Backyard Aquaponics
A place to discuss aquaponics

Probably contributing next to nothing in this thread but a few things I recently noticed in my system. Bear in mind that I'm running extremely low density fish - 3 goldfish/ 3 plecos in a 150G tank supplying roughly 6 sq. ft of 3/4" pea stone media bed.

I try to keep my pH between 6 and 7 and it takes about a month for it to start bottoming out. When it hits 6 I toss the nylon stocking full of oyster shell in under the gb water intake and start monitoring after about a week.

My toms were showing the same kind of yellowing especially in the lower leaves. Threw some chelated iron in and about a week later started seeing great results. The pH is right around 6.8 at the moment.

Such being the case, the shell sock came out tonight. When it did, I noticed that the nearby toms had actually found there way up and grew into the sock. I take that to indicate that they're looking for even greater amounts of calcium than they're getting flowing through the system.

Not having yet grown peppers, whether tomatoes and peppers require similar nute levels I'm not yet sure so hopefully this isn't just taking up space on the internet unnecessarily...

I don't know that you can test for Magnesium deficiency, other than a leave tissue analysis at a lab. You could possibly test the water, or have it tested, but there is no real point IMO, as it can be easily rectified once deficiency symptoms begin appearing, the first of which will normally be yellowing between the veins on older, lower growth. As the chlorosis develops it may result in the yellow interveinal patches dying and becoming necrotic (dead) and the yellowing may also progress to the veins.

As mentioned before, you can use Epsom salts, or you can also use Dolomite Lime, but I have no experience with that in AP so couldn't suggest a rate. Bear in mind, Dolomite lime will increase the pH, so shouldn't be used if your pH is in the 7's or higher.

You can use Dolomite... just sprinkle it around the affected plants.. on the grow bed surface...

Calcium deficiency is pretty common in ground grown chilli's.

Cant imagine why tomatoes would be too different.

My Toms are going great guns with no sign of deficiency,the next barrel had the chillies in didn’t very well at all. Could it be Mg deficiency ?

PH?
Stick a banana under neath one

PH stuck bang on 7 has been for weeks,the banana skins go in regularly my 9 month daughter loves the small sweet bananas we have here,so i put the skins in the bed.not all of them just some.

Jay, how do you do this? Under the grow bed? Or, directly in the fish tank?

In the grow bed,just bury them in the media.

I am confused now because you are the expert on plants and I could be wrong
On the first glance looking at the leaves, necrosis in the interveinal spaces between the main veins, I thought it would be combination of Potassium/sodium and/or Magnesium deficiencies combined with a mild fungal attack.

Thanks Mr. Damage, I'll add Epsom Salts today, I won't see an instant increase in the fish solids will I

Thanks Rupe, I tried Dolomite Lime around the root area of my Tomatoes and Chilli plants but very sparingly because of my pH at 7.6 I didn't want increase it any, and I think the small doses I used were just too small and a waist of time. I used 1/2 teaspoon on each plant and they did pick up very, very slightly at that dose.

The pH didn't rise so I don't know if small doses of Dolomite Lime at regular intervals would help without raising the pH but I'll now try the Epsom Salts and let you both know how it goes.

Again thank you both for your advise

By listening to others Nanniode - I'm reading your threads and your learning some things but others not.
Yes directly in the growbed as stated. I heard it from Charlie.
I'm trialing fresh banana vs already rotted banana.
I've also put one tomato plant on top of a banana with a handful of dolomite lime in my dirt garden.

Hey Joblowbanana,

Off topic:
I followed this advice but also put some in my sump - Just remembered that my river pebble brown water cleared up - maybe the fine particles helped.

I also found a PH change when doing this but I don't think ontop of the growbed is an issue with dolomite - it's pretty light compared to garden or hydrated lime.

Thanks Jayendra, I certainly don't want a rise in pH.