Yep I believe you are correct with that.
@Jimster @Dirtbag was talking cal carbonate directly binding with P and forming cal phosphate which is mostly insoluble and will precipitate out of the mix. This can happen when the PH gets to right around 8 which is why you have to be careful using the carbonate version in nutrient mixes. Kind of like when using MAP. You have to specifically make a separate application of it or mix it in its own step cause it doesnt like to play nice with other nutes (even tho its one of the best forms of P to use as far as uptake goes but that nute in itself can have all sorts of effects since it contains NH4 - article below)
Exactly
there is 2 parts to that
Calmg (Cal N version) usually have Fe in them (since they are for tomatoes to prevent blossom end rot) Problem is it can start locking out P and will make it look like a deficiency.
Calmg (carbonate) can have the effect as above and basically bind the little available P and will cause a deficiency.
N and it's uptake, depending on the form, is what swings medium PH both directions in the root zone directly effecting all sorts of things. PH being one of them so
Calmg (Cal N version) can swing the medium PH out of wack. Good read
In this article, we are going to look specifically at the effect of the ammonium/nitrate ratio and its effect on the growth and development. Read more >
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