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At 03:48 AM 9/24/1999 -0400, Beverly Wladyka wrote:
>- - phosphate unknown (AqPharm test kits only available here and have
>proven _very_ unreliable.  Hach test kit is an unbelievable $420 Can.)

The Seachem kit is quite good, the US mail order places carry it.

>- - iron unkown (Sera tests available only here and are difficult to
>read.  Hach test kit is $150 Can.)

I sell Sera for $8 with a CO2 system or Tropica MasterGrow order.  With my
modified instructions it is a great kit.

>This tank was initially setup in April 99.  Within a few weeks, the same
>fuzzy green algae we now have, along with tufts of black beard algae,
>began to grow on leaves, decorations and glass.  Fertilizer was Flourish
>and Flourish Iron, no PMDD.

Boy this feels like phosphate.  Esp. when it takes right off like that.
You need that Seachem kit, if you can't find one let me know.

> When the lights were turned
>back on, PMDD in small quantities (2-6 ml daily) was resumed and algae
>reaffirmed itself wherever it had died back.  Water changes became more

I forgot about your PMDD.  You gotta get an iron test kit.   See above.

Oh, my modified Sera test kit instructions:

Use my copyrighted directions (C) Dave Gomberg, 1999:


The first trick in using this test is to figure out HOW to use it.
The instructions do not say exactly how to compare the tube with the
printed color chart.  Here is the method I have devised:

Use a plain white surface which is lit from the side, preferably by
diffuse daylight.  I happen to have a nice white Corning Pyroceram
counter saver in just the right place.  Read the tube by looking
down from above and observing the color of the fluid in the tube.
Read the chart by tilting it enough that it is free of shadows (if
set horizontally, shadows may be caused by wrinkles in the paper).

The Sera test kit has its first level of measurement at 250ppb
(parts per billion, ug per liter).  An easy way to extend the range
is to use five times the 5ml of water the instructions call for.  To
take 25ml of water, just extrapolate the existing scale on the
cylinder which goes to 20ml.  This will mean that the faintest
printed pink color corresponds to 50ppb of Fe++.  And when measuring
low concentrations, use only one drop of indicator.

You will notice that the faintest printed pink is actually rather
strongly colored.  It is possible to detect a bit of pink that is
quite a bit fainter than the faintest printed color.   Although it
is difficult to quantify such low levels, they can be used to
detect the presence of SOME iron.  One can wildly extrapolate
values to such faint colors, but they should not be relied on.

As delivered, the test appears not to measure chelated iron.
However, if the tube is left alone for a protracted period, the
color deepens.  It is my interpretation that this represents the
indicator dye in the test chelating the Fe++ in preference to the
chelating agent in the aquarium water.  If this interpretation is
correct, then by waiting for a protracted period (a few hours), the
total iron (chelated and unchelated) can be measured, using the
same techniques as are used in the basic test.

Dave Gomberg, San Francisco            mailto:gomberg at wcf_com
For low cost CO2 systems that work:  http://www.wcf.com/co2iron 
Tropica MasterGrow in the USA:      http://www.wcf.com/tropica