"Hal" wrote in message
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On Thu, 02 Jun 2005 14:05:35 GMT, " George"
wrote:

That is normal. And a 17.0 ppm drop in your alkalinity is nothing to be
worried about as long as it is in the normal range to begin with(~80
ppm).

You must be right, but baking soda gives higher readings much sooner.
I couldn't keep the numbers up with baking soda though. I even tried
double and triple dosing, but it was gone in a week. After the bout
with string algae I gave up on baking soda and plaster of Paris. I
just use limestone and ignore the numbers until they look better.

Regards,

Hal

Baking soda is a temperary solution, at best. Adding limestone rocks to
your water flow is the best solution, IMHO. By the way, alkalinity has
little affect on string algae, since it is present as a result of high
nutrient load in the water (aka, high nitrate concentrations).