I just installed mine but I think it is not working properly and I
wanted
another opinion. Obviously they are very simple and there is not
much to go
wrong, but I think my 4 dKH standard solution is bad. I have the Red
Sea
model, by the way, which comes with indicator, but no standard
solution.
They tell you to use tank water, which I don't want to do as the
tank is 6
dKH and has an unknown amount of phosphates etc in it.
I made the 4 dKH standard myself with baking soda, RO/DI water and a
series
of dilutions. A KH test kit verified that it is correct, but as I used
kitchen glassware maybe there was enough residue from detergent to
mess
things up. My RO/DO filter shows 0-1 ppm TDS as it should, so it is
still
working well... but maybe not well enough for this.
When I added the indicator to the solution, it immediately turned
green,
about the shade of green that you want to see when the CO2 in the
aquariumis
at the right level. For a sample of the reference that has not had
CO2 added
to it, the solution should be blue, right?
In the tank, the solution in the drop checker stubbornly stays
green, even
after the overnight lights-out.
I put a sample of the solution + indicator into a graduated cylinder
to see
if it was sensitive to pH changes at all. If I blow in to it with a
straw,
the CO2 in my breath turns in yellow, as expected. Shaking it to
drive off
CO2 got it down to blue. The strange thing is, it stayed blue
overnight. If
the solution was off I would have expected it to bounce back to
green when
left alone.
Some forum posts have said that drop checkers may not work right
until they
have broken in for a week or so, but that just doesn't sound right
to me.
Does anyone have ideas, and/or a convenient source of good 4 dKH
reference
solution? It's easy to make, but maybe not easy enough to make one
that's
pure enough in a kitchen.
Thanks,
MS
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