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Re: Simple, Cheap, easy, CO2 systems

 > Date: Sat, 05 Oct 2002 11:51:04 -0500 From: "Joelle Wright"
 > <Joelle1 at Witty_org> Subject: Re: Simple, Cheap, easy, CO2 systems
 >> Well here's some photos of a simple multi tank CO2 system and
 >> detailed parts all available at Home Depot. Regulator is a Cornelius
 >> UL listed regulator, very commonly used, similar to what most beer
 >> places/ commercial ice sales/soda fountain vendor companies sell,
 >> install. Runs about 50$.
 > The problem I have with this DIY cheap approach is the use of these
 > brewery regulators. They are not factory preset to control the delivery
 > of Co2 for an aquarium application.  Why should they be?

They should *not* be, for they are deliberately designed to be adjustable.
That is their main function! They give an adjustable lower output pressure 
from a full or partially empty tank. [The "factory preset" ones allow 
exactly the same adjustments, but may cheat you out of a handle to make it 
easy to do and maybe even gages to see what you are doing.]

 > They are for brewing after all.  Don't think slapping a good needle
 > valve on the end will fix this fatal flaw.

What fatal flaw? That they let you adjust pressure for optimum use at 
various tank depths? That they let you set for minimum pressure to reduce 
any leakage losses? I fail to find any flaw, much less a fatal one, here.

 > Needle valves are for
 > fine-tuning the flow, not pressure regulation.

So? What does that have to do with anything? They keep a relatively 
constant flow from full tank to end of tank, with a few percent rise near 
the end when the regulator hasn't enough pressure across it to keep the 
output pressure exactly constant. They give constant flow because the 
regulator gives them a constant pressure. Wildly different from using an 
Eheim diffuser with a check valve that only drops a constant pressure and 
allows huge flow increase (aka "dumping") with just a few percent increase 
in incoming pressure.

 > Use these regulators at your own risk.  The entire dumping phenomenon
 > was caused by a guy selling that regulator for aquariums.  The
 > advantage those so-called expensive aquarium regulators have over the
 > cheap brewery regulators are they are factory preset for aquarium use.
 > That's it.  No need for all the techno-babble. They also have a company
 > backing them up with warrantees.

Dumping had absolutely nothing to do with regulator quality, and a lot to 
do with improper use of a check-valve/diffuser as a flow restrictor. Read 
the history before getting too indignant. Your comments are misplaced and 
do the hobby little good, IMHO.

 > How many of you that bought one of those bewery regulators for your
 > aquarium had the thing dump on you? How many dumping victims got any
 > compensation from that guy you bought them from?  The guy still won't
 > admit the thing is faulty. Now Tom Barr is advocating using similar
 > stuff....

Maybe because the regulators work just fine (if you don't try to use an
Eheim diffuser to control flow rate). I have bought several and never had 
a problem, but I first bothered to understand what I was doing.

Used with a good flow-restricting valve, they work very well, indeed. The 
expensive ones sold in the aquarium trade have exactly the same tendency 
to let pressure rise a little bit, near end of tank. That is a designed-in 
property of *all* single-stage regulators. If used with no needle valve 
and an Eheim check valve (as the only flow restrictor), they would dump 
every bit as much.

 >> If you have a positive suction style reactors......powerheads or
 >> filters sucking the CO2 gas out all the time and you make a drip in
 >> the CO2/air line no water will back into this set up even if the tank
 >> runs zero pressure for days.....
 >> So you don't need a check valve
 > When the powerhead or filter inevitably clogs or you have a power
 > outage what happens then?  You get a back flow straight into the needle
 > valve, regulator and tank.  I won't even go into the possible
 > consequences should that happen.

Hogwash! Exactly how many times has that happened to you? The physics of 
the situation you describe doesn't lend itself to that mode of failure, 
AFAIK. It is virtually impossible to get water back through the needle 
valve, much less into a regulator or tank. You would need to create a 
vacuum at the tank to do so.

Methinks thou dost worry about entirely the wrong things.

 > The advocacy here should be tempered with cautious <experiment at your
 > own risk> disclaimers so everyone knows these DIY approaches come with
 > many risks.

The most serious real risks are the normal ones of dealing with a 
container pressurized to 800 psi.

Those have more to do with connection skills, valve ratings, etc. No one 
should do DIY stuff if they don't understand that the tank falling and 
breaking that top valve can create a mini-rocket and/or freeze your toes 
with dry ice that suddenly forms. They should know that it is bad practice 
to use teflon tape ahead of a needle valve, too. [I see some of your 
precious LFS commercial systems doing exactly that, though!]


Wright Huntley -- 209 521-0557 -- 731 Loletta Ave, Modesto CA 95351

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