I only use a bubbler and have no problems. I put my barley straw over the bubbler so that the bubbler aerates the barley straw. It seems to prevent that spring bloom of algae before my plants come back. I use the same bale of barley straw for a full year. I my leave it in longer this year, just turn it upside down.

johnkr, a tiny little hole that is only an inch wide is not is not sufficient to allow trapped pond gases to escape. Thus, anyone using a ThermoPond heater will not do much good, except for very small ponds.

However, deicing your entire pond is not necessary either. So how large should the hole be? I like to keep a hole a couple of foot wide so there is adequate gas exchange for my fish.

Now that is my opinion. I am not aware of any scientific evidence on how large a hole is needed? I may be wrong and a much large hole is needed? It makes sense that the larger the surface area of open water is, the more air exchange takes place.

If you only have a 100 gallon tank with a small number of fish, a small hole might be adequate? However, if you have a large pond with lots of Koi, then you need a larger hole.

Of course, the people that sell the ThermoPond deicer make the claim that a 1 inch hole is all that is needed since they are in the business of selling it. However, do they really have any hard evidence to support that fact?

Of course, it is up to each person to decide if he wants to add more oxygen to their pond and spend the few extra bucks to make sure their fish are happy and healthy.

I would rather be on the side of caution when it comes to the lives of my fish which are my pets and my responsibility.

i made a post here awhile back asking if there was any kind of heater device that can keep my whole entire pond open and heated through out winter. that would be awesome having it snow outside and keeping my pond at 60 degrees or so. however with the replies it didnt seem economically possible.
i got 1/4 of my pond open now, maybe it could get as much as half which would be great.
the more surface area open the better

John, I use a 450 [US] GPH pond pump that is located in my bottom drain settling tank. With that I pump the water from the settling tank, through a half inch hose, eight feet to my pond, where it moves the surface of the pond and returns to the settling tank via the bottom drain.

Usually the hole can vary, from three feet long oval shaped opening, down to one foot opening, depending on the month and temperature.
The pump only consumes 45 watts, so it is very cost effective and a great savings on energy, for myself and others who are interested in saving energy and helping their environment.

Through many winters, this method has worked out satisfactorily for me and my 2000+ gallon pond inhabitants. My fish, I believe are happy, but to tell the truth, I've never seen them smile, winter or summer, for that matter, but I know they are healthy.

Since pumps can fail, I have a 1500 watt, model 7521 API, floating stock-tank de-icer, as a stand-by, just in case.
My ponds are covered over all winter with a translucent tarp, laid over a simple two X four frame and that keeps the cold wind from blowing over the surface of the water, thus helping to limit the ice build up.

In my salad days of pond ownership, I did not cover the five, inter-connected ponds, I had at that time, but used the 1500 watt de-icer, which was more on than off all winter long, and very expensive on energy costs I found.
That is when I started researching other methods of venting a garden pond in winter. Eventually settling on using the small GPH pump, over the use of an electrical powered de-icer.
At that time stock-tank de-icers were the only thing available on the market as far as electrical powered de-icers are concerned.

In the FAQ's on this site, DRH of Vermont, submitted an excellent article on winterising or more aptly, venting ice covered ponds.
David uses the aquarium air pump bubbler method to great success, in Vermont where winters can be a tad chilly to say the least.
He does refer to other methods used for venting a winter pond, in this article.

As has been reported on this form, many times over the years, there are people who do not vent their ponds at all and say there is nothing detrimental happened to their fish or other creatures.
I do not advocate that idea, I prefer to have a vent hole open in the ice, but I do not believe it is at all necessary to de-ice the whole pond to accomplish the venting/ gas exchange.
I have only ever read of that being suggested as a better way of doing it, here on this form.

I believe that de-icing the whole pond is over doing things as far as venting/gas exchange.
People may do it for ascetic reasons, because they like to see the water open all winter or for whatever reasons they may have, that is their business and their right to do so. But in my opinion and that of many pond keeping experts, it is definitely not required, in the average garden pond, to keep the fish healthy or smiling for that matter ;-)
"Horton"

.

John the size of the hole is in direct relation to the amount of debri and fish in the pond. The more debri and more fish in the pond the greater the size of the hole has to be. My koi pond I keep heated to 60 degrees during the winter in Chicago. But I would not suggest doing this unless the pond is covered. I do not run the waterfall in the winter. I use natural gas to do this with a cost of under a hundred dollars for the winter.
Mike

Bigger is better, but small is OK, and many report no opening at all. Gas can move through the smallest of spaces. Try sticking a pin in a balloon and see what happens:-) LOL (I am not comparing a pond to a balloon BTW)

The water is cold and the fish are not eating but sitting on the bottom. Same for the frogs. Ice (and snow) on most of the pond acts as an insulator.

IMO - it would be a waste of money to heat a pond all winter to have no ice at all, especially in really cold winter zones, unless there was a valid reason (and I can't think of one just now), but we all choose how we spend our money.

It is one of those things people never agree on to any extreme, but there is a large concensus that would agree any size opening is OK as opposed to no opening, which conversely the opposite would be, the whole pond open. I've read that the winter and cold water is beneficial to goldfish.

CT

Transferred from.
RE: got stock tank heater, help

Posted by drh1 z4 VT (My Page) on Wed, Feb 21, 07 at 19:52

Air Exchange In Your Pond 101
Judging by several of the comments there is a bit of confusion on what is occurring with gas exchange into/out of your pond. I apologize for the length of this - feel free to not bother to read it (except for Rule #1).

Rule # 1: If you have a pond and youve been doing something that works for you and youÂre happy with it....forget everything else and stick with it. Do not read any further.

All other Rules: The following are "things" that influence the RATE at which a gas will go into or out of solution:
a.) Water temperature - the colder the water the more of a gas can be held in solution... and therefore the higher the saturation concentration (commonly referred to as HenryÂs Law and is also dependent on the concentration of the gas in the atmosphere as well as the temperature); the colder temperatures will decrease .... somewhat.... the RATE at which a gas will diffuse through the water and into the air or from the air into the water.
b.) Turbulence and mixing. The RATE at which a gas moves into or out of the water is controlled, in general, by a very thin film of water molecules right at the surface of the water (commonly referred to as FickÂs Single Film Model  as one example). The thicker this film the slower the RATE at which the gas can go into or out of solution. The more mixing or turbulence you provide the thinner the film. Therefore, if we arenÂt getting enough gas (oxygen, for example) into the pond we mix it, let it cascade down a waterfall, use a bubbler.. all of which cause the water to mix and "refresh" the surface and reducing that limiting liquid film thickness. The same applies to getting gases out of solution.
c.) Surface area. Often people assume that this is the only variable or parameter that influences gas going into or coming out of solution. While it is a very significant factor it is not the only thing that is relevant. Obviously more surface area is better but there is a point of diminishing returns when there is so much surface area that there is little significant increase in the RATE of gas transport. When we use a stock tank heater or a pond heater the surface area is obviously the amount of clear water surface that we see. However, when using a bubbler the surface area is NOT the size of the hole from which the gas is exiting but rather the TOTAL surface area of each and every bubble that is produced under water. So if your bubbler is putting out 4 liters of air per minute, with an average bubble diameter of say an 1/8 inch you will be producing a little over 80 square feet of surface area each minute. The finer the bubble, the more the surface area. This is why bubblers are much more effective in promoting gas exchange than something that opens up a 2 foot or 3 foot hole in your ice (~9 - 27 square feet).

So what size hole should one have? There is no specific answer for this nor can there really be one. It depends. If you have "a lot" of fish in your pond then youÂll need more surface area for gas exchange than if you have one comet in your 2000 gallon, lake. Secondly, water temperature also rears its ugly head again. As a general rule of thumb (which means itÂs not accurate at all!!) biological activity doubles for every 10 degree C change in water temperature. So if your pond is at 2 degrees C versus 12 degrees C then the amount of wastes produced and consumed will be significantly lower than for the higher temperature. This means that if you intend to keep your pond a nice, toasty 45F all winter with your pond heater, immersion heater, solar heater, backyard barbecue grill, etc. then youÂre going to need a significantly larger amount of surface area than the person that lets the pond sit close to freezing. The assumption that your fish huddle around your heater holding their fins out for the warmth is a bit too much anthropomorphizing!

Being of New England stock and heritage means that my DNA is such that I donÂt like to part with my ÂLincolnsÂ... and I mean the one cent variety. ThatÂs why I use a bubbler here in zone 4. My pond is pretty close to 3000 gallons (as a guesstimate) with a depth of only 3 feet. IÂve had ice as thick as 18" on it (about 2 years ago if memory serves me correctly). Essentially all of my fish survive and appear to be well each spring. Sometimes there are a few less of the smaller comets but I happen to know for a fact that the Koi will munch on them over the winter. All of this with nothing more than a 4.5 watt aquarium air pump! My electric bill never sees the difference. The URL below should give you access to a pdf file that was mentioned by Horton...it describes what I use for a bubbler system. I would not recommend it for small ponds in zone 4.

ThereÂs even more that we could discuss but IÂve obviously babbled on long enough.

ÂDavid

Sam, you wanted to read an expert opinon, well that previous post by David, is exactly that.
Enjoy!

"Being of New England stock and heritage means that my DNA is such that I dont like to part with my Lincolns... and I mean the one cent variety."

That is funny! LOL

Thank you Rhodyman, Horton and Prof. David for adding some of your practical experience to this forum. Hopefully some members and readers have learned that a problem can have many solutions and some are better then others.

A stock tank heater will absolutely provide an opening in a frozen pond and allow gases to escape. A larger opening will allow more gas to escape over a given amount of time then a smaller opening. If your car runs over a nail it may take an hour to loose most of the air in a tire. If the same tire is punctured by several nails, it may go flat in a matter of seconds. Either way you have a flat tire. Either way the gas escapes.

I see no evidence, nor has it been my experience, that a smaller hole will place fish or other pond inhabitants at a greater risk. Drh1 has made a strong case in support of a bubbler releasing more gases through a smaller hole then would be released from a larger hole with no bubbler. Like many on this forum, I have been using a bubbler for many years. I do own several heaters and do use them during extreme temperatures.
Everyone has their own opinions, but I would have a hard time arguing the benefits of using a stock tank heater all winter over the use of a bubbler with the heater as a backup. I would absolutely yield to the stock tank heater if I lived in a colder climate. As far as oxygen, the bubbler would certainly provide a better environment for hibernating fish and allow more gas to escape.

Sometimes the less expensive methods are the better methods. Spending $150 a month on energy costs is fine if it were the only solution or the best solution. I see some evidence that it is not.

The 2007 ponding season is almost over here in New England as we prepare for the big freeze by sinking our plants and making our dormant fish friends and frogs comfortable for 4 months (late Nov to late March). I'm in my 7th year of ponding (small pond, 9 fish, numerous frogs).

The first winter, I tried the bubbler to keep a hole open for gas to escape per Pond Forum suggestions. The bubbler worked fine until mid-January. Got up one morning and my pond bubbler had the most beautiful ice sculpture covering the small hole. Being new to ponding, I panicked instead of going to the pond forum for urgent advice. I got an AXE and trudged knee deep in snow and proceeded to chop the ice. Well, I then made the MISTAKE of telling the forum what I did to get the hole open thinking I saved my fish from instant death and forum members would applaud
my heroism. W R O N G

The response was "you horrible person" How would you like someone entering your home with an axe!?" "You just caused your fish to go into major stress from the noise of your axe breaking ice!" OMG! Being new, I just knew my fish would be belly up in the spring with frozen stressed out shock in their dead eyes and I would be turned into the pond police for cruelty to fish/frog section#119. After reading the responses chastizing me for axe rescue, I made a mad dash to the farm supply store and purchased a stock tank heater. It has worked perfectly going on 6yrs and I've yet to see a significant increase in my electric bill. My heater only turns on when the water temp falls below 45' so it's not running 24/7.

My humble advice, if you live in the NE and/or experience harsh winters.....get the stock tank heater. Now every winter season, I watch my original fish with their grown babies circle the heater and play poker for 4 months. The fish family has been taken off the Zoloft treatments I gave them after the unintentional axe incident and they are drug free.
http://s176.photobucket.com/albums/w180/alyceskis/?action=view¤t=PONDBLIZZARD.jpg

Ooops...copied wrong Photobucket for fish Family Home in CT Winter.
{{gwi:184864}}

Alyceskis, you're funny AND helpful. I hadn't seen this thread when searching for winterizing info.
Vanessa