What am I doing wrong?

[knothead]

Ok so user name says it all! Haven't grown or smoked weed in over 25 years and thought it was time to revive my bad habits. I'm trying DWC with White Widow autos from Nirvana. 3 seeds were put in rapid rooters that were in hydroton with an emitter just below the plug on 1/19 and all 3 emerged on 1/22. Water from tap is 44 ppm and about 7.5 ph. Using GH nutes and ph down + hydroguard water is adjusted to 5.8 (eases up to about 6.5 before readjusting down) and 340 ppm. Tent temps range from mid 60s at night to upper 70s when the lights are on. Water temps are ranging from upper 60s to low 70s. Light is 6 50w Vero 29s at about 20 inches in a 3X3 tent. This is what they looked like at 1 week on 1/29


Thought I was doing ok at this point. Maintained routine and in a few days noticed yellowing on bottom set of leaves only. This pic is on 2 week from emerge. 2/5

Getting concerned about the yellowing so I called company I bought components from to ask about light heights and quantity. They assured me that 20" was plenty of height at full intensity(actually could go lower) but recommended that I get an oscillating fan and direct it between canopy and lights. I already had a small clip on fan which was just stirring the air up but not directed near the plants. Put the fan in and changed out the water(1st time) and went from 3.5 gal buckets to 5 gals on Thursday. This is today...

Not nearly as concerned with the yellow bottom leaves as I am with the overall size of the plants. Shouldn't they be larger? Never heard of autoflowers until about 3mos ago(told you I have been gone a while) but seems to me if they will be done in 12 wks they should be growing faster than this.
So.....what am I doing wrong or what am I not doing that I should be?

 

[knothead]

Don't know how the pics got upside down?!? Looks like I'm as good at posting pictures as I am at growing. Thanks in advance for any direction

 

[Rev. Green Genes]

Heya @knothead sorry it took us a minute to answer. They should be bigger at about 20 days or so, but those roots look good. They can be late bloomers, thats ok. The crinkled drooping is of more concern. The yellowing underneath tells me she is ready for some more nutes. At 20 days it is ok to bump up to around 450-550 PPM. I would bet that the slow growth is in part the fluctuating pH. It's pretty crucial to keep that stable, I go for 6.2 for seedlings, and when they put on a third node with leaves I drop it to 5.8 with a first feed. The manufacturer of those cobs may say 20 inches, but that is for when they are in flower. We usually recommend with autos that they be 30 inches. I think that is your first problem, and is responsible for the drooping and crinkly look.

 

[knothead]

Thanks for the advice. I increased the nutes and I will raise the lights. Hope I haven't doomed the grow.