Deficiency

[Hufsa]

It’s suggesting 1.48g of 13% EDTA Mn in a 500ml stock solution to achieve 0.25ppm in a 270 litre system, dosing 25ml per day, 7 days per week. Does that seem right?

Did you subtract the 0.1 ppm that you get from the existing micro mix?

 

[hypnogogia]

Did you subtract the 0.1 ppm that you get from the existing micro mix?

No, I hadn’t. Was just wanting to check if that seemed right for 0.25. If I subtract the 0.1 I already get, then I only need to add 0.89g.

 

[Hufsa]

Yes that seems correct on my end as well
Try at least a few weeks with a weekly total of 0.25 ppm Mn combined from your two sources, if it is what your frogbit is lacking then the response should be quite clear 🙂 Fingers crossed

 

[Hanuman]

It’s suggesting 1.48g of 13% EDTA Mn in a 500ml stock solution to achieve 0.25ppm in a 270 litre system, dosing 25ml per day, 7 days per week. Does that seem right?

I confirm the calculator is giving you the correct answer.

 

[_Maq_]

Do you believe that plants roots can access and use these nutrients once precipitated? And do you think there's a chance that this precipitate could lead to toxicities?

Definitely so. Unlike within filter, in the substrate the redox is much lower and some precipitates dissolve. Beside that, plants can help it by exuding specific chemicals into their rhizosphere. And even if plants can't reach these nutrients, bacteria can, and bacteria will keep nutrients cycling. Organic vs. anorganic, precipitated vs. dissolved - nothing is stable for very long.
Toxicity? Ah yes, it may very well happen if oxygen level in the water column gets too low, or perhaps, significantly lower than before.

 

[Happi]

Fe 0.5
Mn 0.1

Maq has given a very good answer and IMO these two Nutrients are Prone to Precipitation from many factors, such as water chemistry and Filtration. some of us try to maintain the 2:1 Fe:Mn ratio considering some of these factors, IME even 1:1 Ratio works well.

if the ratio become 5:1 or this gap becomes Wider, then you will start to see what looks like an Fe Deficiency, but truly you are seeing Mn Deficiency. This is why some people when they add more of something, they are just correcting the limiting factor which was previously limiting to begin with.