I got a couple of people asking about the iron/trace element mixture that
I make and I thaught that I had better put it up and see what people
think of it.
As to background, it is a modification of trace element stocks that are
used in plant tissue culture. Just about every plant that has ever been
tried will grow on Murashige and Skooge (MS) media. Recently is has been
used to grow Cryptocoryne's to maintain an endangered species, Annubias
barteri var have also been grown on this medium. The liquid form will
also grow Ottelia alismoides in a growth room here.
Ok to the recipe
For 500ml of 10,000 times stock you need
a trace of Na2MoO4.2H2O
and 7.4g of Na2EDTA (I add it as a .5M stock at pH8) EDTA does not like
to dissolve in acidic media and that it is why I make a concentrate.
The actual dose rate depends on the iron content of your tank, and should
always be used in conjunction with an iron test kit. (which incidently is
only Potassium thiocyanate and sulphuric acid). At 10,000 dilution this
gives a concentration of .5ppm.
The water here is very soft with a calcium hardness of only 20ppm.
Nitrates have not been measured, but we are high in the mountains (well
for Australia anyway) and centered in a large area of National park, so
my guess is that the levels are pretty low. I make the hardness up in my
tank with a propriety product that has Ca, Mg, K, Na etc. The fish that I
keep are almost entirely rainbowfish with a few ancistris and corydoras
The plants that I keep are a variety of swords (5sp), cryptocorynes (12sp),
hygro, ambulia, java fern, thai fern (this one I do not know what the
scientific name is), aponogetons (4sp), and "ammania".
An alternative is to get the Iron fertiliser that is at your garden
centre and correct the amounts for the purity of the chelate. Some of
these have clay in them as a carrier, just let it sit a day or two and
you will not have to bother about the clay. I have a friend that is doing
this and the results are pretty good. Caution does need to be exercised
with this option because some "trace element" mixtures may have nitrate
in them etc, so if you do this make sure that it is a straight iron
chelate and not a trace mixture.
Hope this helps some people