As has been pointed out, these symptoms - green veins with yellow between can be caused by either iron or magnesium deficiency however, iron is immobile. The plant cannot move it from old to new leaves so only younger leaves are affected.
Plants can move Mg through the plant system so if Mg is in short supply they take it from older leaves and move to newer leaves so generally Mg deficiency is seen on older leaves while new leaves are relatively normal.
Therefore, first question to properly diagnose these symptoms is whether it occurs on older or newer leaves.
Sometimes it is not really a deficiency of the element that causes the problem. The supply of Mg is reduced in acid conditions so Mg deficiency is seen most when soils are acid low pH). Iron is more available in acid soils but is locked up when soil conditions become alkaline (high pH). Depending on the problem we can sometimes fix it by changing the soil pH to allow the 'locked up' elements to become available to the plants.
I think this is probably not all that applicable to pot culture where supply of trace elements is rather limited. It would be worth Jag's time to check the pH of the potting mix but the problem will almost certainly be solved by applying trace elements and/or changing to 'balanced' fertiliser - something that gives a regular supply of all the trace elements.
Kevin,
Just because you have read something does not actually make it true. The Dynamic lifter info says neutral to slightly alkaline. I have tested several times and get neutral results. Why are you focussed only on the alkaline part of that statement? I think it would take quite a lot to make significant changes to the pH of potting mix but that's justFrom what i have read on AusBonsai many times is Dynamic Lifter can cause considerable more damage to your potting medium than can be beneficial.
Even if it does raise the pH a little, fertilising with any nitrogen fertiliser tends to lower pH so using Dynamic lifter in conjunction with a soluble fert should be beneficial by bringing pH back towards neutral????Dynamic lifter does break down to sludge but, again, you'd need to be using quite a lot to have much impact on a normal, modern potting mix. All organic components of potting mix break down into fine sludge over time. They break down quicker when nutrients, esp nitrogen, is available so using any fertiliser will produce the same results. I also note that some growers make fertiliser cakes from soy meal, etc. These also break down to sludge but we don't see any reference to this causing root rots.
I do use chook poo pellets (not dynamic lifter but a similar product from different company) and cannot find any problems with using it.
your assertion of damage might just be overstating just a little. Just myconsiderable
