Backyard Aquaponics
A place to discuss aquaponics

Please help

Always hard to tell from pics, but I would suggest it's possibly Calcium deficiency. If your pH is in the low 7's or lower, you could try a slightly heaped teaspoon of Calcium hydroxide (brickies lime) per 1000L. Dissolve it in a cup of water first, then add it into the GB at the start of a new flood cycle, so it has time to mix with a good volume of water in the GB before it is then dumped into the FT.

I think the second picture is not a deficiency but probably a disease (either a small acarid "Polyphagotarsonemus latus" or cucumber mosaic virus).

+1 on the last comment. First thing I thought of when I saw that pic was spider mite damage of some kind. Check the underside of the leaves. Sometimes putting a piece of white paper underneath and brushing the underside of the leaf so that they land on the paper will help you see them. There are a lot of different spider mites - mostly they are a problem when the temperature is above 80F.