Backyard Aquaponics
A place to discuss aquaponics

Hey All,

I am having some issues with tomatoes and lettuce. They started off with small black spots on them and have grown larger causing the leaves to turn yellow/brown. The lettuce has gotten out of control. Does anyone have any idea what could be causing this? I am wondering if my water levels are too high and have caused mold/fungis (I live in a very humid part of Texas) or if the plants are not getting the proper nutrients.

My ph levels have always been high...around 8.2 so I am not sure if this has caused the plants not to be able to absorb much nutrients. I use chelated iron as needed and I have buried crushed egg shells for calcium.

If anyone has any ideas for what may be causing this or how to fix it, I would appreciate any input. I have attached pictures as well. My water level readings are as follows:

Ph- 8.2
Ammonia- 0 ppm
Nitrite- 0 ppm
Nitrate - 40 ppm

Thanks!

Not sure what's going on, thought I better bump this up. It looks like aphids might be present and possibly some spider mites near the base of the lettuce but mold is probably the main issue. Check if you have water splashing on these plants and prevent it.

What's your weather like?

Any spotting of the tomato plants higher up?

Not long before your thread we had another with tomato problems that looked similar but I couldn't find it. Maybe someone else can point this one out or knows what's going on..

blackspot?

get a fan and turn it on high, point it at plants

it sure looks like a fungal issue, which can be solved by robbing the fungus of one or more of its feeds

increased air flow or lower humidity should help

/standard disclaimer proclaiming immense ignorance applies/

Thanks for the input on this! I live in Houston, Tx so the humidity is typically 95% or higher in the spring/summer (miserable) which would definitely leave the plants open to mold/fungus issues. Removing the humidity will be impossible unless I move the system inside......the wife will definitely not go for this. I will have to try the fan and see if that helps at all.

I do have some spots that are beginning to appear higher up on the plant - it has reached the second tier of the leaves. Could that be septoria?

Main reason I asked about the spotting being higher up was to check on splashing. I can't really tell you for certain what this is (unless I have a microscope, then maybe).

I am having the same problems on my pepper and tomato plants right now. Leaves are blackening at an alarming rate. The scary thing is, it's not even close to our wet season yet. I've been trying to pick off the leaves as the spots appear, but I have pretty much picked my largest tomato plant back to a stick in comparison to what it used to be. Just not the best green thumb here.

Also the Ph sounds high I would slowly reduce it to around 6.8-7.5 over the next 2-3 weeks.


~Jtk07

What type of rock is in your gb ?

Maybe look at lowering the max water height in the gb also. Once the plants have long enough roots the water could be lower. If the water it unnecessarily high it will cause the top rocks to be wet and evap water causing humidity for the fungus to grow.
If you lower the water level an inch at a time and you notice lack of water signs look at your pump cycle times to counter that problem.
jim

Any luck on the spots disappearing? I have been having to continue with the chopping off of leaves and stems. My culantro plant is pretty much gone. It looks like I might have to yank it completely. It has slowed down on my large tomato plant, but seems to claim a leaf every few days.