Update on no iron showing up

Note to the mailing list, George and I have had a running dialog on
my problems with getting an iron reading from my show tank. Since the
information that I am collecting might be of more general value I am
going to copy my data and observations to the list.

	Just a quick update on what my latest tests seem to show. I decided
to see tonight if it is the water or environment that might be causing 
the problem I am having not seeing iron. The test are still not conclusive,
but do show a trend. 

All tests were done using a ~2 liter sample of water at ~82F. I was using
ferro vit to generate the iron and using the Red Sea iron test kit.

Test						Results
Plain tap water (control)			0ppm 
Plain tap water (0.5ml dose)			~0.01ppm (minimal reading) 
Plain tap water (2ml dose)			0.1ppm 
Tank water (control)				~0.05ppm (some reading but
						under the bottom of the scale)
Tank water (2ml dose)				~0.1-0.2ppm 
Plain tap water - PO4				0ppm

It doesn't seem that there is anything in the tank water that acts different
then plain tap water. However, to get a reading of ~0.1ppm I am adding
a significantly higher dose then recommended on the bottle. The ferro vit
recommends 2.5ml/10l of water. I am adding it at ~10ml/10l which is 5 times
the recommended level. Now... does that mean:
	1. my test kit is off - possible, but I seem to remember that 
		you (George) didn't get a reading on your kit either.
	2. the ferro vit dose of 2.5ml/10l doesn't generate a 0.1ppm 
		concentration. Impossible to tell without knowing the
		concentration of the ferro vit. If I remember correctly
		you had detailed concentrations of the Dupla drops. Because
		of the cost, I hate to waste too much of it, but that 
		is probably the next step. 
	3. there is something in my tap water that is reacting with the
		iron causing the low reading. I will pick up a bottle of
		distilled water to check this.
	4. I am reading the test kit wrong... Good thing I dropped chemistry
		for comp sci! never can tell on these things, but I suspect
		that even if I am reading it wrong, I am not that far off.

My next step is to validate the samples using distilled water as a control
instead of tap water. I will also check Dupla drops (if someone has the
information on exact dosage to get 0.1ppm in distilled water). Has anyone
else used the Red Sea iron test kit ? As I said before, I am getting a 
0.1ppm reading on my 30gal plant tank that I only recently setup, but then
I don't do water changes on that tank.

If anyone has any other ideas to try I am open. 

Ted Fidder
   (fidder at drmail_dr.att.com) (303)-538-5106
   AT&T Bell Labs
   11900 Pecos Street 
   Denver, Colorado   80234