Yellowing and brown lower leaves

Hello I seem to have a problem with two of my vegging plants it seem as though they bottom leaves are yellowing and turning brown
Now they are in 1 gallon pots right now with FF happy frog and getting top fed with dr.earth dry amendments and only PJ's water under a mars hydro SP350.
I am going to flush tonight, if anyone could please help diagnose my issue would be greatly appreciated thanks roll it up!!!
Will attach photos

They look hungry to me. I would use the dr earth to make a nutrient tea. Nice work on that manifold. Very nice!

The last thing I'd do is flush.

How much

HydoDan said:

They look hungry to me. I would use the dr earth to make a nutrient tea. Nice work on that manifold. Very nice!

Click to expand...

How much Dr earth do you suggest I use for the tea would it be the same 2tbsp per gallon?!?!

I use a half cup to one gallon. There is a tea recipe on the package.