My Second Grow at 5 weeks

Hey All,
I'm posting progress on my second grow after 5 weeks.
I moved 4 plants into my small tent on March 23. The question and problem I had was how to go from a seed started in a rock wool cube to a 5-Gallon DWC with a 10" net pot and Hygroton.
1 Plant Suffered "Pinching off" at the stem, continued to look good, I isolated her, but she withered off and died on me. (Against advise) I took 3 small clones off her before trashing her.

The 3 remaining Gal's I have been topping, Supercropping the stems (To the best of my understanding) as well as "Tying them down" Pictured a Kind-of L.S.T. topping / super cropping jumbled mess.....

after 5 weeks, I pulled off a few clones from the gals in the tent, I also added an aquarium CO2 generator, which I refresh weekly.
IMHO it doesn't add much, especially with the Carbon filter and the ventilation. But I figure whatever help these plants can get is worth a try.

here are some pictures thus far......

a Great many thanks to this who have helped me along the way here. So far the best advice was simply NEVER GIVE UP on the GROW!

One more week and Im going to start 12/12 HPS Flowering......

Thanks for looking
~S