On (13 Aug 97) Chris Phillips Rambled On  To Gary Ailes...
 CP> GA>tanks as well as a mechanical filter on the side.  The wide sweep
 CP> of GA>bubbles and water that break the water tension of a properly
 CP> installed GA>undergravel filter are superior to the "aquaclear" type
 CP> filteration for GA>air exchange.
 CP> Bubbling air through water more does not neccessarily mean more
 CP> aeration. Most gas exchange takes place at the surface. Even
 CP> non-moving water gets aerated.
 CP> Once again, the fish population dictates how vigorously you should
 CP> aerate.
  Missed the point, the bubling up moves the water, it allows for more
  surface exchange, as the other said, it breaks the surface tension.
  Needs not be a UG filter bubbling, any bubbling device will increase
  the surface exchange, it also will create currents so that the water
  is mixed and moving, no stagnate areas.
  Non moving water exchanges the least, also bubbling can cause gasses
  in water to be released faster.
 CP> GA>undergravel wouldn't work of course and I can tell you, the water
 CP> GA>quality went WAY DOWN!
 CP> I am not disagreeing with you, I am merely
 CP> trying to point out that a two filter setup is not REQUIRED for a
 CP> successful tank. I have seen people scared away from this hobby by
 CP> advice (especially from salespeople) that one MUST have at least two
 CP> filters. To the beginning aquarist, this means more expense as well as
 CP> another electrical outlet required.
   True,  with the wider array of filtering, one can get by with one
   way, I long ago ran a 60 gal FW tank with just a UG filter,
   had some pretty large Angels, 9 inch tinfoils (grew from 1 inch)
   they were quite well in such a setup,  Two filters  mean you have
   simply a backup in place, a outside filter can also reduce the need
   to vaccum the UG  filters bed.
   As to why the other persons water quality went down, if a UG filters
   off too long, the bacteria bed can change, less gas exchange at
   surface due to no motion means also  bad gasses  are slower to leave
   tank, build up.
   A non-powered mechanical filter makes a good backup to a UG.
 
 
... God created anchovies.  Satan put them on pizza.
___ Messenger V1.2 [Unreg]
--- PPoint 2.00
---------------