Also one of the few I've found with a "freshness guarantee" meaning complaining about germ rates "freshness" they fix the issue.
For all brands not selected and a 200% price match guarantee.
Plantmagic better quality thicker version of biobizz really.
I use it still on mums for the benefitials .
Plus they have a few more boost's a PK 4/8
Pics on my avatar are PM.
PM is also £20 for both and biobizz about £23
Yeah it's cleanest I've ever used. As a wetting agent in it so it soaks it nice.
Soil always comes out at 6.5 PH flowers fly so fast.
When using the hydro version it's so clean my equipment still looks new.
The shogun
EG Week 4 Ice