EDTA or DTPA Iron Dosing? What's the difference?

[Allan Asis]

Hi folks,

What's the difference between EDTA and DTPA iron? This from lushgro powder micro Rexolin E13 http://www.ecocityhydroponics.com/rexolin-e13.html and D11 http://www.ecocityhydroponics.com/lu...xolin-d11.html.
Any advantage on which one for planted tanks dosing EI?

Also, what should I replace Seachem Trace with Lushgro product line? All micros - Lushgro Micros Liquid http://www.ecocityhydroponics.com/lu...os-liquid.html and Rexolin APN http://www.ecocityhydroponics.com/rexolin-apn.html contains iron already it seems. Although the iron content seems to be very low if I were following EI dosing. If my math is correct, I will end up emptying the 100mL bottle in a matter of weeks If I keep up with recommended EI dosing. So what do you guys do usually? Use APN or Lushgro Micros Liquid for other micronutrient and add EDTA/DTPA iron to meet EI dosage?

Also, any idea how do I calculate the ppms for APN liquid? In website, it's based on %. I have no idea how to relate it in grams/milligrams.

Many thanks!

[Xiaozhuang]

If you have more alkaline water (higher KH), use DTPA as the bonds last longer. If you have neutral acidic water then EDTA will do just fine. Alternatively you can also mix the two. Even if you use EDTA in alkaline water, say KH 8-12 - it will remain in circulation for a couple of days - it just means you need to dose more frequently.

I do use EI, but I use CSM + B which I buy from overseas... a couple packets will last years even if you dose heavily over multiple tanks.

To calculate from % you need to convert it using atomic weights from the periodic table of elements, then with a micro-scale, weigh it against the weight of water in your tank

[Allan Asis]

If you have more alkaline water (higher KH), use DTPA as the bonds last longer. If you have neutral acidic water then EDTA will do just fine. Alternatively you can also mix the two. Even if you use EDTA in alkaline water, say KH 8-12 - it will remain in circulation for a couple of days - it just means you need to dose more frequently.

I do use EI, but I use CSM + B which I buy from overseas... a couple packets will last years even if you dose heavily over multiple tanks.

To calculate from % you need to convert it using atomic weights from the periodic table of elements, then with a micro-scale, weigh it against the weight of water in your tank

Thanks XiaoZhuang. So DTPA is the best choice regardless of water alkalinity, but if your water is acidic (like mine 5.5 - 6), EDTA will do as well.

I cannot find a supplier of CSM+B in Singapore Is this a controlled substance here? Where do you order yours? Or do you buy them overseas personally?
I also checked 2 online suppliers http://greenleafaquariums.com/ and http://nilocg.com/ but unfortunately they don't ship these items in Singapore, at least when I check the shipping availability in their website.

Calculating through atomic weights seems like a lot of work, meaning I am likely to end up making mistakes in the process. I'm no good at chemistry lol!
But right now, it seems that's my only option. Dr. Mallick does not sell Rexolin APN powder unfortunately
The Lushgro Micros Liquid is also very expensive if used following EI, so I better just stick to Seachem Iron/Trace for that.

[Xiaozhuang]

CSM + B is not controlled, but you can't get it here. I'm sure nilocg ships it to SG if you message him... you can find him on fb it's just a matter of price. Alternatively, sites like aquariumfertilizer.com does ship to SG for sure, I think I bought mine from there.