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Re: CO2 controller....

George Booth wrote:

> I would like to challenge your statement concerning pH in natural ponds and
> the state of fish and plants in them.

> I assume by natural ponds you are referring to bodies of water with more
> than 100 gallons of water in them. What is your lower limit for a natural
> pond under consideration? 1,000 gallons? 10,000 gallons?  1,000,000 gallons?
> I hope we're not talking about the footprint ponds bettas supposedly live
> in.

> Could you quantify the "huge pH swings" you are referring to? Would this be
> a change from 8.0 to 7.6? 8.3 to 7.0? 8.3 to 4.5? I'm curious to know what
> could cause a "huge" pH swing in a large body of water. A spring rainstorm?
> A 1000-year storm yielding 3" of rain per hour? A semi-trailer tank truck
> loaded with CO2 crashing into the pond and exploding?

Plant and algae that use bicarbonate as a carbon source can force pH up
to ~10.  A fertile pond supporting a lot of plant and algae growth will
have pH swings from a morning low near 7 to a high of 10 over the course
of a few hours.

I saw this in a commercial fishery in New Mexico, and I believe it's a
common occurence in ponds and wetlands all over the place.

All water parameters in a stream - especially in a small stream - are
subject to large variations.  The variations occur over short periods of
time because of runoff events and over small distances near the
confluence of tributaries.

These changes are natural and common.   Whether or not fish find them
stressful is another question entirely.

Roger Miller.