Backyard Aquaponics
A place to discuss aquaponics

Been getting white leaves on brassicas and parsley plants and hoping someone knows what is happening
PH of this system is 7 with 8 cod eating well

Look like they are dying Mantis

Got basil, celery and silverbeet in the same system all nice and green

looks like Iron Chlorosis

Maybe to early in the season for brassicas?
I know B is selling them atm, but i thnk it's to early.

Googling iron chlorosis I think you may be right. I did think along these lines today and added some chelated iron and seasol. Tommorow I will pull the shellgrit sock out of the tank to lower the ph a bit

Went out tonight looking for pests and found that some of the leaves on these plants look a bit whiteish (new word) and found the the whiteish wipes off, so its a fungus

Ecorose spray coming out tomorrow big time

Seedlings are even dying off

I don't think it's Iron. Iron deficiency symptoms will show up in the newer growth first, your newer growth looks fine on the broccoli... I'd put my money on Potassium.

The white patches on the broccoli, are they just white, or are they necrotic?

Also, it looks like you'd sprayed the plants with something before taking the pic, what have you been spraying on them?

are you sure you dont have bugs

Only sprayed with dipel. Hit them all with eco rose this morning as well as putting some in the system

the whiteish stuff it is powdery mildew, well known fungus on brassica, I can suggest to buy mildew resistant seed! I do not know about eco rose, but here we use sulphur burner if you have them in a GH. (it's the only mildew organic threatment as I know of)
I think I've heard of some folks using bicarbonate diluted in water and spraied on the leaves, further research needed on this methods.

PS: in UK we get loads of fungus problem, wet country!

Is it too hot there for broccoli right now, like Lyndon346 says? The plant looks like several things going on, lots of bug feeding. The white patches are only in between the leaf veins so I don't think it is powdery mildew. The plant is maybe not happy and so everything is going wrong at once. It also looks from the hose water that the water line for flood may be high for that bed?

The parsley looks potassium to me too.

(I'm slowly learning about plant diagnostics in the class I'm taking so this is good practice and learning opportunity thanks Mantis!)

It could be powdery mildew... but powdery mildew is much more likely to affect cucurbits... than brassicas....

But when it does affect brassicas... it looks different than when it affects cucurbits....

If it is powdery mildew lowering the water level in that bed might help. It likes hot dry days and cool moist nights.

I got this from the director of the class I'm taking:
"When it comes to diagnosing vegetables, particularly seedlings, you always want to look at the new growth. Many things can effect the first leaves. If you look closely, the newest leaves look great. I would let them grow and trim the others in time. It's really tricky to get the fertilizer just right in aquaculture systems. That's my 2 cents worth. It's really a guess when you don't know the whole story."

This might be worth a look...

http://5e.plantphys.net/printer.php?ch=5&id=289

Although nothing stands out as your problem.

Are you adding acid to your topup water by any chance? I saw something similar due to an accidental double dose of acid. I'm not sure if it was directly because of the acid, or because of nutrient lockout due to a wacky pH, but my parsley in particular looked just like those leaves.