Backyard Aquaponics
A place to discuss aquaponics

Hi, I set up my IBC aquaponics two months ago, I planted strawberries, kale, wild strawberries, letuce, cauliflower and some garlic. I have a few carps around 1 kg.

Two weeks ago leaves of strawberries started to go yellow and red at edges (pictures).
I thought it is deficiency of Iron, added Iron chelate a week ago but without any positive effect.

Do you think it might be potassium deficiency?
I would appreciate your help.

BTW, sorry for my English, I hope you'll understand

Regards,
Chris

Looks like a combination of Iron and either Phophorus or Potassium deficiencies Chris. The yellowing on the new leaves is the Iron and the red around the edges on the older leaves is the Phosphorus or Potassium. Usually with phosphorus growth will be a bit stunted but the red color is more typical of this so I'm not sure which it is.

What's the system water pH at? What type of chelated iron did you get? Try using the iron chelate as a spray the pH matter less done this way. There's probably some info on the bottle about the dose. Here's some additional info for Fe-DTPA if this is what you used (this is what most use and I figure you could compare with the dose you used earlier) -

Chelated Iron - 1 level teaspoon per 1000L every 6 to 8 weeks if pH is above 7.0 and iron deficiency is indicated. Fe-DTPA is light sensitive probably best to apply just before dark (about 96 hours for >90% of Fe-DTPA to be destroyed with exposure to light of the wrong wavelength - usually precipitates out and becomes unavailable to the plants).

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Probably the easiest way to cure all of these is to sprinkle some Blood and Bone (50g/1000L of grow bed applied to the media, not the plants directly) on the grow bed but that won't tell you for certain what the deficiency is. Other options that might help you figure out what's going on -

Maxicrop or Seasol contain potassium so they would help if it's a potassium deficiency.

Bone meal alone - this would help if the deficiency is Phosphorus but the pH has to be below 7 for this to work well. The same is true for rock phosphate.

Cheers

I would be more worried about the light color of the new growth.

My strawberry leaves turn yellow and red after a while. Pull them off and keep moving.

@Krzysztof - Hi, take a look at the link below a lot of information on plants.
viewtopic.php?f=3&t=25056

Regards