Thanks George.

Glad I didn't buy it then!! Looks like it's the 25kg bag then....

Justin.

"George Pontis" wrote in message
t...
In article , says...
hi all,

I just wanted to ask a question if I could. I have mentioned before that
I
can only find KNO3 in 25Kg bags but when I was up purchasing my trace
element mix for my PMDD I found Sulphate of Ammonia... When i had a look
at
the chemicals on the back, it has 21% Ammonium as Nitrogen and 23%
Sulphate
I have done some research on the net and a chemical website says that
it's
21% Nitrogen and 23% Sulphate as opposed to KNO3, which is 13% Potassium
and
44% K2O (which I gather is 2 Potassium molecules bound to an oxygen
molecule??)... Can I use this as my Nitrogen source? It's in a 2kg bag
and
would be easier than purchasing a 25Kg bag... I have read somewhere that
Ammonium is the preferred source of Nitrogen for plants, so i'm thinking
I
should be safe...

It is not a usable substitute in the aquarium. The ammonium sulphate would
raise
the pH and result in free ammonia in the water. Also, Tom Barr has said
many times
that ammonium is remarkably effective in creating an algae bloom. The one
aquarium
use I know of is to use it as a source of ammonia for fishless cycling.

Also, my trace element composition is a bit different from the one listed
on
the krib, mainly the Fe is 1% lower... Does anyone think I should
compensate for this by putting in some Chelated Iron (which I pick up
from
the local Kmart - a cheaper department store for non-aussies) for
$4.00...?

There is practically nothing that we can control in an aquarium to 1%, and
the
useful concentration of iron is quite broad. The best advice I have heard
about
the amount of iron in the planted aquarium is that one should maintain "a
measureable level". In other words, if you can detect iron with a test kit
then
you have enough. An inexpensive Hagen Fe test kit can easily show iron
below
0.1ppm. The high end of safety is something like .3 ppm, with some saying
even
higher has not be shown to be unsafe.

George