"Tony Volk" wrote in message
...
Does anyone have any experience with how efficient these style diffusers
are? Anyone know of good data on how efficient the various diffusion
methods are? I don't need ultra-high levels of CO2, but I haven't seen
any
significant change in my pH or plant growth under my current (and
admittedly
half-assed) set-up. As I said before, I prefer the diffusion method, but
I'm open to building/buying a reactor if that's truly a much better way of
going about it. I certainly don't see my current bell set-up doing much
if
I add a second DIY bottle of CO2! Thanks,

Hi Tony,

I don't have any pesonal experience with this type of reactor, to be honest,
but I have my eye on one at the LFS which is very similar, and about the
same price.

What I have noticed about this type though is that two would be needed at
each end of a tank 50gal or larger.

I am currently using an active reactor, following the Tom Barr design, and
previously to that I was just feeding my dual bottle bubbles directly into a
venturi input of an internal filter.

It seems to me from using these two methods that one factor is actually
critical - and that is the the CO2 bubble has to spend as much time in
contact with the water as possible to diffuse - in the pre-Barr system this
used to happen by the output smashing into the substrate and then being
pushed around the tank to the input of the first filter, where the impeller
would break up any remaining bubbles and push them back towards to filter
with the CO2 on the venturi.

What I have noticed with the Barr Reactor is that while the bubbles are much
finer, the dissolved output water isn't getting as far around the tank as
previously. Short of modifying the main filter to put out a really strong
circular flow around the tank I can't seem to get this reactors output to go
as far.

I am still experimenting with different diffusion systems myself. My
instinct is to just whack the CO2 line onto the venturi of the power head to
get it around the tank, but I think the reactor actually does a great job of
making diffusable sized bubbles.

I guess what I'm getting at is that it's all a matter of experimentation and
customisation for the tank. If you do go with the product you provided the
link for, I'd say you'd need two with a bottle on each one - and get the
water moving as much as possible.

Oz

--
My Aquatic web Blog is at http://members.optusnet.com.au/ivan.smith

Tony