My 300 gallon preform has no waterfall or fountain. Can I just use a air
pump? Is there a small outdoor model? Or should I just get a indoor one
and keep it out of the weather? I have a bio/mech filter with a 1800 gph
pump that keeps everything clean. But the good bacteria it says need
oxygen as do the fish. So far the fish seem ok. Thank you

DD,
The 1800gph pump creating turbulence on the water surface will
probably be fine as long as you don't overload the pond with fish.
Oxygen transfer into the water primarily occurs at the surface. I
would probably hold off on getting an air pump and if I was very
worried about aeration would probably get another water pump to create
a water fountain or something that created more surface turbulence. I
just have a water pump outlet coming up through some bamboo to splash
the water and feel that it works fine, my goldfish are very active and
I have a lot of them in a pond around your size (I need to get the tape
measure out and figure out my volume).

James

"DD DDD" wrote in message
...
My 300 gallon preform has no waterfall or fountain. Can I just use a air
pump? Is there a small outdoor model? Or should I just get a indoor one
and keep it out of the weather? I have a bio/mech filter with a 1800 gph
pump that keeps everything clean. But the good bacteria it says need
oxygen as do the fish. So far the fish seem ok. Thank you
=======================
If the return from the filer is causing turbulence in the pond that should
be enough. Are your fish hanging at the surface gasping for oxygen?
--
McKoi.... the frugal ponder...
EVERYONE: "Please check people's headers for forgeries
before flushing." :-)
~~~ }((((o ~~~ }{{{{o ~~~ }(((((o

"DD DDD" wrote in message
...
My 300 gallon preform has no waterfall or fountain. Can I just use a air
pump? Is there a small outdoor model? Or should I just get a indoor one
and keep it out of the weather? I have a bio/mech filter with a 1800 gph
pump that keeps everything clean. But the good bacteria it says need
oxygen as do the fish. So far the fish seem ok. Thank you


As long as the water is circulating around the pond, and the fish load is
low, the pump should be sufficient. Try and maximize circulation by drawing
water into the pump as far as possible from the return from the filter. The
fish will notice the lack of oxygen before the bacteria do. Use your eyes
and nose to give you clues, if you notice the fish are gulping air bubbles
or hanging out near the surface or you smell a swampy smell it should be
clue that the oxygen levels are insufficient.

-S

(DD DDD) wrote:
My 300 gallon preform has no waterfall or fountain. Can I just use a air
pump? Is there a small outdoor model? Or should I just get a indoor one
and keep it out of the weather? I have a bio/mech filter with a 1800 gph
pump that keeps everything clean. But the good bacteria it says need
oxygen as do the fish. So far the fish seem ok. Thank you

Air pumps are basically for looks -- the bubbles help roil the water surface,
which helps with gas exchange, but the bubbles themselves don't add much oxygen.
Directing the discharge of your pump (1800gph in a 300g pond? Wow!) to roil the
surface will give you plenty of oxygen in the water.

Andy Hill wrote:

Air pumps are basically for looks

We have all seen fish die if an aquarium pond looses its aeration, so
they do work. They need to be sized to the pond. They have ratings on
the side of the box for different sized ponds. Warm water doesn't hold
much O2 and may need more aeration. The air pump for my pond cost
nearly $200.
--
Pardon my spam deterrent; send email to
18,000 gallon (17'x 47'x 2-4') lily pond garden in Zone 6
Cheers, Steve Henning in Reading, PA USA

my goldfish used to gasp for air in their 40g winter home until i added
an air pump. it's a rena brand and is only meant for internal use.

now that the pond is open, i have a waterfall to help with the gas
exchange. i put the rena pump in my pond as well - you cannot have too
much aereation. the rena pump is connected to a bubbler that comes on
from 9pm to 7am every day. i don't like they unnatural way that the
bubbles break the water, that's why i only run it at night. that and
the fact that the plants don't produce any oxygen at night are good
reasons to use and air pump.

my goldfish are all very happy and active and growing like weeds. i
like the way they come over to me and beg for food. ok, time for bed.
don't let the bed trolls bite!

Stephen Henning wrote:
Andy Hill wrote:

Air pumps are basically for looks

We have all seen fish die if an aquarium pond looses its aeration, so
they do work. They need to be sized to the pond. They have ratings on
the side of the box for different sized ponds. Warm water doesn't hold
much O2 and may need more aeration. The air pump for my pond cost
nearly $200.

I was unclear. Lots of folks believe that the bubbles themselves contribute to
the aeration. That's pretty much incorrect -- anything that roils the water
surface as well as a bubble column/wall will do just as good of a job
facilitating gas exchange as a bubble column/wall. In the OP's case, directing
the discharge of that monster pump along the surface will roil the surface
plenty.

"Andy Hill" wrote in message
...
Stephen Henning wrote:
Andy Hill wrote:

Air pumps are basically for looks

We have all seen fish die if an aquarium pond looses its aeration, so
they do work. They need to be sized to the pond. They have ratings on
the side of the box for different sized ponds. Warm water doesn't hold
much O2 and may need more aeration. The air pump for my pond cost
nearly $200.

I was unclear. Lots of folks believe that the bubbles themselves
contribute to
the aeration. That's pretty much incorrect -- anything that roils the
water
surface as well as a bubble column/wall will do just as good of a job
facilitating gas exchange as a bubble column/wall. In the OP's case,
directing
the discharge of that monster pump along the surface will roil the surface
plenty.
======================
I'm wondering if it would be too much current and roiling in a 300 gallon
pond. ????
--
McKoi.... the frugal ponder...
EVERYONE: "Please check people's headers for forgeries
before flushing." :-)
~~~ }((((o ~~~ }{{{{o ~~~ }(((((o

i don't think that is intirely true; i use co2 diffusion in my tanks to
increase the growth rate of plants. it's similar to an air bubbler. co2
is pushed into a tube which then forms bubbles. instead of rising
directly to the surface, they go along a plastic track which slows down
their ascent. as the bubbles rise, they diffuse into the water and
become smaller. co2 becomes measurable in the tank and it drops the ph
by 0.5 to 1 whole ph.

with air diffusion, i imagine that the bubbles do decrease in size to
some extent. since air is free and pletiful, their's no need to work
hard at diffusing it. just pump all you can in there and some will
diffuse. surface aggitation alone cannot get enough air in a tank if
there are many fish.

(DD DDD) wrote in
:

My 300 gallon preform has no waterfall or fountain. Can I just use a
air pump? Is there a small outdoor model? Or should I just get a
indoor one and keep it out of the weather? I have a bio/mech filter
with a 1800 gph pump that keeps everything clean. But the good
bacteria it says need oxygen as do the fish. So far the fish seem ok.
Thank you


Injecting air into the water is the best way to get o2 dissolved into
water. Just like co2 is added to soda pop and propane is added to
gasoline. Of course this would be a system for someone who has
everything. Maybe Richie Rich.

I have 5 ponds that I keep water flowing 3/4 of the year. Water flow is
just part of the aeration system. Like most things it takes different
parts in concert to make a whole system.

On the largest pond I have an air pump with air stones. The pump is in a
semi-water tight Tupperware container along with an outdoor thermometer.
I run the air pump all year long.

A water pump is not possible in the winter time.
I don't like or use a heater either.
This winter the ice was 6" thick. I don't have to make any holes in the
ice for the fish to breath. Air doesn't freeze so was constantly being
supplied to the fish under the ice. I couldn't see where the air was
exiting the pond but I don't care because I know the pump provides a
positive air flow.

I monitor the water temperature and on the coldest days (15deg) the
temperature was holding at 34.2. Much warmer than above the ice.

The pump a use is a $9 model from Wal-Mart. They last about 2 years come
rain, shine, or ice. I change the air stones twice a year. It works
great.

Hope this helps.

StOrEcRaFt wrote:

I couldn't see where the air was
exiting the pond but I don't care because I know the pump provides a
positive air flow.

Not necessarily. Pumps provide pressure. If the pressure rises too
high, it indicates the air flow has stopped. All good pumps come with a
chart showing air flow versus pressure. This way, if you have a pressure
gauge, you can tell your air flow by looking it up on the chart.
--
Pardon my spam deterrent; send email to
18,000 gallon (17'x 47'x 2-4') lily pond garden in Zone 6
Cheers, Steve Henning in Reading, PA USA