Which iron chelate should I use?

[_Maq_]

when I dose phosphate (kh2po4/kno3);

KNO3 is a nitrate. Phosphate (PO4) and iron react into ferric phosphate FePO4, poorly soluble, inaccessible to plants.
I believe, based on indirect evidence, that people often overdose phosphates, and consequently are forced to overdose iron (and use advanced chelates). I'm still only studying this problem. My current pattern is to dose phosphates on the day of the water change, then six days later iron (plus other micros), and then on eighth day water change with dosing phosphates... and so on. Not perfect, probably, definitely not applicable universally. Still under research.

 

[John q]

So this means when I dose phosphate (kh2po4/kno3); i'm actually countering the iron in csm+B. Maybe i should go light on the first two ?

To some extent yes, some of the fe will be lost, however the plants don't really need a lot of iron, probably only a fraction of what we add is actually used/needed by the plants.
At the standard ei level of 3ppm P04: 0.5ppm Fe, or ratios there of, there should still be plenty of iron available to satisfy the majority of plants. If deficiencies do appear (perhaps you have hard water) then add a bit more iron or use an additional chleate.

Is this overdosing? More than likely, or rather adding everything in excess.

 

[anewbie]

To some extent yes, some of the fe will be lost, however the plants don't really need a lot of iron, probably only a fraction of what we add is actually used/needed by the plants.
At the standard ei level of 3ppm P04: 0.5ppm Fe, or ratios there of, there should still be plenty of iron available to satisfy the majority of plants. If deficiencies do appear (perhaps you have hard water) then add a bit more iron or use an additional chleate.

Is this overdosing? More than likely, or rather adding everything in excess.

Actually i intend to have very soft water in all my aquarium 'cept perhaps the one with guppies.