水草情迷

If you want to create the same concerntration of Fe as in the PMDD formula in thekrib's site,

you need 1.015 / 0.2 = 5g of FeSO4.7H20 and 6.7g of EDTA dissolve into 500ml of warm distilled water.

Base on the the recommended concerntration of PMDD from the Krib's site
Distilled warm water = 500ml
FeSO4.7H20 = 5g
EDTA.NA2 = 6.7g
you may also add the followings to the same solution
K2SO4 = 41g
MgSO4.7H20 = 15.5g


You may increase (double) the Fe contain if you plants require more Iron, but make sure to increase the weight of EDTA.

dear Alex,
thank you very much for your information, if the amount of chemicals are not very accure, what will happen?
last night i made my 1st try, the solution made was pale green color with little ppt. are they ok.?
thanks for advise.

Pale green is good indication as Fe2+ is green and Fe3+ is brown. Plants perfers Fe2+ rathar than Fe3+. The PPT is the Fe ions, try to add more EDTA.

I don't think it will be a big problem if the amount is not accurate as Fe and EDTA are not very toxic. But suggest you to use excessive EDTA than FeSO4. Firstly it will be less ppt, Secondly the excessive EDTA can bond with other heavy metal ion to reduce the toxicity, which is no harm.

What was the ratio of FeSO4 to EDTA you are using last night ?

dear alex, thanks for reply,
i use: 3g fe + 4g na2-edta to one liter volume.
thanks.

hi all 'see hing'
does anyone use BASF 10-4-7 fertilizers (for flowers)
composition:
10%N, 4%P2O5, 7%K2O, 0.02 PPM MGO, 0.7%S, 17PPM MN, 140PPM FE, 25 PPM CU, 5 PPM ZN, 22PPM B, 3 PPM MO.
PLEASE GIVE ME SOME ADVISE OF DOSING.
THANKS ALOT.

DEAR ALLSEE HING,
FE+ TEST RESULT REPORT, 30ML DIY EDTA-FE AFTER 1 DAY
CHELATED IRON 2MG/L
NON-CHELATED IRON 0MG/L (NO READING)
SEEMS IT WORK WOR!
THANKS FOR INFORMATIONS PROVIDED BY ALL SEE HING & SUPER HING!

beginner: what method did u used to 分別 test out the concentration of the chelated and non-chelated iron?

DEAR ARKI,
I USE HAGEN TEST KIT, FOR CHELATED & NON-CHELATED IRON CAN BE TESTED.

Dear Beginner,

Base on the concerntration of your PMDD and the quantity of PMDD you add to you tank, The actual weight of Fe.EDTA added to your tank be 30 / 1000 * 3g = 90 mg of Fe.EDTA OR 90 * 0.2 = 18mg of Fe2+

Is the testing kit measure the concerntration of Fe.EDTA or Fe2+ only? If it is 2mg/L of Fe.EDTA, the size of your tank
is projected to be 90 (mg) / 2 (mg/l) = 45 Litre
How big is your tank ?

dear alex,
i think they means chelated iron is fe2+, but not very sure.
my tank is 36"

DEAR ALEX,
I READ THE USER GUIDE AGAIN, I THINK THE RESULT OF 2MG/L OF CHELATED IRON CONSISTS OF:
FE-NA-DETA & FE2-EDTA ALSO.