水草情迷

DEAR ARKI,
DO YOU KNOW WHERE TO BY THE EDTA-FE?
THANK YOU VRY MUCH!

Dear all,
I don't know where can get the EDTA , but the Lab have a lot....
I think can call the lab. supply for one bottle
But we must use AR grade

What is AR grade means ?
Also any source of trace elements mix ?

個網上唔倒

We can buy AR or even industrial grade EDTA in Hong Kong, but the quantity will be big. The best idea is to know someone working in labs or chemical shops to get some 'sample' from them.

may be we can group togather to order EDTA and other chemical for PMDD, so the cost will be cheaper~
BTW i've just got some KNO3 and KCL from Bird Nest, i'll try it out and report the result later
thanks Bird Nest again~~

你地有無 K2O AR ?

I do want to try PMDD two years before, but actually hard to find the sources and the space to store a huge number of chemicals is a headache. A.I. or beginner, if you have some, please sell some to me for try! Thanks a lot........

Arki, Info for PMDD in chinese:
http://www.wxp.ks.edu.tw/aqp/pmddtwn.html

KCL 內經已含有 K20 成份, 一般農業用K2O含量大約值為60%.

A.I., good idea to pull together to buy.

PPMD consists of 2 to 3 major components:
1. KCL, K2SO4, MgSO4, (KNO3 optional) - can be bought easily in HK
2. EDTA-Fe (EDTA + FeSO4) - can be found in Hong Kong
3. Trace Elements mix (Mn, Co, Mo, B, Zn, ....) - not sure if it can be found/ buy in Hong Kong. (some of the Trace elements mix will contain EDTA-Fe already) - but this can be mix by someone who is working in a lab, even school lab.

I think, it is worth to create our own PMDD if we can find 3 together or at least 1 and 2. Else the result may not be very good.

If we only have 1, it can only be a supplement (K+, NO3-) to our existing commerical fertilizers, it cannot replace them complete. We definitely need Fe, else, red plants will not red. Once we get all 3 components, we may not need any commerical liquid fertilzer.

KCL之含量, 其實亦包含了少許微量元數. 僅供各位參考.

Specification 已 post 在圖片區 (我看不到link 的 address, it shows "www.aqugrass.com only, so i can't paste in on this message ar)

DEAR BIRD NEST,
THEY STILL LEAK OF MOST OF THE TRACE ELEMENTS.
PDMM & EDTA-FE & DIY TRACE ELEMENTS STILL A LONG ROAD TO US AR. HOPE EVERY 'SEE HING' ENJOY THEIR DIY PROJECT AND SUCCESS LA.

as i can't find any trace element mix,
i still have to dose my TMG daily in order to ensure there is more than enough trace element in the tank,
otherwise it will be unbalance with the N, P level.

HI ALL 'SEE HING'
I'D GOT SOME EDTA-NA2 & FESO4.7H2O.
ANY SUGGESTION HOW TO MAKE THE EDTA-FE SOLUTION IN A EASIER & SAFER WAY?
THANK YOU VERY MUCH!

Base on the formular information on the link supplied by wwhk,
weight the EDTA-NA and FESO4.7H2O and disolve the EDTA in warm distilled water and add FESO4.7H2O.

Both EDTA-NA2 and FESO4 is not a very toxic compound except in high concerntration. But other heavy metal's CoSO4, ...ZnSO4, will be more toxic.

1g FESO4.7H2O contains 0.2 * 1g = 0.2g Fe
Weight of EDTA-NA2 required for 1g of FESO4.7H2o =0.2 * (372.24 / 277.
= 0.268g

weight of FeSO4.7H20 : EDTA-NA2 = 1 : 1.34

Therefore if you use 10g of FESO4, you need 13.4g of EDTA-NA2