October 22, 2004

Pond Q&A - Now Archived!

We're a little behind in the Q&A emails, so we're going to look
at three questions today...

But first, here's an important update:

For those of you who have missed previous Q&A articles, we've
decided to archive each days Pond Q&A on our weblog. Many of
your questions can be found and answered here, so before
sending us your questions, please review this page first:

Question #1>

Hi Brett,

I would like your advice, I brought a Fish Mate UV+BIO
Pressurised Pond Filter to control the algae, It appears to work
fine, the pond is 8ft * 6ft * 2feet deep with a waterfall. We
have 6 goldfish in the pond.

My question is in two parts.

1: We live in England in the North East of Yorkshire and over
winter the water will freeze, a friend has told me I can leave
the pump running as 'running water' won't freeze, is this true or
should I turn the pump off.

2: If I turn the pump off over winter, what happens to the
biologically active critters?

Any help will be gratefully received. I've enclosed a photo of
the pond and waterfall,



Malcolm Hills



HI Malcolm,

You can leave your pump running, and the water may not freeze,
but this is really not the best way to do this. As we've covered
in recent Pond Q&A's, it's much better to turn the pump off and
not circulate the water, as the water at the bottom of the pond
in winter will remain slightly warmer than at the surface. If
you circulate it, it is then colder all over and for your fish.
So, we recommend a de-icer..

If you're not able to find one near you, one of our readers send
in an inexpensive alternative, which we haven't tested - but
sounds interesting. She suggested floating a common 'beach ball'
in the pond, and as the wind moves it around - the ice will not
form in the pond. You could try that also...

To answer your second question, your good bacteria, or
'biologically active critters' as you called them, will die off
during winter anyway. Some will remain dormant, and start the
process all over again in Springtime, but leaving your pump
running will do little to keep them alive once the temperatures

Hope this helps,



Question #2>

Hi Brett

I really get lots of info. from your Q&A time.

I have a question for you, i know we are supposed to clean and
take pumps out in cold weather. I need to know how cold before we
take the pumps out. When the water is freezing or before it gets
that cold.

About what temp should this be done? I live in wyoming and it 's
getting pretty cold. And i have fish in the pond.

Thanks for all of the info.

jeannette in cold wyoming.



Hi Jeanette,

Well it sounds like it must be getting cold in many parts of the

Down here in Florida, it must have dropped down to under 70 today
;-) Hey, I have to at least take a friendly cheap shot at all
your Northerners every once in awhile (I used to be one, so it's
ok). I paid my dues, living up in 'the land of ice and snow.'
for ten years was enough.

Anyway, on to your questions...

The best time to remove your pumps is when the water is getting
cold enough that your fish aren't eating and their metabolism is
slowing down going into hibernation. It's really a subjective
decision, but I'd recommend when the water drops below 40

This way, it's still above freezing, but cold enough that the
fish don't really need as much oxygen. And if they haven't been
eating for awhile - they also not producing much waste to pollute
the water. Your beneficial bacteria are largely inactive at this
point anyway, so there's no use in circulating the water...


Question #3>

I have a 1000 gallon water tank set it my basement for my koi
fish, I have a bioloigical filter system for ponds up to 4000
gallons with a 25 watt uv sterilizer hooked to a 1200gph pump.

I check my ammonia levels twice aweek, at the beginning of the
week everything is fine, but by the end of the week I have to do
a 50% water change. Is this normal? Is there something I am
doing wrong, is there something that I can do so I don't have to
change so much so often?





Well Mary,

It depends on how many fish you have in the 1000 tank, and how
old your filter is. The correct way to size any filter, is
really based on how many pounds of fish you have. However, most
koi keepers and pond owners have no idea - so filter mfg's make
it easy by giving a '# of gallons' rating.

The problem with this is, if you have 50lbs of fish in a 1000
gallong pond, it's going to be difficult to keep your Ammonia
levels down with ANY filter.

Also, many pond filters are very aggressive in their ratings of
what their filters will handle, in terms of pond size.
Especially, some of the less expensive and even mid-range

Why? Because they want to sell filters, and b/c everyone seems
to over-rate their filters capacity. The bottom line is, that if
you're still getting Ammonia readings, then your filter is not
big enough.

Some things you can do to help are: Adding a biological additive
like Microbe Lift-PL to help keep your good bacteria levels high
and to help digest any decaying organic waste in the pond -
another potential source for Ammonia.

Also, cut back on your feedings (or discontinue) until you can
get you Ammonia levels under control. High Ammonia levels can
cause undue stress on fish, which over time will result in a
weakened immuse system and possibly sick (or dead) fish.

You can also use a product called 'Ammo-Lock II' which basicaly
neutralizes the Ammonia, and makes it relatively non-toxic. It's
also great for de-chlorinating new pond water...

Hope this helps.

Here are links to the two products I mentioned above:

Microbe Lift:

Ammo Lock II:


Happy Ponkeeping!

Brett Fogle
MacArthur Water Gardens

>> To view past issues of our Pond Q&A, please visit our weblog

MacArthur Water Gardens
PO Box 3628
Alpharetta, GA 30023-3628

Posted by bfogle at October 22, 2004 05:47 AM