Backyard Aquaponics
A place to discuss aquaponics

A better close up of one of the leaves, and a pic of a different Moringa seedling showing a different sign of deficiency on a leaf from the third branch level (the highest branch level)

I would not worry too much about nitrogen deficiency if your nitrates are 20 ppm you may just be seeing signs of something that is already corrected. Nitrogen deficiency shows on the oldest leaves first and is generally yellowing of the leaves.

The pictures you showed, are all the leaves like that or just the few you took pictures of? If it is just the pictures you showed and all other leaves seem fine, then I wouldn't even worry about it, some small amount of irregularity is quite normal in plants. However, if the whole plant is covered in leaves looking like that, then hopefully some one can recognize the problem because I can't tell quite what it is from those pictures.

Do remember that some problems can be corrected and the leaves may still show the signs. Like when Iron deficiency shows up on my plants, I dose with Iron but the leaves that were already affected, will remain looking off and I have to look at new growth to see that I have fixed the problem.

Do be careful about dosing too much with different nutrients as an overdose of something can be just as bad if not worse than a deficiency.

Oh and you mentioned something about infinite nitrates. Well I wouldn't go that far, really high nitrates can be bad, it is just that we don't usually have to worry too much about them in our systems since the plants use nitrates. However nitrates over 500 or 1000 ppm long term are not really good for fish and could probably cause some issues with plants too.

Sorry I do not know how much of the potassium nitrate that one should use since my system has plenty of nitrates I've never gone looking for that answer.

You'd also find that any purchase of Potassium Nitrate will attract the attention of the "men in black"...

Hey confuzedd,
That looks like an old leaf.
Take a pic of the new ones they are the ones you need to be interested in.
Old leaves are a store of energy for a plant, mostly they will die off as the life is taken from them.

I don't think SaltPeter is that heavily scrutinised? Ammonium nitrate on the other hand...

Some time ago, I went into a large hardware store to buy some (about 1kg) ammonium nitrate as it was recommended to me for my fruit trees. I was told by the sales-staff it is considered almost as a controlled substance as it can be used in the manufacture of powerful explosives, I might be asked to provide identification at the checkout... and the smallest bag they could sell me was 25kg!

Small amounts of potassium nitrate is fun to play with; making rocket motors, smudge pots, smoke bombs... and of course gun-powder!



Scott

If your saying the yellow leaves are the newer ones, and the older leaves are staying a nice lush green, then you have a sulphur deficiency

If its the older leaves that are going yellow and getting spotty then you have a magnesium deficiency

Both deficiencies are pretty rare... and are easily mis-read as lockout of phosphorus or iron... and sometimes maganese.... usually around pH 8.0 - 8.4

Agreed to an extent,

The picture of the moringa is a classic for bad ph, with the vein being yellow compared to the green of the leaf, however the pictures are representitive of those deficiencys I mention but are also not limited to just them, whether it be ph thats causing the deficiency or the lack of the nutrient is an unknown

Sorry, but at pH 8.0, potassium, calcium, sulphur and magnesium are fully available for plant uptake...

If you're "fishless" cycling then perhaps add some Seasol or Maxicrop or "rock dust" ... to provide the trace elements...

If you're using "humonia" to cycle... and you think your plants might be deficient of any of those trace elements... then as above... but I'd also suggest getting a medical check up and reviewing your diet...

Hmm, ok so my pH is 7.6<8.0 ; Probably 7.9

I forgot to mention that I still haven't bought a reflector yet as I'm growing indoors. Maybe the plant's photosynthesis isn't working optimally since... ummm.... maybe the wavelengths are deficient??

Okay, not wanting to get into a debate about whos right or wrong, but I simply quoted what I see, have been doing hydroponics for over 20 years. The plants are typical of the two problems I mentioned, but that does not mean this is the problem, one needs to test the soil or water. Also whether they be deficient from lack of nutrient via ph or no trace element, only testing the water will tell.

On another note, the chart you supplied is a soil ph chart and not hydropnics ph chart and yes they are different,

Here is another pic showing all 4 moringa babies at 1 month old. The tallest one is about 1 foot high.

They look lanky. I got MH lights too -- not HPS. hmm like I mentioned earlier, maybe its got to do with not having any reflectors.

Thats a lot different than the close up picture you supplied, put them in the sun they are starving and dying, definetly lack of photsynthesis

Actually Simso... no it's not... it's the standard chart of pH nutrient uptake that's utilised in hydroponics... as well as in soil based systems...

There are other charts... ( I could post several)... with very minor variations... but they're all essentially the same...

Nutrient uptake is dependant on pH... not on the media in which plants are grown... unless it alters the pH...

And the research that underpins the chart is what led to the understanding that hydroponics, particularly NFT could be successfully employed.... without media...

And the reasoning behind the fact that hydroponic systems are adjusted to run at a pH between 6.4 - 6.8...