Pond freeze-over time limit 1/17/08
Hello Crew,
<Mark>
I live in the Chicago area and have had a 2500 gallon pond about 26' x 18' for several years now. There are about 12 medium sized Koi (~5-10" ea), 5 medium sized assorted goldfish (~4-8"ea) and probably 20+ small (~1-2" ea) goldfish that were the result of some breeding activity last year.
<Okay>
I use a standard Farm Innovators Floating Pond Deicer to keep a hole in the ice over the winter. Yesterday when the weather returned to the cold temps the pond froze over but I noticed the heater seems to have died since the last freeze-over and now it is frozen in the ice. I will replace the heater but in the meantime, how long can I leave the pond frozen over without fear that the fish will be affected? Do I risk carefully breaking the ice or is it better to be patient and get a functioning heater in as soon as I can?
<Could run out of oxygen... and/or if it freezes to the bottom... and BE VERY careful re walking, striking the ice cover... Deadly>
Thanks for a fast turn around on this as the time is ticking!!
Mark
<Read here: http://wetwebmedia.com/PondSubWebIndex/pdmaintwint.htm
and the linked files above. Bob Fenner>

Stinky pond, winter -12/22/2007
Hi,
Hope this is not a redundant question...
My parents bought a house (Portland Oregon) this winter. Prior owner had a pond installed with waterfall, do not know if they ever kept fish in it but they did have plants. Suspect they had chemicals in it while the house was on the market 6 months to keep it clean and avoid maintenance, it has a suspicious lack of algae and no plants, snails or vertebrates. I am guessing it's 800 gallons at least and over 4 feet deep. The waterfall and filter were randomly turned off for days, weeks at a time over the last half year, and leaves accumulated. The water has a hydrogen sulfide smell to it. The person turning the pump on and off did not know to drain the stale water from the filter before turning it back on, so it got shot back into the pond after periods of anaerobic nastiness. Suffice to say it looks great but the smell is not so hot.
So... if the rotting leaves are sieved out, filter cleaned and waterfall running, could the stinky water "clear up" and be safe for new livestock this spring?
<Likely so>
If not would carbon help?
<Mmm, not worthwhile in pond-volumes...>
Or should we drain and clean it and start over?
<I would not try this till Spring has "really sprung">
Draining would be complicated because there is nowhere to put the water except on the ground, and it will then drain in to the neighbor's yard.
<Mmm, look for a sewage clean out (a four inch threaded cap line...)>
That probably wouldn't go over real well, especially as the ground is already saturated and marshy. My Dad is also hoping we can avoid draining it because he is worried about the water bill.
Advice?
Thanks,
Kate B
<Wait for now... Read here: http://wetwebmedia.com/PondSubWebIndex/pdmaintwint.htm
and the linked files above. Bob Fenner>

Pond liner exposure to winter weather 10/14/07
We drain our 4000 gallon pond and would like to leave it empty for the winter. We want to leave it empty and then clean and refill it in the spring. All fish and plants have been relocated to another pond.
Will this cause any damage to the pond liner since it will be exposed to cold central Illinois weather?
<Mmm, likely not IF this liner is of butyl/rubber... EPDM or composite make-up of adequate thickness (30 mils or more let's say)... I might throw some straw on it to prevent some possible damage by accrued snow, water/ice. Bob Fenner>

Re: Pond des., pb.  10/3/07
Thanks very much for your prompt and thorough response. You said you are about to be out of net reach so perhaps this reply is too late but, here's hoping...
<Here for another day>
The only point I didn't understand and would love to hear more about was your comment as follows from my question about the currently built 45 degree walls
>The contractor left long sloping edges that I don't like very much. They slope nearly 45 degrees around the shallow end.
... <Mmm, yes... not good for maintenance, but better to avoid
having the basin crushed, pop-out during coldest weather>
I am not familiar with the concept of Basin crush, pop out from cold weather.
<In areas where the ground freezes down a bit, and there is a good deal of water, lack of compressibility to the soil... the expansion with freezing can indeed crush the sides, even "pop out" the basin or swimming pool...>
I don't want to assume the previous contractor was totally looped, if he had some wisdom for this Denver climate I want to understand it before I tear it down. Are vertical walls more susceptible to bulge later from frost heave than are degrees of slope?
<To some degree, yes>
If so perhaps I will have to research local builders and see if I can get an idea what works locally.
<Mmm, have been to Denver... and see on the Net that the area does not usually get much of a "freeze"... the micro-climate can be of sizable influence as well... if there are large trees, structure near by... this will reduce freezing as well>
I will start contacting local building firms in the mean time (in case yo are away for the time you thought you would be away and cant respond to this follow up) and see if I can learn more about this concept.
Again, my thanks for your time to reply.
David Groover
<Glad to help. BobF>

Re: Pond des., const. for cold weather  10/4/07
Ooops, I have another question already. Well, same as before, if you are still around ... and thank you - again.
<Welcome>
Yes, another day, just go your second response, much thanks.
Yes, Denver is really not that bad in the wither. But it can definitely hit below zero temps for periods of time. Last wither was blizzard after blizzard and weeks and weeks of below 10 degrees, a relative rarity but these are changing times for the weather so one can't tell for sure.
<I see>
I want to know about building with winterizing in mind just because this has become my project and I want to build a good reputation. And that usually comes from building good ponds from a viewpoint of construction, beauty, and maintenance planning, and being good at timely delivery and customer care.
<Good characteristics>
This is Denver where it can get very cold in the winter. You also have quick thaws as the sunshine is very intense here. Therefore one would assume people would want to run their water features year round here. I built a patio water feature for a friend last year in Colorado and she kept it going all year. I asked her to turn off the pump when the water had frozen and it was a very small line, easily repaired if burst so I didn't worry. The pump sat in the feature so it never got solid with ice and I didn't worry about that either.
<Okay>
But now with this size of project and having had to dig up many pipes back east that had broken (the joy of leak detection) I am certainly thinking ahead as to how I want to design this. Both for practical reasons like, is the back-flow valve I would put in what I will likely use, a bio filter, is going to allow me to drain off the water that was raising out of the pond to fill the bio filter, and for potential repair work. Should I install a bleed valve somewhere near the outtake line from the pond for winter clearing of standing water in a pipe before a freeze?
<That or insist the folks leave the system running year-round... this volume, shape should resist freezing... if so>
Or, does water always seek its own level so I needn't worry as it will just reset to the level of the pond anyway?
<Mmm, no... some systems have to be drained... Otherwise other mechanisms employed that resist freezing>
Or, do I use a larger diameter pipe, more than the flow volume, so that when water does start to freeze and expand, it has a little room to move as it were? Is schedule 40 PVC better than the consumer grade PVC as it is a stronger PVC if I am at all worried about freezing?
<Mmm, no... still have to worry regardless>
It seems to me that if I am building a large system like this I should over-build it in a way that I shouldn't have to make the homeowner worry about rushing home to turn it off if there is a freeze warning. Seems kind of silly doesn't it? But I appreciate being able to ask the question and to be reassured.
<Again... I would leave the circulation going continuously>
And this is probably somewhere on the site so sorry to ask but as I have your attention, what is recommended as a depth for water carrying pipes when there will be a freeze? I expect when I dig I will remember as I used to do it so often. Perhaps 12 inches?
<Maybe>
You asked me earlier what the homeowner wanted? Amazingly, he seems to not have discussed this with the former contractor.
<Or vice versa...>
He wants plants and fish and the water fall. He has some dogs which will probably go swimming. I warned him about this as you a are probably already aware, critters sharp claws and EPDM liners don't usually get along very well for very long.
<Errr, I would NOT make a liner-only basin of this size. We installed such features for years... but with shotcrete, concrete and reinforcing mesh over the liners...>
He didn't seem to care though. Therefore I envision this as getting it to the finish line ASAP with winter just around the corner with an eye to good future maintenance in my construction techniques. I see a good design made better but not an overly perfected look to the finished pond as in Japanese garden (which I love) or other forms of more formally prescribed beauty. I envision more of a Buddhist "I am one with nature" beauty that won't die all together form doggy dipping but will also be a part of a natural Colorado canyon landscape idea.
Thanks very much again.
David Groover
<I'd read a bit more before committing to this project. Most all my pertinent efforts are posted here: http://www.wetwebmedia.com/PondSubWebIndex/Pond%20Sub%20Web.htm, though some occur with better graphics, editing in books, manuals.
Bob Fenner>

Sick Koi?  – 03/09/07
Hi,
<Bonita>
We have had our koi pond for just over one year.
When the ice thawed about 2 weeks ago, it started getting full of stringy moss.  
<Seasonal... to be expected... and a note to all... I would NOT fool with a pond this early out of the "cold season">
The koi have been kind of dormant (not moving around much) which seems to be the case whenever the water starts getting colder (going into winter).
<Yes>
Anyway, one of the koi was particularly dormant and seemed to have moss growing on it.
<!>
Now the rest of the koi are moving around a lot, but this one has a big patch of green on its back and a small patch over each eye.  It looks just like the moss (same color and looks stringy).  My husband picked the koi up and rubbed his thumb across the green patch on its back.  It didn't come off at all and he said it felt really slimy.
<Mmm... healthy koi, pond fish... are slimy... not "dry"... but not "too" slimy either>
Can you tell me what this is and if there is anything we can do about it?
<Likely nothing... really. I would leave this fish be... and if you do "anything" with the pond... do it s l o w l y>
I have been trying to find information, but everything I read about fungus and other things seem to be white or red in color.  Also, I have read something about putting salt in the pond and someone told me I could treat the fish with salt???
<I would not at this time of year...>
Any advice would be greatly appreciated.
Thanks!
Bonnie & Rusty Wilson  
<You should read... here: http://www.wetwebmedia.com/PondSubWebIndex/Pond%20Sub%20Web.htm
scroll down to the tray on Pond Maintenance... the articles by myself... and the related/linked FAQs files. Don't fool with the pond or livestock... until it's much warmer, consistently. Bob Fenner>

Koi additions   1/12/06
HEY THERE Fellow enthusiasts!
<There you are Tom... long time, no chat>
A couple of years ago, I built a large (to us anyway) liner pond (Thanks for the help Bob!).  It is approximately 3600 GAL or so.  It has been doing wonderful and the fish are happy and healthy.
But here's the question.  A friend of mine is moving and can't take his (6) koi with him.  He wants to give them to me for my pond .  I feel there is enough room in the pond for them (only 5 fish right now) but am worried about adding fish in the winter.
<Mmm, yes... a tough time to move>
Will the bacteria be able to reproduce rapidly enough to keep up with the added load in cold water?
<Actually... likely so... there is very little excretion of such in cold temperatures... the big troubles come about from the actual fish being moved... more psycho-social than physiological>
  I live in Northern VA and, although winter hasn't truly visited us yet, the water is around the upper 40's (we stopped feeding in Nov when it dropped below 50).
<Mmm... I take it all the fish... yours and theirs are outdoors... moving the koi expediently, switching water back and forth to acclimate, provide oxygen... not raising water temperature much in transition... should do it here>
If this is in any way risky, I have no problem housing the new fish (around 6 - 8" each) in the basement in a 100 GAL stock tub with filter until the Spring.
What are your thoughts?
<Better to mix in with your existing fish IMO>
Thanks so much for all that you fine folks do!
Tom (The Tool Man)
<Be chatting, Bob Fenner>

New pond... design/iatrogenic problems   12/3/06
Hi,
<Hello there>
I've done a bit of research but have not found the answer to these questions.
We've recently installed a small pond between 2 patios in our back yard in the Pacific Northwest.  It measures approximately 8' x 12' and is 20 inches deep
<Mmm, too shallow... will be too variable in temperature to be stable... hard on livestock>
with a thin layer of small gravel in the bottom.
<Is this intended to be a biological system? You don't want gravel at the bottom... as you will learn>
It also has a small waterfall for circulation.  We've added pots of water plants, lily pads, floating lettuce and hyacinth and some others.  We bought 12 goldfish and they seem to be enjoying the pond immensely.
<You will need to bring all this life "in-doors" during the winter months...>
  My first question is about feeding.  The pet store clerk and the water pond clerk both said that they don't feed their fish.
<See WWM re... no feeding during times when temperatures dip/stay below about 55 F.>
It increases the nitrate levels in the pond, plus the stores sell them really fast.
<...>
  So-do we need to feed them or will they feed on the plant material and what ever algae grows in the pond?
<See WWM...>
My second question involves our new pond inhabitant.  A rather large bull frog just appeared yesterday.  He seems to enjoy the pond too.
<And your fish>
Because it is the end of September, I'm wondering if he plans to hibernate here.  As I mentioned, the pond is only 20 inches deep with a little gravel.  Is that enough depth?
<Not enough...>
  Plus there is no mud for him to burrow into.  I hope he's had his fill for the year, because I don't want him eating my fish.  
Should we "encourage" him to leave?
<I would, yes>
Any help you can give is much appreciated.  We're new to water features and want to do it right.  I suppose we need to figure out about testing the water too.  What is the correct ph balance we should try to maintain?
Thanks for your help.
Sandy
<I strongly encourage your reading of what is posted on ponds on our site: http://www.wetwebmedia.com/PondSubWebIndex/Pond%20Sub%20Web.htm
From the top down... including pond design... Yours will be problematical due to its size, shape, the gravel... Bob Fenner>

Overwintering Koi in a cold locale   9/19/06
Hi:
<Hello there>
I have a rather small pond about 5' x 4' x 20" - I am worried about my beautiful young koi.  There are 3 - 7" koi and 4 babies that are about 1" each - they were born this year.  I have been told I can leave them in the pond if I use an aerator to keep water moving or a deicer.
<Mmm, no... unlikely... too much chance this volume, size/depth basin will freeze all the way>
At 20" I am afraid the water will freeze solid.  Should I buy a 100 gal Rubbermaid trough (or bigger) and move the koi into the garage for the winter.
<Yes, I would>
We are going to expand the pond in the spring and will make an area that is at least 3' deep - I know they can survive throughout the winter at that depth.
  If the garage stays between 20 and 30 degrees throughout the winter, would the koi be better there and then what do I need for the trough.  
<Store it... incorporate it into the pond/bog filter...>
The aerator - do I need to run a filter - I have no idea what to do.  I need help
<I would run a large sponge filter and a Tetra Luft pump to operate it... Please read here: http://www.wetwebmedia.com/PondSubhttp://www.wetwebmedia.com/pdmaintwint.htm and the linked files above, and: FWSubWebIndex/spngfltfaqs.htm
Bob Fenner>
Thanks a million
Jacque

Re: Overwintering Koi in a cold locale   9/19/06
Thanks for your response.  I went to the web site but I can't identify the large sponge filter you are referring to in the e-mail can  you be more specific?
<Mmm, let's see... http://www.pondbiz.com/home/pb1/smartlist_106/tetra_pond_filters.html>
Also, will a 100 gal tub be large enough.
<Should be... with a cycled filter in place, careful to no feeding when temperature is below 55 F... Bob Fenner>
Jacquelin A. Moody

Pond Overwintering, not reading   8/19/06
Ok well I live in  Pennsylvania where it is pretty cold and the pond will freeze. How deep does it  have to be.
<Mmm... depends on what you intend to keep in it, where it's located relative to "structure", whether you intend to employ countervailing strategies to prevent it freezing over/all the way to the bottom... 4 to 6 feet likely...>
Also is there any specific brand of food I should feed them or what  should I feed them to get their fat up for the winter.
<Please read here: http://www.wetwebmedia.com/PondSubWebIndex/pdmaintwint.htm
and the linked files above... Bob Fenner>

Pondfishes in the GWN  3/3/06
Hello
I am thinking of setting up a small outdoor pond - 180 gallons - which contains no heater and a basic filter.
<... likely too unstable at this volume...>
I am located in Nanaimo, British Columbia, Canada.
I have a couple of questions:
What type of fish would you suggest?
Can they survive the winter?
<Perhaps some of the local life...>
What happens if the water freezes in the pond?
<If all the way down, fishicles... See WWM re ponds please: http://wetwebmedia.com/PondSubWebIndex/Pond%20Sub%20Web.htm
See all those blue file names? They're links... Bob Fenner>
Thank you
Pat

Over-Wintering Goldfish  11/30/05
I saw one post where someone wanted to bring goldfish in to an aquarium. I live in zone 7 and want to bring mine in to a tub of part of the pond water and the water lilies. In the spring we'll be constructing a slightly bigger pond because my current 3' diameter (round) by 18" deep is splitting. This year at the beginning of spring, we dug into the mire of this small pond and found the 2 fish alive (surprising to us) and lots of dead frogs. Will the fish be okay in my basement in a tub until spring? Thanks!
Tammy
<Goldfish are very hardy. They should be fine. Just make sure you do regular water changes and feed very lightly. Don>

Pond water in the winter  11/23/05
Mr. Fenner:
<Jarvis>
I have one question that I'm trying to get the answer to. Recently, the area that i
<I>
live in is getting cold, and the water temperature of my koi pond is remaining at a constant 10 degrees Celsius( 50 degrees F). It is this problem that the air is colder than the pond water, and the water just keep vaporizing and escaping. Do you suggest that I add in more water? I would appreciate your response. 
A Koi keeper, Jarvis
<I would slowly add more new water (a trickle) here. Making sure you remember the source water is running (to remember to turn it off). Bob Fenner> 

My pond goldfish... winter maint. 10/31/05
I am new to this (just built concrete pond this summer). Do they need any food or plants when temperature is in 40s at night? 
<Mmm, generally not>
Wait until spring to start feeding them?
<Yes... till the water is consistently above 55 F.>
I have been told there are no plants for the winter for outdoor ponds. True?
<In a manner of speaking, yes. Please take a read over our site re Pond Maintenance (particularly seasonal) and feeding. Bob Fenner>

Moving goldfish indoors 10/25/05
It's getting cold in Minnesota and I'm preparing to bring 3 small (2 1/2" - 3") goldfish indoors for the winter.
<good>
The outdoor pond is minimal size (a gift) about 90 gallons.  I have a10 gallon aquarium with a filter, Water (conditioned), gravel on the bottom (10 pounds) and a couple anacharis plants. I'm concerned about making the change without killing the fish. 
My indoor water has stabilized over 2 days to about 70 degrees. The outdoor water temp is about 50 degrees. The indoor water has nothing added other than the conditioner. Can I add some of the clarifying bacteria inside, that I used in my outdoor pond? It seemed to work very well outdoors. 
<the goldfish should be fine with the new setup, but you may want to add some of that clarifying bacteria...it works pretty well in my opinion>
I know the trick of putting them in a bag with water from their current environment and floating it in the new environment.
<good, make sure you acclimate them well, pH, temperature changes are very stressful on fish!>
The pond has caught a lot of leafs this fall and has become a very light brown, like very thin tea. I'm thinking I would rather not mix it with my nice clean aquarium environment. Any trick there? 
<No, do not put any foreign objects into the indoor aquarium>
<<Huh?>>
Any other advice would be much appreciated. I am a complete rookie. The outdoor pond was in operation only since early August.
<I think you are doing fine, just get them inside before they freeze up there!!!!, IanB>
<<Expect that when the fishes are shifted to water so much warmer they may begin to display breeding behavior.  MH>>

How do I fatten my koi up for winter?  9/3/05
Hello, I'm lacking some knowledge about how to prepare my pond and koi for
the winter. I know that i would have to fatten my koi up for the winter,
just like squirrels do before the snow comes. How do i do this and what else
do i have to do?                                                                             
           Thank you!
<Mmm, there are a few things to do in anticipation of cool/er weather. Please read here: http://www.wetwebmedia.com/PondSubWebIndex/pdmaintwint.htm
and the linked files above... and for koi nutrition: http://www.wetwebmedia.com/PondSubWebIndex/pdfishfeeding.htm
An ongoing process... Bob Fenner>

Moving goldfish indoors for winter 8/17/05
Help me....... please,
               I'm losing sleep and winter's comin.  We have a wonderful
garden pond that has roughly 20 large goldfish, 6 shubunkin, and 15 multi
colored babies that survived the breeding and eating season.  I've come to
the realization that I have to bring all of them inside to enjoy over the
long Minnesota winter.  Would either 2 150 gallon or a single 300 gallon
tank see them through the winter?
Joann
<Yes... depending on how "large" is large, about this volume should do... you might save some money by looking for Rubbermaid troughs... and investigating filtration for these on WWM. Bob Fenner>

Pond construction question 7/13/05
I am building a semi-raised pond eight foot by twelve foot, roughly two and a
half feet deep.  I am starting out with a footing 5 1/4 inches deep by 8
inches wide, reinforced with 1/2 inch rebar horizontally and vertically.  I am
then planning on placing one course of 8x8x16 hollow core concrete blocks.  I am
capping the pond with concrete pavers probably two courses. The footing is
being poured on top of the existing grade and properly leveled.  The raised
portion of the pond will be surrounded by a flower bed which i hope will solve the
problem of grass clippings and leaves.  My question is if there should be any
concern about frost line with the poured footing and if i should be concerned
with it cracking or being damaged.
<Mmm, yes... if the ground and air get/stay below freezing for long...>
I will have a EPDM liner and underlayment
inside the concrete block and form. I live in New Jersey, USA. Any information
or help would be greatly appreciated. Everywhere i read and research has not
mentioned anything about this concern. Thank you for your assistance.
Dan
<There are a few ways to thermally heat and insulate winter ponds (posted on WWM)... I would use a thermometer daily... or plan on draining the pond, plumbing, pump... during this time. Bob Fenner whose wife is from Garfield>

NOT moving pond livestock during the winter
I have a small pond with approx 3-7 yr old Koi 2-4yr old and 3-2 yr olds. My
problem is, we ended up buying  house a lot quicker than I imagined. Now
it's full blown winter and I am scared to move my fish but I am not leaving
them behind. What can I do??
<I'd "make a deal" with the new owners... to keep all going till the weather has warmed into Spring AND you've had time to design, build-out quarters for them at your new digs... there are designs for liner ponds on WetWebMedia, and ready-made pools, filters...>
I don't want to shock them. I have a pond
heater running and they love it but I don't know if it's keeping it warm
enough to move them.
<You are wise here... I also would NOT move this life>
They are somewhat active and do come up to the surface
occasionally. I plan to move them into a large container indoors until I am
able to get their new home setup, stabilized in spring. What is the best way
to move them from winter weather to indoor luxury living? Thank you for your
help.
D. Houghton
<Do NOT do this... their metabolisms cannot take the rapid change... may appear fine for a few to several weeks... will likely die as a consequence. Bob Fenner>