Good Morfnoevight all you happy Friday stoners.
7 gallons of good TLS will grow an Autoflower from seed to harvest water only - no problem. The guys in the earth boxes do it regularly. The thing is you are only one step away from perpetual growing by feeding the soil. This is what most good soil growers evolve to.
I see P and Mg problems in the leaves. The dark purple stems can be genetic but too much Mg can accentuate the flush. My guess would be too much N is locking the Ca so you added extra Cal-Mag and now the high Cal-Mag is locking out the P. I have had a lot worse finish just fine.