On 13 Sep 2006 13:04:52 -0700, wrote:

I would like to secure and seal the
rocks so that they are less likely to be moved or disturbed. Is there a
mix, like cement, that can be safely used to seal these rocks? This
pond has goldfish in it so I can't do anything that would harm them.

While it is true the lime in concretes is of a variety that can cause
pH rise to as high as 12 the high pH isn't forever. You can use
concrete if you will move the fish while construction is in progress
and allow the concrete to age, or use an acid (muriatic acid) to wash
it down a few times until the concrete stops raising the pH so high,
when it drops down to pH 9 or less it isn't likely to harm the
goldfish and mine even seem to like pH 7.8 to 8.2.

Regards,

Hal