"dc" wrote in message
...
"Koi-Lo" Reply to NG Only wrote in
:

I would think the bacteria would start to die that many hours without
a fresh flow of oxygen rich water. I personally wouldn't do that.

The bacteria certainly wouldn't die. Nitrosomonas and nitrobacter bacteria
are a lot more resilient than people give credit.

This may be true but many filters, like the ACs have a deep 2 sponge well
that would quickly go anaerobic under the sponges after several hours.
Perhaps the shape and depth of the filtering material would make the
difference. I know when we lose power at night and I get them started again
come morning, I can sometimes smell a funky odor they don't emit when not
stopped for who knows how many hours. For some reason ACs don't always start
by themselves when the power comes back on.

What would happen is that the lack of circulation would prevent the
bacteria from doing its job properly. The low levels of dissolved O2
combined with the high concentration of ammonia present by morning would
mean it would take time for it to be processed out of the system once the
filter is switched back on.

That doesn't sound too good..... :-(

The pH would being to climb the moment circulation resumes as all the
built-up CO2 is forced out of the system, making the lingering ammonia all
the more dangerous.

It's just not a good idea to shut them off.
--
Koi-Lo....
Frugal ponding since 1995.
Aquariums since 1952.
My Pond & Aquarium Pages:
http://tinyurl.com/9do58
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