BTW, my stargrass plant is very particular about its nutrients.
I notice white new growth when I have low traces, iron, and/or nitrates.
I also notice the melting of leaves and stems on my M. Umbrosum and Stargrass when the nitrates get low. BGA also -COULD BE- a symptom of low nitrates.
I'm not sure about phosphorus. It seems to me that mainly P drives the uptake of the other nutrients, w/o actually showing a deficiency of itself in my plants. I do notice a decreased uptake when P is short, though. I have also read that GSA will show up when P is low.
People say they see pinholes in leaves when K is short, but I haven't noticed this in my plants. However I think I usually have enough of this and that is why I do not see this particular symptom.
I think Vaughn is right that CO2 really clouds all of these and low co2 could manifest itself in many different ways. From what I see Tom Barr post, low co2 is usually the problem when a plant is not growing well and shows symptoms. This makes sense, as carbon is such a larger percentage of the plant than N, P, or K.
Hope this isnt just obvious stuff that you already know. I dont want to patronize.
Hope it helps.
Good luck with the plants!