What's wrong with this plant?

[Elaine Sanders]

Hey there,

Can anyone give me input as to what is wrong with these plants?  I did have spider mites but I believe I have gotten rid of all of them. My AP system in indoors.  Is this a light issue, nutrient issue, ph, or insect issue?  I'm not very knowledgeable when it comes to gardening - kinda learning as I go.  My PH does tend to run on the low side - around 5.

[Allisyn Wood]

Thanks. Disregard the question in the other post. I'll test in buckets first. I should need less as my tank is much smaller than yours ( only 110 gallons). Can't wait to get this right! I love aquaponics! What an amazing solution! Happy Thursday!