Iron Chelate vs Iron Sulfate

[EdTLawn]

I am able to find 7% iron chelate and 21% iron sulfate locally. Which is the better of the two for greening of lawns ? Iron sulfate is also 3-4 times cheaper as well.

I read that chelate is faster in greening, but less duration than sulfate.

[cgaengineer]

Iron sulfate is really for killing moss. I have tried sulphate and did not experience any noticeable green-up.