Scale and algae control systems in fountains

We have an outdoor fountain with four bronze Whitetail deer and
reeds. This is an iconic work of art in downtown Indianapolis and we
are under great pressure to have the fountain operate as much of the
year as possible.  Each year, we struggle with two issues.

1. The fountain deposits scale on the bronze.  It has been suggested
that we consider installing a Colloid-A-Tron (CAT) unit in the
plumbing system.  Here's a description of how it works from Fountain
Dynamics

    <URL:http://www.fluiddynamicsna.com/scalepreventionhowitworks.html>

As water passes through our product it is subjected to a turbulent
interaction with a catalytic core made of a special alloy. The
dissimilar metals and the water create a battery effect generating a
very small electrical current.

This electric current causes an important change to take place. A
percentage of the Calcium Carbonate in the water comes out of
solution and goes into suspension in the form of Aragonite crystals.
Although just microscopic in size these crystals grow attracting
more Calcium Carbonate decreasing scale accumulation in previously
untreated systems.

The Aragonite crystal formations remain suspended in the water and
pass harmlessly through the system. Changes in temperature or pH no
longer lead to hard scale deposits as the calcium carbonate that may
have been deposited as Calcite has previously been converted to
Aragonite and is effectively trapped in suspension.

As the process repeats itself, newly created Aragonite crystal
formations are continually produced thus preventing scale deposits.
The process also continues to gradually remove any scale that may
have accumulated in the past. This is due to the water being under
saturated with dissolved calcium.

2. A great deal of algae builds up in the pond.  We have been
advised against using chemicals to treat the algae as they are
harmful to the bronze.  Does anyone have experience using ultrasonic
algae control systems in fountains that include bronze sculpture?

For more information see

    <URL:http://pondalgaesolutions.com/ultrasonicalgaecontrol.html>

I appreciate hearing from anyone with first-hand knowledge of how
these two newer technologies work and their effect, if any, on
bronze works of art.

Amy McKune
Director of Museum Collections
Eiteljorg Museum of American Indians and Western Art
500 W Washington St
Indianapolis IN  46204
317-275-1358
Fax: 317-275-1400


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                  Conservation DistList Instance 25:48
                  Distributed: Friday, April 27, 2012
                       Message Id: cdl-25-48-013
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