Roots

And while we are at it, another pepper plant in soil. This one has been this way for weeks without any growth.

The first picture is probably too strong a nutrient solution.
the last picture looks like magnesium or iron deficiency.

I added some iron and mag to the second in the hopes to save it. I drained over half of the hydro solution and added fresh water. Thank you for the help.

if you are using a general plant food, which will work if it has the micro's, you will need to add epsom salts about 1/4 tsp per gal of nutrient and calcium nitrate, amount based on how much nitrogen the fertilizer has in it already. this will take care of the Ca, Mg ,and S. if the micro's are not chelated the ph will have to be maintained also.