Please help diagnose my plant problems!

*I moved this topic here after realizing i posted in the wrong forum.

So here are my problems..

1. Is that normal for two plants of the same strain started at the same time to have major growth differences?
2. New leaf sets are coming in twisted as you can see in the pics. What could be causing this
3. Is the pale green in the middle of current and new leaf sets nutrient burn or nutrient deficiency?

The strain is bubblelicious Auto Fem from nirvana
Running 18\6 light sched under a 400w MH
Ph in water is checked daily and is kept in a range between 5.5 and 5.8
I have one 160cfm fan for exhaust and another to air cool my hood
I also have an ionic breeze type air filter in the tent and well as ac being vented in through the bottom to keep temps in the 70's
Room temp stays between 75 - 79 degrees (last week my ac messed up so the temp was in the low 80's for about 3 days.)
Both plants were started at the same time about 6 weeks ago (so much for auto i guess?)
Using Bubble Buckets with clay pellets and rockwool.

Pics are below. Thanks for your help in advance!!

View attachment 1184560View attachment 1184558View attachment 1184561View attachment 1184559

Can anyone let me know what my problem(s) is\are?

1. It's fairly common due to phenotype and gender differences. Males often grow taller/faster.

2. Gnarled fresh growth is usually a Ph problem. Yours are only very slightly gnarled so I doubt it's off by that much.

3. The lighter green on fresh growth is normal and should get darker as the leaves mature. It's hard to tell for sure from the pics, but it looks a little like some of the lower leaves have darker veins and lighter leaf in between veins. If that's the case, it's a symptom of either a magnesium or zinc deficiency.

Many reasons one might mature faster, couldn't really speak to that but the new growth looks fine, nothing abnormal about it that I can see in the pics. Here's a couple of pics for comparison (the crap on the leaves on the small plant is sawdust).

I appreciate the help guys, my main concern was the light green coloring of the new growth. I thought it might be lack of Nitrogen or maybe even too much i just wasn't sure. As far as the twisting of the leaves go i too have heard it could be a ph or heat issue... My res water got pretty warm when my ac died out mid 80's and it was like that for 2 days until i bought a few ice packs to cool it down. I usually check the ph daily and make adjustments and it's never far out of range....the highest i have seen it was at about 6.0 I know hydro should be kept between 5.5 and 5.8 but 6.0 can't be too bad for it right? Considering in soil it can go as high as 6.5. So tomorrow im going to give both plants a thorough flush, change the res water and hope for the best.... now if only these damn auto flowers would start to flower!! My last grow went great. a quarter pound off two bag seed plants. I was very happy. Now i just want these ladies to share their fruits with me!