[Only Ornamental]

Likely so but that doesn't mean you add too much fertiliser, though. See, if you take two well water soluble salts, say AB and CD, and mix them, if the salt AD or CB has a low solubility, that one will fall out and that's the reason why many liquid nutrients come in two or three different bottles. The main salts precipitating from fertilisers are calcium sulfate (gypsum) and different phosphate salts (such as calcium and magnesium phosphate). One could calculate all that but it needs some time and effort and isn't easy if you want precise numbers because solubility is pH and temperature dependent but a rough estimation should be useful enough .
Using chelated calcium can solve the issue but most chelates just switch the calcium with trace elements and you risk to lock these out. On the other hand, there's no feasible magnesium chelate although solubility of magnesium salts at a slightly acidic pH such as present in hydro remains well enough to not pose any issues. A different approach is to "remove" phosphate from the equation as done by using for example polyphosphates. These also complex metals alongside other drawbacks but reduce the tendency to form irreversible deposits. Another strategy, commonly not applicable due high costs, is the use of salts from organically bound phosphate such as your ascorbyl phosphate. If you have no concerns with the added organic material, you could give it a try: let me know how well it works, will you?
Sulphate could be applied in a similar way but sulfate esters (FYI ascorbyl phosphate is a phosphate ester) aren't readily available and/or are either too stable or too reactive (the most frequently used ones at fair costs are either laundry detergents or highly toxic and mutagenic and modify DNA!). If other forms of organic sulfur could be used without causing issues and would be worth the extra costs, I do not know but love to see the results from someone who actually tried it .

[creativeprocess]

Originally Posted by Only Ornamental

Likely so but that doesn't mean you add too much fertiliser, though. See, if you take two well water soluble salts, say AB and CD, and mix them, if the salt AD or CB has a low solubility, that one will fall out and that's the reason why many liquid nutrients come in two or three different bottles. The main salts precipitating from fertilisers are calcium sulfate (gypsum) and different phosphate salts (such as calcium and magnesium phosphate). One could calculate all that but it needs some time and effort and isn't easy if you want precise numbers because solubility is pH and temperature dependent but a rough estimation should be useful enough .
Using chelated calcium can solve the issue but most chelates just switch the calcium with trace elements and you risk to lock these out. On the other hand, there's no feasible magnesium chelate although solubility of magnesium salts at a slightly acidic pH such as present in hydro remains well enough to not pose any issues. A different approach is to "remove" phosphate from the equation as done by using for example polyphosphates. These also complex metals alongside other drawbacks but reduce the tendency to form irreversible deposits. Another strategy, commonly not applicable due high costs, is the use of salts from organically bound phosphate such as your ascorbyl phosphate. If you have no concerns with the added organic material, you could give it a try: let me know how well it works, will you?
Sulphate could be applied in a similar way but sulfate esters (FYI ascorbyl phosphate is a phosphate ester) aren't readily available and/or are either too stable or too reactive (the most frequently used ones at fair costs are either laundry detergents or highly toxic and mutagenic and modify DNA!). If other forms of organic sulfur could be used without causing issues and would be worth the extra costs, I do not know but love to see the results from someone who actually tried it .

I'm no chemist but I do appreciate the info!
So what's the best balance to use for forms of calcium and magnesium?

[Only Ornamental]

Originally Posted by creativeprocess

I'm no chemist but I do appreciate the info!
So what's the best balance to use for forms of calcium and magnesium?

You're welcome.
What do you mean by "balance for forms of Ca and Mg"? Please specify.