Backyard Aquaponics
A place to discuss aquaponics

Hey guys,

My system is about 2-3 months old now. Up till now i have had no problems and plants and fish have been happy. Recently i pruned back my tomato plants and now all my tomato plants have started to have there leaves dry up and die.

Just today however i noticed some pretty serious yellowing on my cucumber plant and some light yellowing on my capsicum plants. one tomato plant has been growing fruit for about 1-2 weeks and today we spotted our first baby cuke and flower buds on our capsicums.

Photos are attached below of the plants if anyone has any ideas as i'm a complete newbie gardener.

My system is approx 1300L of water, i add a cap full of seasol weekly, i currently have 14 silver perch, on Saturday i removed 6 goldfish and today i added 15 more SP fingerlings.

PH: 7.4
Am: 0
Nio: 20
No3: 10-20

Historically the system has been running with No3 of 40-80

more photos

Perhaps some chelated iron needs to be added.

AussieAnzac,
For such a young system, it's a bit aggressive to try and grow heavy nutrient feeders(cucumbers and tomatoes) - usually it takes some time for the system to mature enough to free up the nutrients required to grow those types of veggies. As arbe has pointed out, you will need to add some chelated iron as the pictures show iron deficiency (the yellowing between the green colored veins in the leaves). In addition, you are most likely deficient in calcium/potassium due to the heavy feeders as well as less availability at 7.4 pH (try and shoot for 6.4-6.7 for best nutrient availability)

Hope that helps!

I think this might actually be a magnesium deficiency. The tops look OK on some of the plants indicating that the deficiency is in a mobile element. If it were Iron, the top would be lighter color and the base would be darker instead of the other way around. A spray application of epsom salts should take care of it.

Epsom Salts - MgSO4 - A teaspoon of Epsom salts per 1000L or a smaller foliar dose 375g to 20 litres - from the product label Faulding Epsom Salts. 1 tsp per gallon for spray or 1 T per gallon in soil drench (for regular gardening). Do not over apply and don't use on bright sunny days - this can cause leaf scorch.

scotty,
Good catch! It's usually a iron deficiency for starting systems but you are right about the upper section of the plants looking good while the bottoms show deficiency.

AussieAnzac,
Are you getting any fruit from your tomatoes or cukes?

My cucumbers did something similar, leaves just kept going yellow and dieing. eventually the plants just died. Maybe it is a similar problem, new system? Mine is only three months old. Though my tomatoes and capsicums are looking good and have fruit.

I figure from all the advice I have read on here, while it is all new and ph is still high, I would have issues and failures.