"Daniel Morrow" wrote in message
...

"Aqua Essentials" wrote in
message ...

Wrote:
I have CO2 setup and I want to run a small air pump on a timer
opposite
of my lighting schedule to help with aeration. Are there any
particular
airstones or diffusers that are better than the rest? Should I put
the
airstone or diffuser on the bottom of the tank or is it OK attached
via
suction cup a few inches from the surface? Thanks for any input,

Scott

Most airstones do a fairly similar job so I wouldn't worry whether one
does a better job or not. All airstones do is disturb the surface of
your aquarium and therefore increase oxygen absorption.


I think they might do a little more than that - the bubbles they emit
have a
higher air to water surface area than if they (the airstone) were never
used. Netmax? If the op has his/her own heavy duty air pump I would
recommend a ceramic airstone, otherwise I would recommend the rena
ceramic
airstones the most to the op. Good luck and later!

My understanding is that the longer the airstone bubble's contact time
is, the more effective it will be in bringing the dissolved gases ratio
to equilibrium with the atmosphere. Putting the airstone lower in the
tank helps with this and has the added benefit of providing some
turbulence in the tank (making the O2 and temperature distribution more
uniform). Your application will determine if these characteristics are
really of use to you, or you just want to increase surface turbulence
(break up the protein layer and dissipate a bit more CO2). Your most
effective dissipation of CO2 would come from the airstone being lower
(drawing the higher CO2/lower O2 water from the bottom, up to the
surface), but again, depends on your application (small or high
fish-load, % of plants, ppm difference in CO2 levels at the extremes, etc
etc ad nauseum ;~).

While there are differences in the quality of an airstone's output
(uniformity, longevity, size of bubbles, head pressure needed etc), I
haven't tested enough different types (long term) to make any comparisons
or useful recommendations, other than to consider adding a prefilter
(small in-line container with cotton) to prevent dust from accumulating
inside the airstone (which is a typical cause of their eventual
clogging). hth
--
www.NetMax.tk


It's common to put airsones at the bottom of your tank or even below
the gravel as they aren't always the prettiest of things!!


--
Aqua Essentials