Comments Below:

"Bill Deutschman" wrote in message
...

Peggy:

I'll rise to the challange. You argue that a holding tank needs lots
of ventillation to prevent odors. Most tanks don't have a large vent
hose so little exchange of air occurs and they are non-arobic.

Do you know of any system that uses a small air pump to bubble air
through the sewage to oxygenate it. Seems to me a small aquarium pump
would work but they all run on 115 volts and are noisy. This addition
would also require another hole in the tank but that is not hard to do
and would be worth the effort if the odors were eliminated.

bill
olcbill at charter dot net

Bill Deutschman, PhD Providing Laser Safety Training,
Oregon Laser Consultants Safety Audits, Computer Safety
455 Hillside Avenue Programs and CDRH Certification
Klamath Falls OR 97601-2337 for Laser Users.
541.882.3295

Hi Bill, I'll save Peggie the trouble and post her previous answer to the
same question:

Roger Long wrote:
Peggie,

I see some rather pricey system for pumping air into holding tanks to
aerate them. I'd like to try rigging up my own. How much air does it
take? Is there a critical amount below which nothing useful happens
or does any air help?

The Groco Sweetank pump moves 1.7 liters of air/minute, which is about
the minimum that'll work. Two things are important: a sufficient amount
of air to aerate the contents, and piping to distribute it throughout
the tank. Otherwise it'll only push foul gasses out the vent all the
time instead of only when the head is flushed.

You can see the compete manual for the Sweetank he
http://www.groco.net/parts/data/622.pdf


I'd like to avoid the 12 volt drain. Since we are in an area where
there will usually be wake motion, I have an idea for boat motion
powered pump.

I don't think it would produce enough air. The Sweetank requires only 3
watts of 12v power...not much of a battery drain. If even that's too
much for your current 12 resources, a relative small solar panel would
replace the drain on your battery.

It's price of $150-200 seems expensive...but the purchase price is
offset by what you're spending for tank products now, 'cuz a properly
aerated tank requires nothing else. So depending on how much you're
spending for tank products, the Sweetank can pay for itself in just a
few years.


--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"

--
Ken Heaton & Anne Tobin
Cape Breton Island, Canada
kenheaton AT ess wye dee DOT eastlink DOT ca