Re: [APD] New notes on CO2 misting methods

["S. Hieber" <shieber at yahoo_com>]

The issue with a venturi is the water flow restriction. A 
low flow or modest 1-3 psi might not do the trick. I have
lots of pumps at which the the Kent Venturi laughs out
loud.

Constricting the output on a centrifugal pump won't harm it
at all, the rotor will just spin freely and happily in the
water in the volute and not accomplish any work. Exception
is, possbily, if there is no water flow at all and the pump
is not submerged, it then the pump might not get adequate
cooling since some non-submerged pumps rely on the water
flowing through the pump for cooling.

Hope that helps,
sh--- Daphne Freeman <daphne_freeman at charter.net> wrote:

> 
> OK, I am chiming in on this really late but I am trying
> to catch up.  As  I
> understand it, Tom was suggesting putting a venturi, fed
> with CO2, in the
> outflow line of a canister filter so the bubbles exit the
> spray bar yet
> everything is outside the tank.  Is the spray bar
> horizontal on the bottom
> shooting out into the tank?  I thought it was vertical
> shooting across the
> back wall.  Am I mixing methods?   
> 
> Scott posted that an in-line venturi could present an
> issue with Eheims due
> to back-pressure.  As luck would have it, I use a Pro
> Series Eheim.  The
> venturi seems like a much better idea than several
> diffusers from a
> maintenance standpoint (I have a 92 gallon corner so one
> diffuser wouldn't
> do it, maybe one venturi wouldn't, I am not sure)  Would
> getting a different
> brand canister filter with nothing in it yet a high
> output make sense in
> this scenario?  You could have the "real" filter spray
> bar blowing away from
> one side of the filter input and the "venturi" filter
> spraying away on the
> opposite side of the "real" filter input.  Everything
> would shoot away from
> the filter input.  I have a corner tank so I realize the
> configuration would
> be somewhat different and I have circulation issues
> anyway because of my
> tank dimensions.
> 
> According to the site with the Kent venturi, a medium to
> large power head
> can drive one of these venturis.  If it would hurt an
> Eheim, wouldn't it
> burn a medium power head up?
> 
> FWIW, previously, I attempted to replace my CO2 reactor
> in-tank power head
> with an external pump.  Due to noise and people
> subsequently refusing to
> speak to me, I had to go back to an internal (and large)
> power head to drive
> my Aquamedic reactor.  I love the idea of less "stuff" in
> my tank.
> 
> Am I missing the point on this and if not, any
> suggestions for a canister
> that is powerful enough the venturi wouldn't hurt it?  I
> cannot use a HOB
> filter, my stand/hood is one giant piece of furniture and
> I only have a few
> inches clearance between the back of the tank and the
> stand.  It has to
> mount in the hood (my reactor is here) or under the
> stand.
> 
> This sounds like an awesome idea, just not totally clear
> on it.
> 
> Thanks. 
> 
> Daphne
> 
> 
> 
> Then Scott H posted:
> 
> The Kent venturis are designed for a very high flow rate
> and reasonably good
> water pressure -- the kind of thing you can get with some
> of the larger sump
> pumps but I wouldn't expect it to work well with, e.g.,
> Ehiems, where the
> constriction of the venturi will present substanial
> "head" to the pump. 
> 
> 
> Tom posted:
> I've tried a new method for CO2 in the mist. No
> diffuser/Reactor at all.
> Fits on to the outflow of the canister filter outside the
> tank, cheaper than
> diffusers, maybe the same cost as very cheap diffuser/DIY
> reactor. Use a
> spray bar along the back lower side the entire length of
> the tank(or close).
> Add a Kent Marine venturi(or other brand etc) to the
> outflow from the
> canister. Add CO2 to this line in put.
> <http://www.aquariumpros.com/p-KEN12VENT,SKac.html> This
> produces a very
> fine mist along the entire back wall and can be directed
> through the plants
> very evenly for any sized tank. Other types of venturis
> are available(some
> cost a fair amount for better results such as the
> Mazzei).
> <http://www.ultralifedirect.com/protein_skimmers.htm> It
> is key to use very
> good venturis or the larger bubble size will influence
> the results. But the
> trade off is more pump pressure and flow drop(always some
> trade off). These
> venturis can be mounted outside AFTER the canister
> filter(which solves
> several issues for many). It does reduce flow rates, but
> nothing is inside
> the tank. 
> 
> 
> > _______________________________________________
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> Aquatic-Plants at actwin_com
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> 

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