.....i donno if this is right tbh? Odlaw hit the head on the nail i thought? As you said retros are to save the cost of buying a seperate ballast. Digitals however tend to be designed to run both without the need to use a retro (ie. Just run a standard HPS and MH on the digital). Magnetics however require the use of the retro.
.
.
.
.
SIDE NOTE: Seem to have fucked up on my r/DWC as the Jock isnt too happy

I have fed them NO nutes yet (they in clay balls) but i am feeding them root tonic and H2O2. It's a two bucket system and one of them was to be used to spray with CS and turn male. The problem is it seems the CS plant is turning brown/yellow on the edge of the leaf and curling up. Its not TOO bad but its noticable and seems to be getting worse

The non CS one is SLIGHTLY yellow but in the centre of the leaf and no curl.
Im thinking maybe the [H2O2] is too high or maybe the Ph is too variable (5.8 - 7.1), but then this would cause problems in both plants? Has anyone used CS (looking your way GOD) and then had the plants go funny on them?
Also i got one of those digital microscopes.....they fun to look at plants

.....and various body cavities lol.