I have had a pond lined with river cobble on the sides and pebbles on
the bottom running for 4 years now. It looks very natural and is well
planted with lilies and various marginal plants. THe fish do well the
water has never been green and I have checked the bottom next to the
liner and there is zero accumulated deposits. I do have a strong
water flow giving good cirulation. I am happy with it. I like the
natural appearance. One point though - we paid more for very
attractively coloured river rock. A waste of money - after some months
the rocks grow a nice covering of beneficial algae so dont spend money
on fancy rocks.

Others like their rockless ponds just as much I am sure.

Greg.
JGW wrote:
We're getting ready to build our new pond. The contractor wants to
line the walls and bottom with rocks, which he says will serve as a
great huge biofilter. I have read that it's impossible to keep the
pond clean with rocks on the bottom, and that they can trap hydrogen
sulfide gas.

What are your thoughts?

Thanks.

Joan
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