[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[APD] Re: etching

* From: Joey Choochootrain <hubbahubbahehe at yahoo_com>
what exactly causes etching on glass aquarium tanks??

I have tight-fitting glass plates over my tanks to keep CO2 from
escaping. When the lights are on during the day the top layer of water in
the tank warms up, and when the lights go off at night there is a lot of
condensation from the warmed water on the glass. The next day the lights go on and dry up this condensation. The SiO2 dissolves in the condensed water and when the water dries up the SIO2 is redeposited. After only a few months I get cloudy little rings where the drops form and then dry out. After a year or two the glass gets so cloudy that it cuts out a significant amount of light. I have tried various kinds of scouring, but I haven't found anything that scours this redeposited glass off without scratching the glass and making it just as cloudy. Fine cerium oxide powder is supposed to polish glass, but I have never been able to make any kind of impression on the clouded glass with mere elbow grease. Perhaps, if I had a very powerful high speed drill motor that could drive a felt scrubber with cerium oxide, I might be able to see some progress.

The thin layer of silicon works really well. It cuts out very little light, prevents etching, and the deposits that do form on it from tank water that splashes up and dries can be easily removed without damaging the silicon coating. Whereas I was looking at costs of over $50.00 every two years to replace my tank covers, with the silicon coating, it looks like the covers will last indefinitely.

-- Paul Krombholz in warming central Mississippi _______________________________________________ Aquatic-Plants mailing list Aquatic-Plants at actwin_com http://www.actwin.com/mailman/listinfo.cgi/aquatic-plants