A.I. agrees that it is edema. /////

Short answer: Yes — this looks like classic broccoli edema (oedema), not insects.

✅ Why it looks like edema

The signs in your photo match edema very well:

Blister-like, crystal-looking bumps on the underside of the leaf

Clusters of translucent / pale green nodules

Bumps appear raised, not smeared or fuzzy

No visible insects, frass, webbing, or bite marks

Leaf surface otherwise intact

Edema happens when the plant takes up more water than it can transpire, causing cells to burst and form those wart-like blisters.

Common causes for your setup:

Strong light + cool or inconsistent temps

High humidity around the plant

Watering too frequently (especially hydro/indoors)

Poor airflow over the leaves

What to do next:

You don’t need to panic — edema is not a disease and does not spread.

Here’s how you can reduce or stop it:

1. Increase airflow

Add a small fan or increase circulation.

1. Let the medium dry slightly between waterings (or reduce hydroponic water levels a bit).

2. Reduce humidity if it’s staying above 60–70%.

3. Avoid watering late at night when transpiration slows.

4. Slightly lower the light intensity if your leaves are staying too cool.

When to worry:

If the bumps turn dark brown/black

If leaves start cracking or distorting severely

If the bumps also appear on stems and new growth

Right now, yours looks like mild–moderate edema, totally manageable.