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RE: Estimative method/Barr method

> -----Original Message-----
> From: Thomas Barr [mailto:tcbiii at earthlink_net]
> Sent: Thursday, April 03, 2003 10:11 AM
> To: Charles Kuehnl
> Subject: Re: Estimative method/Barr method
> > With high GH and KH and pH tap water, a 40-60% water change is
taking my
> > CO2 down to around 5 ppm (or whatever normal ppm is without
> > It takes about 1-2 days (sometimes more) for the pH to recover to
> > 7.1-7.3 range I try to keep it in.
> A decent CO2 system would keep the pH in a good range within 1 hour or

Within the last month or so I have changed my filter and CO2 setup.  I
have been so busy since then that I have not really had a chance to
observe what is going on.  It seems that it was initially much better on
the response time but I honestly could not say for sure.  I just was not
paying attention.  Everything seemed to be working fine until the crater
over spring break.

> If it takes days to hit a good range, how is it that the system is
able to
> keep up with the plant's uptake depletion rates?

It may not be doing that right now.
> CO2 is the biggest issue for you. And it will cause the most grief if
> not well set up and responsive.

I have had more experience with this one and do not want any more.  I am
a true believer on this one.
> > From what you have said
> > about CO2 and algae, I could imagine this (low CO2) being a really
bad deal with a
> > lot of light.  
> It should not be an issue. Add more flow through the CO2 diffuser/add
> circulation ton the tank, get something that mixes the CO2
better/faster etc
> etc.

In the filter change I mentioned above I went to an internal filter
(Eheim Aquaball) with about 100-127 gph flow rate (I bought a couple of
pumps and have swapped them, do not recall right now which one is in
there).  This is in a 10 gallon tank but with all the openings in the
spray bar there is a pretty even and fairly gentle flow throughout (fish
do not have any trouble at all).  That is when the filter is clean,
anyway.  I added a spray bar at the same time (a sectional installation
set they advertise with this filter) that runs down the back side then
across the far end.  I have the spray bar set up so that there is flow
coming out of one joint at the far end of the tank and all along the far
side.  I do not think circulation is a problem unless I have too much
and it is channeling.  

The CO2 reactor is set up beside the filter with the flow outlet right
at the base of the filter.  Perhaps I should move the reactor to the
other end of the tank.  The tank is a little overgrown right now (little
time for maintenance) and that is probably affecting the circulation.
The reactor and pump would probably benefit from a cleaning though there
are no visible signs of a problem there.  I have not done it in a month
or better and there is a noticeable current at the flow outlet.  A
little filter maintenance is due though I have been doing that fairly

> > 2)  Your CO2 system returns to the desired value much quicker than
> Well not just mine, just about everyone's.
> > This would make me think there is something wrong with my CO2
> Me too.

From what you are saying I suspect I have a maintenance issue with the
reactor that is not visibly discernible.
> > the reactor needs cleaning more often than I am doing it; the water
> > is too high for good exchange; and/or the water flow is too low to
> > enough CO2 into the tank.
> Too low is far more likely. More will not hurt unless the unit is
> out gas bubbles etc.

The reactor instructions said more flow is better.  At the time I
recalled reading somewhere ( I thought here or a related website about
reactors) that it is better to have the water linger in contact with the
CO2 to improve the rate of solution in the water, hence a lower flow
rate is called for.  From my exposure to heat transfer I can also see
how a little more CO2 in a lot more water (high flow rate) would work
too.  It probably would be a lot faster as well.  Then again I'm an EE.
I take it you are of the high flow rate persuasion.  What do you think
is an appropriate range?

> > After you do a
> > 50% water change, how high does your pH go and how long does it take
> > your tank to come back to the desired pH?
> About 1 hour or so.
>  pH, KH, GH of the tap etc really doesn't matter.

This further reinforces my thoughts about this being a maintenance
issue.  I guess I have got some work to do - when I can find the time.

Thanks again Tom.
> Regards,
> Tom Barr

Charles Kuehnl