>From: Erik Olson <olson at phys_washington.edu>
>Date: Fri, 2 Jun 1995 07:05:36 -0700 (PDT)
>Subject: RUGF + UGF ???

>>       * 10 Gal. Tank
>>       * UGF/RUGF (1 plate has the standard uplift with a carbon filter, the
>> other plate
>>                   has a Penguin 550 Powerhead with the reverse
undergravel kit)
>>       * 1 Liter DIY suger/yeast CO2 generator hooked into the venturi intake
>> of the 
>>                  powerhead.
>Isn't having UGF on one plate and RUGF on the other going to be a bad thing?
>I mean, water will take the shortest path between them, and that might mean
>under the plate!  You might never get much flow through the gravel.  Granted
>this shouldn't be quite as bad as the guy at work who had a powerhead on
>one uplift tube and left the other tube open on the SAME plate (he 
>wondered why fish were dissapearing...).
Time will tell.  Seems to be working ok. The UGF is divided into two plates,
with edges all around the plates.  Plus most of the water is probably
defusing up or down before it reaches the edge of the plates. 

>Another observation:  Anyone ever done CO2 on a RUGF?  This seems like it 
>could be a potentially useful trick... The CO2 bubbles trapped below the 
>filter and must diffuse through the gravel bed, just like a reactor.

That is the effect I was hopping for.  I can see little bubbles come through
the gravel near the lift tube on a fairly regular basis. 

>>         pH is about (guessing because the test kit uses Bromothyl blue)
>>         7.6-8.0 and VERY resistant to lowering (2 7.0 Ph Right tablets had
>> NO effect)
>>         Hard water (No test kit yet).  
>This is always going to be true;  the amount of phosphate tablets required
>to drop the pH is enough to produce several healthy algae plagues.  Best
>to either accept the hard water or get the CO2 up & running.

The CO2 seems to have brought the pH down to between 7.2 to 7.6.  I have the
intake from the bottle going through a valve so I can control (to some
extent) the amound of gas going into the powerhead. I may tinker to see if I
can get to about 7.0 or 7.2. 

Patrick McClintick                   |   
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