Erica: I think you'd be better off asking in the hydro forum and/or the Garden Clinic forum.

Keep us updated though.

Kevin

Kevin,

Thanks for the tip. I'll give that a try.

State (or show) whether the discoloration affects the younger or older leaves differently. Some apparently similar symptoms mean different things according to which ones they affect.

Dennis

Dennis,

I went out and took a good look at it. Some of the young leaves look healthy and some look like the picture. At one point, thinking it might be a disease, I removed most, if not all, of the affected leaves. However now that it has leaves again, you can see that the problem has remained.

If it's on all the leaves, then I'd suspect a manganese deficiency. There could be plenty of Mn available but with something preventing its uptake.

See what the Hydro forum says.

Good luck,
Dennis

Actually, now I'm suspicious about all those tiny spots. Do they brush off? Can you see if it is dead cells?

Dennis

Dennis,

The tiny spots do not brush off. I did post on the hydroponic forum and the garden clinic forum, both last night. Looks like the only reply I got on the hydroponic forum was from you!

I will definitely look into the manganese though!

Thanks,
Erica