slight yellowing on new growth

Ive seen this in the past, the plants have always finished strong, however I have some plants with out the yellowing and some with, Any ideas. Ocean forest happy frog dry fert. 1 shot of cal-mag a week ago. some worm tea. These are 4 pics from 4 different plants, two of the 4 seem to have the issue. over all appearance of health of the plants is great.

Sulfur deficiencies? that what it appears to me. I will add some EPSON salt next water. Ill start low.

Its new growth...nothing wrong with it

ok, what threw me off is its only happening to 2 of the 4 plants one more so than the other. Thanks for the chill pill bro- Peace

One thing I am curious about is Lock out, now I started in FFof , but then decided I was going to run the organic dry ferts, and big bloom (which is organic) and my own worm casting / light Molasses teas with mycorrizal. I have given two doses of tea since there birth. any way to the main point and that is I have not been PH'ing my water. My water It sits in a 30 gallon trash can, that I keep an air stone in to rid the water of chlorine and I have a aquarium heater just to keep the water above 70. I was told not to ph. Unless using FF other nutrients Big grow and tiger bloom?

Ok, so I agree that it's just new growth. However, I would still add sulfur in regularly... just as important as calmag.

Yellowing new growth is often a sign of iron lockout from too high ph.
Just like yellowing from the bottom up is often a sign of nitrogen (deficiency or) lockout from too low ph.
However, yours are not yellow enough to indicate this.
They look super duper healthy, and fine

They look fine. I've seen it before. As long as the lights aren't to close I'd suggest looking to see if there are any "hot" spots created from your reflector. Some reflectors spread light more evenly than others. Those that don't do it well. Have spots where there is a higher concentration of light then the areas around it. And it doesn't have to be directly in the center of the reflector. If those 2 plants have been in the same spot (I rotate mine around the area until they get mid flower) put your hand above the plant and notice the heat from the light and compare it to other locations. If it's bad enough to cause a problem you'll be able to notice. Think sunburn.