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View Full Version : Does anyone know the best way to prevent lake freezing...


RobertT
11-29-2005, 06:08 PM
around a lift or dock. Most people don't on my lake, but a few people had some damage.

A few guys said that you can buy a little "bubbler" for a few hundred that basically uses an underwater fan to pull the warm bottom water up to the top and prevents ice in a huge area.

I just dont know where to get one or if thats the best option.

Nope...not going to pull the dock and lift out no matter what :cool:

Footin
11-29-2005, 06:15 PM
A trolling motor converted to an AC power source. Hook the motor up to the dock and run it on low. The current and water movement it produces will keep the area around the dock from freezeing.

Lottawatta
11-29-2005, 06:30 PM
Bubblers are available at west marine or overton's. I have bever used one. I have a floating boat house (30 x 32 enclosed) with two lifts in it and they stay in all winter with no damage from ice (usually a foot thick at the depths of winter).....nock on wood. But my lake is small and the ice doesn't move much.

http://www.westmarine.com/webapp/wcs/stores/servlet/CategoryDisplay?catalogId=10001&storeId=10001&categoryId=756&langId=-1&subdeptNum=11207&storeNum=5

east tx skier
11-29-2005, 06:42 PM
How 'bout a box of salt?

stevo137
11-29-2005, 06:46 PM
Our local marinas use aerators.

lake
11-29-2005, 06:50 PM
Try this link. http://www.iboats.com/products/16/39349_powerhouse_ice_eater.html

I've seen ads in the boat paper from Lake Ozark that Trico docks carries this brand.

88 PS190
11-29-2005, 07:47 PM
Here's a far idea... convert to an open geothermal heating system, groundwater gets pulled up, heat removed to warm your house, then send the excess water out under your dock, consistantly warmer than lake temperature.

You'll have to find an older system i think. Most of the newer styles send a copper heat exchanger coil down and circulate a coolant as opposed to continually draining the ground water source. Course it also keeps your well from having difficulties.

RobertT
11-29-2005, 08:03 PM
Thanks guys...

The de-ice blowers are basically just a fan. Thats what I will get. A neighbor said that he got scared when there was 6" of ice because it was going to rain....bought one....cut a hole in the ice....dropped it in....and in a few hours not only was his dock and lift ice free it was clear for hundreds of feet in each direction. Evidently the bottom temperature is usually 40+ degrees minimum and it doesn't take much of that water to melt ice.

To me, with no actual experience, I am not worried about the ice by itself. What I am worried about is what would happen if we got a rain when everything is iced over! My lake is fed by a creek/river. In a hard rain/melt the lake can raise as much as 1' in a few hours before it flows over the dam on the other side. If you have a foot of ice, and the level raises quickly its going to do some damage. I figure for a few hundred....why put the stress on my lift and floating dock? Its just not worth it.


Once it freezes hard, I will flick the switch and melt it down every few days. Worth it for piece of mind.

bigmac
11-29-2005, 08:17 PM
Thanks guys...

The de-ice blowers are basically just a fan. Thats what I will get. A neighbor said that he got scared when there was 6" of ice because it was going to rain....bought one....cut a hole in the ice....dropped it in....and in a few hours not only was his dock and lift ice free it was clear for hundreds of feet in each direction. Evidently the bottom temperature is usually 40+ degrees minimum and it doesn't take much of that water to melt ice.

To me, with no actual experience, I am not worried about the ice by itself. What I am worried about is what would happen if we got a rain when everything is iced over! My lake is fed by a creek/river. In a hard rain/melt the lake can raise as much as 1' in a few hours before it flows over the dam on the other side. If you have a foot of ice, and the level raises quickly its going to do some damage. I figure for a few hundred....why put the stress on my lift and floating dock? Its just not worth it.


Once it freezes hard, I will flick the switch and melt it down every few days. Worth it for piece of mind.


Your situation with lake level fluctuations is a little different, but around here, the damage to docks and lifts that have been left in is more likely to happen in the spring as the ice breaks up and get blown around by the wind.

wiltok
11-29-2005, 09:45 PM
How deep does the water need to be to "pull warmer water off the bottom to the surface"? My dock, at the deepest point, is about 4 feet off the bottom. Is that enough?

Leroy
11-29-2005, 10:36 PM
Marina I used last year had the Ice Eaters listed below and they worked very well, but the water was 15-20 feet deep and this is Indianaplis, where you only get maybe 6 inches of ice at most if you do nothing.

hacker
11-30-2005, 09:13 AM
Evidently the bottom temperature is usually 40+ degrees minimum and it doesn't take much of that water to melt ice.


How deep does the water need to be to "pull warmer water off the bottom to the surface"? My dock, at the deepest point, is about 4 feet off the bottom. Is that enough?

FWIW

I remember seeing on the Weather Channel a few years ago a show on how a body of water freezes. Evidentally water is heaviest at 39degF. So the surface must reach that temp then a "layer" of 39deg water will sink to the bottom. Then that process repeats until it's 39 from the bottom to the top, at that point the top layer can then be cooled down to 32 and freeze.

shepherd
11-30-2005, 10:06 AM
As long as the water at the bottom is not frozen, it is warmer than the ice and will melt it (or keep ice from ever forming) when pulled up to the surface. I too have seen the bubblers in action. They keep a nice ring of soft water around the dock/boat/vicinity.

wiltok
11-30-2005, 12:59 PM
Next question :)

I have a 100 foot dock - would 1 ice eater at 50 feet suffice or would I need 2?

Workin' 4 Toys
11-30-2005, 01:01 PM
Our local marinas use aerators.
This marina Steve speaks of is seriously worth a look. I was so surprised the first time I saw it how well this works. A huge section of the lake is water all winter. aluminum piers stay in and all, with no damage.
I was amazed.

BriEOD
11-30-2005, 02:04 PM
How 'bout a box of salt?
I was just thinking the same thing.

RobertT
11-30-2005, 04:37 PM
FWIW

I remember seeing on the Weather Channel a few years ago a show on how a body of water freezes. Evidentally water is heaviest at 39degF. So the surface must reach that temp then a "layer" of 39deg water will sink to the bottom. Then that process repeats until it's 39 from the bottom to the top, at that point the top layer can then be cooled down to 32 and freeze.

Thats true...a little more....

The density of water decreases from that temperature as you get hotter or colder. So, they are right about that and it makes sense. But there has to be more to it. Lakes freeze first on the edges. One would think that the colder water would "roll" down the bank of the lake to the bottom and the entire lake would be at the same temperature. That's not the case though. Convection properties are pretty complex in a situation like that.

Once water gets past about 4-7 degrees above freezing (varies due to impurities in the water if I am thinking right) it begins to change on a molecular level. I don't even know why I know this...but it has something to do with the hydrogen molecules shifting apart and taking up more space...therefore less density. Something about realigning at a 105 degree angle or something. That makes sense anyway. Again, by memory I might be way wrong here, but once the hydrogen molecules start to drift apart they no longer work together and begin to crystallize and ice forms. Since its less dense due to the hydrogen molecules being farther apart and taking up less space...they float to the top of the lake.

I would guess that at some point the entire lake is fairly close to the same temperature if it is shallow. If it is deep, I am guessing here, but molecular friction would prevent that water from changing with the bottom water.

Still, because ice is such a great insulator, once the lake does freeze it should begin to warm on the bottom slightly due to geothermal energy. So, I would guess, than even though at some point during the year the bottom of a 10' deep lake might be within a few degrees of freezing, that the bottom will warm up several degrees over the winter.

Lakes "turn over" twice a year because of this as most know.

To complicate things, water movement can prevent freezing as well. I have seen a lake with ripples freeze almost instantly when the wind stops. Water can get down to VERY cold temperatures without freezing if it is moving fast enough. The hydrogen molecules of different water molecules desperately want to bond together, but it does take a small amount of time for them to court each other so to speak. If they are not allowed that time, they cant bond and no ice is formed.

Wait, why did I even take the time to write this? I sound like a dork.

All that counts is that warmer water from the bottom directed at the ice or colder water at the top will stop ice from jacking up my lift. That is all that matters at this point :)

OhioProstar
11-30-2005, 05:36 PM
My parents have lived on a private lake for 21 years. They lower the lake every year to prevent damage. This protects the majority of the dock, but the forward supports are still in a couple feet of water. Twice over that time it has rained enough in Feb/March with ice still packed to lift the water level and the supports out of the lake bottom. It was a pain in the arse to fix. Most people out there remove their lift since it is fairly easy. Whatever you do post some pics when all of us are stuck inside with zero degree temps.