Ei dosing (from aquariumplantfood.com) ive subtracted the magnesium sulfate from the recipe as were have moderately hard water from tap 10gkh. It seems that the recipe is quite heavy on the magnesium sulfate, 6 teaspoons per 500ml mix.
Is this consistent with some sort of nutrient deficiency?
I agree with "@xim", it looks like mechanical damage for me as well.But anyway, the picture doesn't look like magnesium deficiency. It looks more like mechanical damage to me.
Ei dosing (from aquariumplantfood.com) ive subtracted the magnesium sulfate from the recipe as were have moderately hard water from tap 10gkh.
"@Ian_m" is right it will probably all be calcium, you are unlikely to have much magnesium in your tap supply in most of the UK . It is to do with the environment in which the <"limestones, that form most of our aquifers",> were laid down in.Most of UK water is from carboniferous sources thus is hardened by calcium carbonate and not any magnesium source.
Mg deficiency symptoms can appear similar to iron, pale/white/yellow leaves. In fact Mg deficiency can prevent uptake of iron, leading you down the path of thinking you have iron deficiency. If Mg is added leaves will generally recover as unlike iron Mg is mobile in the plant.
You can get soils which are both alkaline and base rich, but will grow heathers etc if that base is <"magnesium rather than calcium">. It is more that high calcium levels interfere with the uptake of both iron (Fe+++) and magnesium (Mg++) ions.I was under the impression that excess magnesium can prevent the uptake of iron in plants?