I have a similar 13% iron powder and add 1 tsp along with the 1 tsp powdered
trace mix (only has 2.3% Fe) so adding tsp of each I get C & S PMDD with
added calcium into an old 250 ml flourish iron bottle and dose 4 ml daily
for a 40G medium planted/light tank. So if you're only adding iron and no
trace then 1.3 tsp per 250ml or thereabouts should suffice. You will
probably also want to get a potassium supplement depending on growth speed
expectations and a trace mix or more frequent water changes if no trace mix
is added. An iron test kit for the first few weeks to monitor dosage
requirements for YOUR tank would also be recommended.

"Anton Valouev" wrote in message
...
I've bought today can of chelated iron EDTA 13.2 % of iron in a powder.
I was wondering how much of it I should use in the PMDD recepie. All the
recepies I've seen so far add the iron in the form of iron trace elements
liquid, not a powder.

So, I would appreciate if someone could advise me on the amount of
chelated
iron relative to other components that I should use in PMDD.