Path: utzoo!hoptoad!ptsfa!pyramid!pyrnj!rutgers!cbmvax!sterling
From: sterling@cbmvax.UUCP (Rick Sterling QA)
Newsgroups: alt.aquaria
Subject: Re: Tank Size
Message-ID: <3188@cbmvax.UUCP>
Date: 25 Jan 88 13:17:22 GMT
References: <5927@sol.ARPA> <2196@gryphon.CTS.COM> <2634@calmasd.GE.COM>
Reply-To: sterling@cbmvax.UUCP (Rick Sterling QA)
Organization: Commodore Technology, West Chester, PA
Lines: 41

In article <2634@calmasd.GE.COM> version B 2.10.3 4.3bsd-beta 6/6/85; site cbmvax.UUCP cbmvax!rutgers!ames!aurora!agate!ucbvax!sdcsvax!sdcc6!calmasd!jnp jnp@calmasd.GE.COM (John Pantone) writes:
> > The question was asked "are hex tanks any good".
> 
> Many folk have, correctly, pointed out the relationship between surface area
> and number of fish - but there is more to the story.
> 
> What we're really after here is oxygen/carbon dioxide exchange (O2 into the
> water - CO2 out) - this normally occurs at the surface of the water/tank.
                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> If nothing else is done a hex tank is really not "very big" and can't handle
> too many fish.  There is a solution, though, wich we used in our hex tank
> several years ago:
> 
> put a glass or plastic tube 1/2 to 1 inch in diameter into the tank - and
> support the bottom in such a way that water can enter the tube (we propped
> it on a piece of lava-rock).  Get one of those air-bubble stones and a
> plastic tube (can run down the large tube) and connect to an air pump.  This
> will do 2 things - 1 it will "lift" water up the tube, and cause increased
> gas exchange at the surface - 2 it will aerate the water "artificially" with
> all those bubbles - increasing the gas exchange again.
> 
> I tried to calculate the efficiency of this, and ran across some figures
> about moving water in streams, etc. which indicates that it could as much as
> double the effective surface area of a tank.
> 
> -- 
> These opinions are solely mine and in no way reflect those of my employer.  
> John M. Pantone @ GE/Calma R&D, 9805 Scranton Rd., San Diego, CA 92121
> ...{ucbvax|decvax}!sdcsvax!calmasd!jnp   jnp@calmasd.GE.COM   GEnie: J.PANTONE

 I've always been under the impression that O2<>CO2 transfer can only occur
at the surface where atmospheric and water pressure are at equillibrium and
that air lift systems will help increase water turn-over at the surface but
no appreciable gas exchange occurs in the bubbles. Any authorities out there?

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   Rick Sterling             COMMODORE AMIGA TEST ENGINEERING
                             UUCP  ...{allegra,ihnp4,rutgers}!cbmvax!sterling 
  // /_ |\/||/_ /_           PHONE 215-431-9275
\X/ /  \|  ||\//  \          ` CALM DOWN ! It's only 1's and 0's ! '
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