Question:  How did fish survive for millions of years before
they invented electrically pumped fountains?

-----Original Message-----
From:   Jitka Hanzalova [SMTP:snail@IOL.CZ]
Sent:   Monday, September 28, 1998 4:13 AM
To:     PICLIST@MITVMA.MIT.EDU
Subject:        Re: [OT] Dissolved Oxygen Sensor

>> If you know the oxygen is low it's easy to add more with a fountain or
>> aerators but it's the not knowing that drive you nuts.
>
>  Too expensive I suppose to just run the fountain periodically?

>From what I know things are not that simple. If you run the aerators (in
winter) too often, the pond may cool to the point, when the fish dies from
the cold, eventually the pond may freeze up all the way to the bottom. So
the measurement of oxygen level is necessary to run aerators only as often
as needed.