Backyard Aquaponics
A place to discuss aquaponics

Once again Mantis this a great link, on the next session he covers how to calculate how much chelated iron to add. and how often to add it.

Also heres a few bits I cut from other sites


From Searls MSDS sheets there's is Fe EDTA

12. ECOLOGICAL INFORMATION
Ecotoxicity - Avoid contaminating waterways.
Persistence/degradability and - Not readily biodegradable. (1)
Product Name: YATES CHELATED IRON Issued: 05/07/2010
Substance No: 000000020597 Version: 2
Page 3 of 4

from US web site cant remember name.

Iron chelates. Chelates are compounds that stabilize metal ions (in this case - iron) and protect them from oxidation and precipitation. Iron chelates consist of three components:

Fe3+ ions
A complex, such as EDTA, DTPA, EDDHA, amino acids, humic-fluivic acids, citrate.
Sodium (Na+) or ammonium (NH4+) ions
Different chelates hold iron ions in different strengths at different pH levels. They also defer in their susceptibility to iron replacement by competitive ions. For example, at high concentrations, calcium or magnesium ions may replace the chelated metal ion.

Fe-EDTA - This iron chelate is stable at pH below 6.0. Above pH of 6.5, nearly 50% of the iron is unavailable. Therefore this chelate is ineffective in alkaline soils. This chelate also has high affinity to calcium, so it is advised not to use it in calcium-rich soils or water.
Note that EDTA is a very stable chelate of micro-elements, other than iron, even in high pH levels.

Fe-DTPA - this iron chelate is stable in pH levels of up to 7.0, and is not as susceptible to iron replacement by calcium.

Fe-EDDHA - this chelate is stable at pH levels as high as 11.0, but it is also the most expensive iron chelate available.

5000 gal pond?

Yes this stuff is expensive. 1kg for AU $45 over here.

from the sums I could need 220g every 3 weeks!

Be great if there was an easier (cheaper) way, especially here in Oz where half the country is Iron!

I do find it hard to believe that the average back yard AP system would need iron added every three weeks. My 1st system ran for 2 years before I added any mineral sups. and I have pulled a lot of nice green vegies out of it the whole time.

Its only been looking deficient over the past 2-3 months, I've recently added a few mineral Sups. Including Iron chelates and everything seems to be greening up again. I don't think I'll add any more until it looks like it needs it.

I guess in a large scale system with a high amount of plant production things would be different.

I purchased some EDDHA from the Greenfingers site linked to earlier in the thread, as I have ph around 8. It was red, so red the tank looked like someone had been murdered in it.

I've still got over 50% of both the chelated Iron, and EcoRose that I purchased when I first started my systems... years ago...

And I've probably only used about a twin pack (2 x 2L) of Seasol each year...

if you are concerned about the iron levels in your water, consider using an aquarium iron test kit. like Rupert i dont use a lot of iron supplements (we are also on rain water so no iron in the top up water) and when i tested the water i had more iron than was needed for the plants. this was after a season of growth.
as there are so many variables, i would suggest testing rather than guessing, or wait for signs of iron deficiency in the plants befor adding any supplements

i bought an iron test and it doesnt show any iron even when i tried it in some seperate water that I added a little iron chelate to...hmmm

I had the same result and then re-checked the amount needed and found I'd overdosed

I'm hoping the Feeder fish don't rust. LOL


Here's the correct amount:
http://www.youtube.com/watch?v=qczagOJG5mI


Joe

EDTA toxic?
any link to the above info?

the big "POISON"

on the jar was the give-away to me!

but how about "Yates trace elements"

So where is everyone in Australia buying their Fe DTPA from.. i couldnt see it an of the bunnings, nurseries or hydro stores that I went to today?

I got mine from these guys $45 / kg


http://www.greenfingers.com.au/store/?4 ... -1kilo-box

added 150g of EDDHA dissolved into a bucket of water and tipped into the 8.5kl pond.

the neighbours are going to think I have murdered somebody!

hope the fish don't mind.