Pond Boss Forums AERATION Systems questions Clear my frozen air line?

Before the hard freeze came, I set up a homemade aeration system in my pond. I used a weeping watering hose coiled in a loop, nylon tied to a brick and connected it with 50 feet of 1/4" air line. The compressor is located in my well house about 10 feet from the pond. The line is barried about 6 inches below the surface until it enters the pond. The system worked great until we had a warm spell a couple of days ago. I didn't weight the line so it has loops that got frozen in the surface ice.

Upon my daily inspection I found no surface disturbance so I thought the compressor had gone bad and swichted it out with another, which worked for about 3 minutes then stopped. I then reinstalled the original compressor and it worked, after a very slow start making bubbles, and then the bubbling stopped completely and you could hear the compressor straining, obvisouly a block age.

Any suggestions on how to unblock the ice from the airline?

Try adding denatured alcohol in the line and let it set for 5-10 minutes and then put some pressure in the line. RV antifreeze will work also but slower. dry gas like HEET will thaw a line quickly also. CAUTION >>>>>>> If you add a flammable like denatured alcohol, or any meth type product be sure you do not have your relief valve near any open motor windings or electrical outlet. Your relief valve may open prior to any blockage being opened and spray liquid or vapors. NOT GOOD !!

Scruffy:

I suggest when the ground thaws in late Spring, early summer, that you replace the 50' of 1/4" air line with 1/2" stuff. If an area does condense and freeze, there still should be room for the air to flow, plus you compressor will like it a lot better.

For airline driers to work, they have to reach the ice and it sounds like your blockage is in a high spot. Wait till you have a bright sunny day to melt it.

A 1/2 inch line will not help I don't think. I have a 3/4 inch line that keeps freezing from condensation. The line comes out of the barn 5 feet off the ground and slopes down to the ground in 25 feet. This 25 foot run freezes solid every 2 weeks. I put in two valves at the compressor so I can dump alc. in the line when the pressure climbs on the gauge.

I'm probably jinxing myself, but I've never had an airline freeze. But, the compressor is in a plastic doghouse, outside in ambient temp. air. Once started, I leave it running, so maybe that's part of the success. I use 100' of 1/2" line, this year about 25' or so is out of the pond.

My airline did not freeze once last winter and I can't figure it out. The only difference is last year i started it in february and this year i have had it running full time. My barn is insulated but not heated but there would be temperature differences so i don't know

The compressor is in a wooden dog house like structure along with a small well pump. The heat generated by the compressor keeps the house warm. I buried the line in a sleeve of poly pipe insulation from the house to the pond to protect it and hoped it would keep the line from freezing. I really should put an air release valve and gauge on the line also.

We are having a rain day today, a break from the below freezing we've had for the last couple of weeks. I'm sure it has to be somewhere in a high spot locked in the surface ice, like Rainman suggested. I should have weighted the length of the line to where it enters the pond. Wouldn’t the pressure of the air push the alcohol to the blockage?

I’m thinking, about putting on an inline antifreeze device, but the ones I’ve seen are pretty bulky and wouldn’t fit in the well house. I’m a DIY guy and I’m trying to figure out how to set up a flow valve using back pressure, in a small package. I don’t think I’d need more than a quart of alcohol in the reservoir for the winter.

Pressure won't move it---you will need air flow to do that.

Went out and picked up a pressure gauge and installed it on the compressor after the rain let up. I'm getting a reading of about 38 psi with the valve wide open. The pond level has come up about 4-6 inches and I'm hoping the ice blockage is loosened.

After running the air for a while I began to notice small bubbles trapped under the clear ice forming a larger bubble. Waited for about 10 or so minutes and had a break through of air to the surface.

Then a funny thing happened, the bubbling stopped. Then they started again, on and off, while the compressor still had good pressure. Couldn't figure out what was happining until I noticed, through the clear ice, bubbles forming in another area and working their way to the open hole. There is no water movement in the pond other than what the air does so it must be the contours under the ice. I watched this happen for about half an hour and left because my feet were frozen. I sure hope I don't get the freeze up again. If I do I will try the alochol treatment.

Scruffy is your pond close to full yet?
Also do you run the aerator full time to keep an opening in the ice, we've got some real cold weather coming in tomorrow.

The pond is still down, about half pool. The aeration was going 24/7 until we had an above freezing day last week when the moisture must have gotten into the line and caused the freeze up.

Got it flowing again today with the rain and maybe the raise in the pool allowed the hose to come out of the surface ice? When I left it was bubbling through off and on.

The bubbler is in the deepest part of the pond, now about 4-5 feet of depth. I've been reading about super chilling the water in the deep areas is not good for the fish. At this point in time I have no choice but to leave it where it is, and wait until spring to see if the trout make it.

I have some concern about putting anti freeze in the line with trout in the water, so I hope it dosen't freeze up again.

Scruffy,

Don't worry about superchilling the trout. I've never had that problem with mine.

Scruffy, you can use high purity isopropyl alcohol from a drugstor in your line to help dry it. With small tubing like you have, it will be temporary at best without daily applications.

5-10cc's in your line should be plenty.

I was wondering about isopropyl, all alochol will absorb water to some degree? Looking for the least toxic for the fish. I just picked up some denatured, which I also use in furniture refinishing, but I'll try the isopropyl first. Thanks, Rainman.

The air stopped flowing again last night so there is still moisture in the line. It has begun to snow here pretty heavily so I hope I can get the air going again before it accumulates over the thin ice.

Scruffy, what size and kind of pump do you have ?

I'm using a vacuum pump used for suctioning. My dad used it when he came out of the hospital some years ago.(I don't throw out anything that I think I can use) I'm not sure of the make but it puts out some pressure and if hospitals use it it's going to be durable, and it was cheap.

I didn't have the isopropyl so I used the denatured alcohol, about 25cc injected into the air line and reconnected. Turned on the air and began to see some bubbles under the ice.


Waited about 3 minutes and you could hear the air breaking the ice. Ten minutes later the water was rolling as it was before ice covered the pond. The air pressure went from 38 psi to 20 psi so I know the line was cleared.

Hope it stays this way the rest of the winter, but we have some more cold weather coming in.

take a pic sometime of the pump if you would as even 20 psi is too high. If it is a 10-15 psi model anything above 1.5 cfm the 1/4 inch line is a "pump killer"

Ted,
Thanks for the advice, I'll put a relief valve on the line tomorrow and see how low I can get the pressure and still get sufficent bubbling to keep the ice open.
The compressor dosen't have any labels on it, that I recall, and is pretty small in size. It just fits into the well house along with my small well pump.

I really appreciate all the feed back from you folks. This is a great site and has helped me many times with my questions.

Generally the smaller diameter the airline the quicker it can freeze closed with ice blockage. Thus 1/4" ID like Ted said is a pump killer. As mentioned 1/2" poly irragation pipe (5/8"ID) will take a lot longer to freeze closed. I too would like to see a pic of the pump so we know what type of compressor you have.

I'll post a picture tomorrow. I used a old 1/4" polyester airline I had kicking around that had been broken and repaired a couple of times.

Possibly the splices are where most of your troubles are originating. Although just the 1/4" ID alone is a big cause of concern.

Woke up this morning to a wintery blast of ice cold air and snow. Wind is blowing at 20 up to 40 mph. With the wind chill it is well below zero. Happy to say the pond stayed open all night.


The pump is a Schuco, but that's all the information that's on the pump. I added an intake filter jar after the freeze up to help keep the line clear of dirt. It only had a small paper inlet filter before. The thing in the plastic bag is the water pump timer that I use in the spring and summer to spray water on the pond for aeration.

Here are the photos of the setup and well house.




It's to brutel out to add the release valve today, so it will have to wait.

Okay - it is a small piston pump. You are not getting much air from it. My guess is 0.7-1 cfm at best and possibly 1/8 hp. Benefit to the piston style is higher pressure, thus your 30psi readings. More air volume (CFM) will result in more water movement and a larger opening in the ice. The pump will take a long time to create a turnover in the pond depending on several factors. Others on the forum may be able to locate more specifications for the pump. Next summer try to replace the airline with 1/2" black polyethylene irrigation pipe -abt $10/100ft - low cost; Lowe's, Home Depot.

Bill, Thanks for the feed back.

The compressor is indeed a piston pump @ 1/10 hp. I researched this after posting. At this point I'm only concerned about keeping the ice open and not water turn over. I'll assume the releive valve will bring back the fine bubble pattern I had when the pond had less water in it.