Backyard Aquaponics
A place to discuss aquaponics

In this particular bed I have about 5 tomato plants of various varieties.

2 of the plants I purchased as seedlings from Bunnings. The others I grew from seed.

The 2 from Bunnings have developed black spots or patches on the leaves. The rest of the plants are fine.

It has taken about 2 weeks for the black spots to appear.

Any idea what could be causing this?

seems to be a fungus or some disease... is your water level in GB very close to the top also.. how often Is the leaves getting wet from above.. also what is your nitrates readings.?

Water level is below the surface by a few centimetres.

Wet season up here but the other tomato plants are fine.

No idea about my nitrate level but the system is thriving and fish are healthy and eating well.

it could definitely be a fungus.. tomatoes don't like getting wet on their foliage nor do they like moist environments.

+1 keep water off the leaves as much as possible.