With a 25mm reducer and a piece of irregation pipe my venturi works wonderfull and cost only R30 in material. Any interst? If yes will post some pics and a materials list.

Hi,

A venturi is not good for your Koi!

Why would th venturi, getting lots of oxygen into the water not be good? You see them on all ponds. Can you maybe explain why they are not good?

Adi,

please read;

http://koionline.forumotion.com/equipment-f31/pond-aeration-t645.htm#3096

Would the size of the pond not also play a role?

No matter how big the pond is!

It is about this;
Chris Neaves................................

Quote:

We are always told a venturi dissolves OXYGEN into water. This is not entirely true. The atmosphere is around 80% nitrogen, 18 - 19% oxygen and 1 - 2% other minor gasses. A venturi pushes air into the water under pressure - not only oxygen.

Dry air contains roughly (by volume) 78.08% nitrogen, 20.95% oxygen, 0.93% argon, 0.038% carbon dioxide, and trace amounts of other gases. Air also contains a variable amount of water vapor, on average around 1%.

When using a venturi these gases are blown into the water by an extreme force.
This result in that the “dangerous gasses” stay in the water for quite a long time, is then taken up through the gills of the fish when the fish gather oxygen from the water.

This then leads to stress and other diseases.

When making us of a venturi, it is best to lift in out of the water, above the water line, this will help the gasses to escape before it enters the water.

_________________
Pieter J de Villiers
http://southafricankoi.11.forumer.com
"I am KoiMad...........but garlic wise!"
FEED GARLIC, NO PARASITES!!

ok, here is some picture as well as what I did. The nice part, you can regulate the air flow, and can switch it off completely too, and all this for not even R30....this is what u need.
2x 50mm tread to pipe fitting
2x 50mm reducer to 25mm
1x 25mm threaded connector
1x small piece irregation tube
1x irregation valve for the top

Here is what I did:
connect all pieces together, then drill a hole the size of your irregation tube just off centre in the 25mm threaded connector. Make a V cut at the bottom of the irregation tube, glue the tube in place, and the valve and it works!