I started digging a small pond last month and what started out as
digging an unused fire pit a bit deeper has blossomed into a somewhat
larger project. It has grown from my original idea of basically
digging a hole and putting a liner in it to a skimmer, pump and
visions of a short stream running down the side. Anyway, there are
some cinderblocks that used to be around the fire pit (there are more
that used to hold firewood and the like) that have been outside in the
elements for at least three years with no fire, and probably longer
than that. I think they'd have most of the nasties leached out of
them long ago, but more than one person has said not to use them in a
pond. While I don't plan on having fish, I'd rather not make it
impossible in the future. I'm not going to use any mortar or
anything, just use them around the edge for a border and to hold the
liner. Is this a no-no?

What it looked like last month
http://i181.photobucket.com/albums/x...c162007009.jpg


What it looks like now
http://i181.photobucket.com/albums/x...n302008001.jpg

On Wed, 30 Jan 2008 21:26:23 CST, Galen Hekhuis
wrote:

While I don't plan on having fish, I'd rather not make it
impossible in the future. I'm not going to use any mortar or
anything, just use them around the edge for a border and to hold the
liner. Is this a no-no?

Feel free to whatever you want. Most people who use blocks use them
under the liner so they aren't in contact with the water, but I use
several to support pots and anchor iris in the pond and don't have pH
problems because of the blocks. I prefer a more decorative stone
around the pond as a collar, but if they aren't in the water it isn't
going to matter what you use.

The picture looks like you are beginning to enjoy the project. I
have friends with a skimmer filter on their pond and it works well for
them. I put up a couple pictures of their pond from the 2002 pond
tour. (No he didn't do the work himself.) I don't have a picture
showing the skimmer filter, but it looks about the size of your bucket
and notice they use stone on the bottom of their pond. The second
picture is of their fish at the time. They had a pH crash last year
(Heavy rains and lack of monitoring.) and lost many of the fish, but
it worked well for several years for fish and toads.
--
Hal Middle Georgia, Zone 8
http://tinyurl.com/2fxzcb

"Galen Hekhuis" wrote in message
...
I started digging a small pond last month and what started out as
digging an unused fire pit a bit deeper has blossomed into a somewhat
larger project. It has grown from my original idea of basically
digging a hole and putting a liner in it to a skimmer, pump and
visions of a short stream running down the side. Anyway, there are
some cinderblocks that used to be around the fire pit (there are more
that used to hold firewood and the like) that have been outside in the
elements for at least three years with no fire, and probably longer
than that. I think they'd have most of the nasties leached out of
them long ago, but more than one person has said not to use them in a
pond. While I don't plan on having fish, I'd rather not make it
impossible in the future. I'm not going to use any mortar or
anything, just use them around the edge for a border and to hold the
liner. Is this a no-no?

What it looked like last month
http://i181.photobucket.com/albums/x...c162007009.jpg


What it looks like now
http://i181.photobucket.com/albums/x...n302008001.jpg

.

Concrete block is made from Portland Cement, lightweight aggregate, and
water. The Portland cement reacts with the water to produce what is called
calcium silicate hydrate gel, which is the glue that gives the concrete its
strength. Byproducts of the reaction are calcium hydroxide and heat.
Calcium hydroxide is hydrated lime, which has a pH of almost 13.

The quantity of calcium hydroxide is not very high, and aging, or soaking
will remove much of it. A small pond, without much water and a bunch of new
block could create a situation in which the pH would be extremely high for
fish or plants. With old block, there may not be enough of the calcium
hydroxide left to influence the pH at all. If the pH goes up, and there are
no fish, I would add muratic acid to lower the pH. If there are fish, I
would use baking soda, which will bring the pH down to about 8.4 or close.
I think my koi ponds with high KH from baking soda is no longer a great
place for plants, since many of the minerals are not available to the plants
at pH much over 7.

--
RichToyBox
http://www.geocities.com/richtoybox/pondintro.html
Zone 7A/B Virginia

"RichToyBox" wrote in message
...

If there are fish, I
would use baking soda, which will bring the pH down to about 8.4 or close.
==================================
Baking Soda lowers PH?
--

RM....
Frugal ponding since 1995.
rec.ponder since late 1996.
Zone 6. Middle TN USA
~~~~ }((((* ~~~ }{{{{(ö

On Thu, 31 Jan 2008 17:55:22 CST, "Reel McKoi"
wrote:

If there are fish, I
would use baking soda, which will bring the pH down to about 8.4 or close.
==================================
Baking Soda lowers PH?

Been napping again? Yes, it can bring it down below 9 in some cases
and is a better choice than acid!
--
Hal Middle Georgia, Zone 8
http://tinyurl.com/2fxzcb

"Hal" wrote in message
...
On Thu, 31 Jan 2008 17:55:22 CST, "Reel McKoi"
wrote:

If there are fish, I
would use baking soda, which will bring the pH down to about 8.4 or
close.
==================================
Baking Soda lowers PH?

Been napping again?

Yes! :-)) Every night after supper.

Yes, it can bring it down below 9 in some cases
and is a better choice than acid!

That's good to know. Thanks.
--
RM....
Frugal ponding since 1995.
rec.ponder since late 1996.
Zone 6. Middle TN USA
~~~~ }((((* ~~~ }{{{{(ö

Galen,

Looks like hard work...worth it, tho'.

Hal and RTB have covered the bases pretty well in my ignorant
opinion.Our pond is cement. Once it has aged, it is no real problem.
Our plants thrive and the fish as well.

Please keep us posted as you proceed.

Jim

On Thu, 31 Jan 2008 09:06:40 CST, "RichToyBox"
wrote:

I think my koi ponds with high KH from baking soda is no longer a great
place for plants, since many of the minerals are not available to the plants
at pH much over 7.

There is a little more leeway then 7. See this chart:
http://preview.tinyurl.com/yweqz7 ~ jan :-)
------------
Zone 7a, SE Washington State
Ponds: www.jjspond.us

On Fri, 1 Feb 2008 21:21:46 CST, ~ jan wrote:

There is a little more leeway then 7. See this chart:
http://preview.tinyurl.com/yweqz7 ~ jan :-)

Cool chart! Thanks.
--
Hal Middle Georgia, Zone 8
http://tinyurl.com/2fxzcb

"~ jan" wrote in message
...
On Thu, 31 Jan 2008 09:06:40 CST, "RichToyBox"
wrote:

I think my koi ponds with high KH from baking soda is no longer a great
place for plants, since many of the minerals are not available to the
plants
at pH much over 7.

There is a little more leeway then 7. See this chart:
http://preview.tinyurl.com/yweqz7 ~ jan :-)
------------
Zone 7a, SE Washington State
Ponds: www.jjspond.us

Jan you are right about the ranges, but iron and other metals seem to have
much lower availabilities at the 8.4 pH of a well buffered pond. In the
good old days of ignorance, when we first started ponding, I could grow
hyacinths by the barrel and they were almost 2 feet tall, lettuce that was
over 1 foot across and couldn't carry it to the compost pile fast enough,
parrots feather thick enough that my dog, pekingese, would walk out part way
across the pond, pickerel would go nuts. Now, with much better water
quality for the koi, I have trouble getting any of these to survive, much
less thrive.

I know that nitrates are there, too many, and phosphates are high, and I add
potash, yet the lush plants that I used to have are no longer. I have tried
them in what used to be gravel bog filter boxes, where there are no fish, so
it isn't the case of them being considered a salad bar.

--
RichToyBox
http://www.geocities.com/richtoybox/pondintro.html
Zone 7A/B Virginia

On Sun, 3 Feb 2008 09:15:30 CST, "RichToyBox"
wrote:

Jan you are right about the ranges, but iron and other metals seem to have
much lower availabilities at the 8.4 pH of a well buffered pond. In the
good old days of ignorance, when we first started ponding, I could grow
hyacinths by the barrel and they were almost 2 feet tall, lettuce that was
over 1 foot across and couldn't carry it to the compost pile fast enough,
parrots feather thick enough that my dog, pekingese, would walk out part way
across the pond, pickerel would go nuts. Now, with much better water
quality for the koi, I have trouble getting any of these to survive, much
less thrive.

Yes, everything becomes more difficult at 8.4. Still.... at 7.8-8.0 I can't
grow water hyacinth like I use to anymore either. I use to have similar
success as you, but now they just fade away in the pre-filter. ~ jan
------------
Zone 7a, SE Washington State
Ponds: www.jjspond.us

You guys have got me wondering about our system. The hyacinth and
celery still grow wildly in the veggie filters. Maybe our water is
bad. I will have to take a look at the quality anew once things start
growing.

Jim

try water celery.

BTW, the water celery in my "inside the pond under the plastic" is doing fine. the
watercress I put in died. Ingrid

On Mon, 4 Feb 2008 20:53:30 CST, wrote:

try water celery.

Our blueberries want very acid soil. Interesting to see what
nutrients they can't get at that ph. Thanks.

jim