[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Eheim CO2 Diffuser/Optimum

A follow-up to Dave Gomberg's comment on the Eheim ceramic CO2 diffuser.
I paid $22 bucks for mine mail order (That Pet Place or Pet Warehouse).
I didn't think for one minute that the little one inch thingy could
supply enough CO2 for a fast growing brightly lit 125 gal. tank with an
overflow and sump-but decided to experiment anyway.  I had trouble
finding an adapter for stepping down the tubing size to the small tubing
Eheim uses, but found that a regular plastic air line adapter from my
LFS fit both sizes of tubing well for a tight fit.  (I don't have any
worry that the slight pressure required for driving the CO2 through the
ceramic disk will cause the tubing to pop off the adapter or hose

I've been up and running for one month now and have been amazed at how
well the unit works.  The slight pressure allows for very accurate
regulation of CO2 input.  With a fixed KH (alkalinity) in the range of
4-6 dKH I can regulate the pH to +/- 0.05 pH (Pinpoint Marine pH
monitor) quite easily.  The current setup is an old SandPoint II
regulator and metering valve.  The CO2/pH regulation is so accurate that
I can open up the metering valve a bit during water changes to keep the
pH right where I want it while the baking soda and tap water dissolve,
outgas and settle in.  After a few hours I step the valve back and the
pH is maintained reliably until the next water change. 

If the unit continues to work this well for another month or so, I'll be
giving the toss to my regular Dupla and other brand CO2 diffusers for
this elegant and simple solution.  The tiny unit attached to the back of
a black-backed aquarium is completely unobtrusive as well.  I probably
won't even move it to the sump.

While I'm at it, I'll bite at the 'optimum' question:

1.	Aesthetically pleasing ++++  (over the last three years my
definition of 'aesthetically pleasing' has changed from 'power growing'
with giant sword plants, anubias and 18" bolbitis fronds to an
aquascaped approach using Malaysian driftwood and petrified wood with
mostly stem and ground cover plants; my tweezers/scissors time has

2.	Avoid algae outbreaks and other calamities +++ (I thought of
quitting this hobby a couple of years ago when my large tank melted down
into a stinking algae bloom for the second time in a year; I get quite
edgy when things start getting out of control; about all I can handle is
a little spot algae on the glass and the rare tuft or two of this or

3.	Simple, elegant gadgetry ++ (I like good 'stuff' including Nupro
valves, Victor regulators, new CO2 bottles and Eheim filters, but I want
the gadgetry reduced to the absolute simplest minimum; I don't want a
pile of ballasts and wiring and tubing all over the place; I have
somewhat the opposite reaction to George B's comment about opening the
cabinet doors; I am slightly embarrassed when I open up my cabinet doors
because I think if I was really clever, I would have found a way to
simplify the setup quite a bit; I don't want a perfectly purring nuclear
power plant under my tank; I just want to grow plants)

4.	I want to know how everything works ++ (thanks to many of you
I've learned a lot about what's going on in our planted aquaria)

5.	Low maintenance ++ (I don't need minimum or super low
maintenance; but I don't a lot of time battling problems either; an hour
or two per week is about right)

Regards, Steve Dixon in warm and sunny San Francisco