Mortar is generally for use as the bonding course for brick and block. It
has extra lime added to make it a little bit more sticky. In fact the old
brick layers, before bag mortar, use to slake quick lime overnight before
mixing in the Portland cement. Concrete on the other hand does not have the
added lime, but does generate some lime, as calcium hydroxide during the
hydration process. Mix the concrete with the least amount of water that you
can work with to make the concrete more dense, and it will be slower
releasing the lime water. Let it cure with moisture, preferably 28 days, as
this reduces the internal pore size and makes the concrete more watertight.
Allow the concrete to dry for several days to get air into the pores and it
will become much harder for the lime water to pass through the air breaks.
You can also use an acrylic additive that improves the watertightness. Then
just monitor pH, and if needed do partial water changes until it stabilizes.
--
RichToyBox
http://www.geocities.com/richtoybox/pondintro.html


"Michael Shaffer" wrote in message
...
No, mortar.. like concrete but less strong and doesn't have lime (bad
for fish.)

jon wrote:
Do you mean concrete ?
"Michael Shaffer" wrote in message
...

I have about a 20'x 4' stream to do.. how much would mortar cost for
that?