DIY Series: De-icer

Why do you need a De-Icer ? In Northern Climates (Zone 1 through 5), our ponds can be covered with ice from December to mid-march. This ice can be as thick as 8 inches. The ice traps toxic gases and doesnt allow the exchange of oxygen to occur. If a hole is not left open in the ice, your fish could suffocate and die. Leaving a hole open is no gaurentee of survival but every little bit helps!

How does the De-Icer work ? The Deicer uses the heat from two standard 25 watt light bulbs to warm the air inside the unit. The warm air keeps a hole open in the ice. The black color absorbs sunlight during the day, thus an additional thermal gain. Air takes less BTU to heat than water, so the unit is more efficient than a stock tank heater (which typically draws between 1000 and 1500 watts). This effeciency can add up to signficant savings over the winter months. Here's the cost comparison: Bickal Deicer 50 watts x 24 hours a day x 30 days 1000kwh * .0962 (cost per kwh) = $3.46 Stock tank heater 1000 watts $69.26 So you can see thats a savings of $65.80. Thats enough to pay for the unit in its first month. In central Iowa, we usually have 3 months of ice on our ponds. Try the cacluation yourself using my on-line calculator

I started out my first year ponding like most everyone else. The warm summer flew by in an instant and winter was upon me before I knew it. As the first ice crystals formed on my pond, I began to worry about my precious fish below the ice. There wasen't alot of information about overwintering ponds back in those days (mid 1990's), I heard the same methodical sound byte from everyone "lower your lily plants and keep a hole in the ice for the bad gas to escape." So I set off to do just that. My first attempt, was the more popular "put your pump just below the pond surface". As you will see in the picture that kept a hole open (for a few days). Eventually the water kept freezing around the lip of the hole until the entire surface was one big bubble that looked like a coffee pot percolating below. The next idea that I heard from everyone was to use a cattle tank heater. They came in 1000 or 1500 watts and only cost like $60 a month to run. Well being the cheapskate that I am, I wasn't about to spend that kind of money. My next attempt was something that I heard about at a pond club meeting. It was about a device made from an inflated car innertube that floated on the water. Attached to the top of the innertube was a piece of plywood. Hanging inside this floating contrapion was a lightbulb. The concept was, that the light bulb would heat the air and that would keep a hole open in the ice. Being the skeptic that I am, I was in disbelief that a light bulb would keep a hole in ice that can get up to 8" thick, I just had to try this out. That night I set up a plant container with a lightbulb inside. I uncovered a spot on the ice and set it in place. I let this unit set on the pond for 24 hours. That night it had snowed a few inches. When I went out to check the unit it had snow setting on top. I thought to myself, no way would this thing have melted a hole in the ice, if it wasn't even strong enough to melt the snow from the top of itself. I lifted the unit up, and to my utter disbelief, it had melted a hole in the ice, the entire size of the container. I was amazed. Luckily it had not melted too big of hole, or it would have fallen in the water and could have electrocuted my fish. Since the science was proven correct, I set out to design a unit of my own. I wanted something strong that could survive for years without need of repair. Car innertubes were a difficult item to come by and I worried about possible deflation, so I searched for an alternative. PVC pipe was lightweight and very durable, and held up well under the cold, and was available everywhere, So I built a floating framework out of that. Then I Attached a black cement mixing tub to the top and put two 25 watt lightbulbs inside. I used hot water to open a hole in the ice, big enough to place the unit, and let it sit. On the warmer days, the deicer would blow around a little bit, and the hole would get larger. The colder it got the deicer would get frozen into place. I checked the unit every day, the ice was always melted underneath, and at night you could see a glow from where the unit lit up the ice and snow from underneath. It even looked pretty. Well winter got colder and colder and the unit kept working, even on nights when it got -20 below zero. During the day, the black tub would help absorb heat from the sun making the unit more efficient. Spring finally came and the ice melted from the pond. All of my goldfish had survived the winter and the deicer was a success. I showed my deicer to several people in my pond club, they thought it was a awsome. The follow fall, many people from the Eastern Iowa Pond Society got together and built about 12 of the "Bickal Deicers". I'm pictured in the lower left.

How to build a De-icer Disclaimer There is no guarantee that this deicer will keep your fish alive. Only that it will keep a hole open in the ice. I have learned over many years of raising koi that they do not survive well when water temperatures drop below 40 degrees for extended periods. It is my recommendation that you do not allow koi to go through such harsh conditions. My recommendations for keeping koi, is that they are kept in a water temperature which never drops below 50 degrees Farenheit. This device is not UL listed, and can pose a health risk to your fish. It should be plugged into a GFI Outlet, and properly grounded at all times.

Design Features The unit is designed with 2 bulbs to provide redundancy and will still work if one bulb burns out. Proven effective up to 15 degrees below zero with a 45 below zero wind chill factor at the recommended wattage. Higher wattage bulbs may be used, but are not recommended. The floatation ring is filled with styrafoam to prevent sinking in case the base were to get ruptured. Bulbs may burst if they come in contact with cold water. Deicer should be plugged into a Ground Fault Protection Outlet (GFI). Snow, Debris, and small animals should be removed from the top of the de-icer to pre-vent sinkage. The unit is designed to support its own weight only !!!

Materials Needed Qty Item Size Comments 1 Black Plastic Tub (rectangular) 18" x 24" and 6" deep. Black is used because it obsorbs energy from the sun. A the tub should be deep enought that it will keep the light bulbs a sufficient distance from the waters surface. 1 PVC Pipe 4" Sewer grade, Schedule 20. This pipe is lighter than Schedule 40. Heavier grade pipe may not provide enough bouyancy. 4 PVC Elbow, 90 degree 4" Sewer grade, Schedule 20 1 PVC Glue & Primer 8oz Bottles 2 Light Fixtures Plastic. Preferrably fixtures with grounding capabiltiy. 2 fixtures are used to provide redundancy. Light bulbs will burn out at different rates, having 2 bulbs will allow the unit to operate until a bulb can be replaced. 1 Wood 1x4 stock, 32" long Preferrably moisture resistant lumber 1 Power Cord 3' It is recommended that you use a power cord which will allow your deicer to plug directly into the GFI outlet. For purposes of this installation, we will assume that a separate drop cord will be used, and so the instructions are geared towards the safest installation. 2 Light Bulb 25 Watt This size bulb is sufficient. If you use too high of wattage of bulb you could melt the unit and cause damage. 2 Expanding Spray Foam or Styrofoam Can Optional. As an emergency precaution against water in-filtration. The ring which keeps the deicer boyant is air-tight. If enough water were to enter, it could cause the unit to sink. 1 Roll of Foil Bubble Wrap 6'

Assembly Instructions Measure the distance between the elbows to determine the length to cut the pipe starting with the end. Measure the distance between the elbows to determine the length to cut the pipe for the side of the unit. Mark and cut the PVC pipe for both ends and sides. Once the cuts have been made, lay the pipes out to ensure that the pieces are correctly sized. Note: At this stage you could fill the pipes with expandable spray foam (or) chunks of styrofoam as an emergency precaution against water in-filtration. The ring which keeps the deicer boyant is air-tight. If enough water were to enter, it could cause the unit to sink. Apply PVC primer to both ends of each pipe and allow to dry. Apply PVC primer to both ends of each elbow and allow to dry. Liberally apply PVC glue to one end of an elbow. Liberally apply PVC glue to one end of a pipe. Once the glue is applied push together the elbow and end pipe. Ensure that the pipe is inserted as far as it will go into the elbow, and allow at LEAST 15 seconds drying time. Glue a second elbow on to the opposite end of the pipe. To ensure the elbows line up correctly, place the assembly on the floor as shown, and allow at LEAST 15 seconds drying time. Repeat the process with the 2 other elbows and the same sized pipe. Glue the remaining pipes into the ends of each elbow as shown. Glue the remaining elbow and pipe and finish the pipe so that you have a “rectangular ring”. Measure the inside of the bottom of the tub from to determine the length of the board needed to mount the light fixtures. Mark and cut 2 pieces of the board to the proper length. Both boards should be the same length. Lay a single layer of the foil bubble wrap inside the length of tub. leaving 2” (approximately) of excess. Form the bubblewrap to the inside shape of the tub. Cut the bubblewrap on the opposite end, again leaving 2” (approximately) of excess. Repeat the process across the width of the tub. Lay one of the boards on the ground/floor, place the tub and foil wrap on top of it and center so that the board on the outside of the tub will sit in the middle of the tub. Center the other board on the inside of the tub so that the boards are aligned as closely as possible. Screw the board from inside the tub to the board on the outside of the tub, affixing 2 screws. If necessary, lift the unit off the ground to verify the boards are lined up. If not remove the screws and adjust. Screw in 4 more screws in the positions shown. Place the tub on top of the glued and dried pipe “rectangular ring” and center. Mount the tub to the ring by placing a screw at each corner. Attach the screw through the joint where the pipe and the elbow are glued together. Place another screw on "kitty-corner" to the first. Repeat this process on the other 3 corners. Trim off the excess bubble-wrap. There will be a small gap in each corner of the unit. This is designed to allow for proper gas/oxygen exchange. This gap is also visable from the inside of the unit. Drill a ¼” hole through the top of the unit approximately 2” from the edge of the board. Cut approximately 12" from the bare end of the power cord. Strip away the outer covering exposing the colored wires. Strip away approximately 3/4" from the wires exposing the copper. Attach the Black and White wires to the first light fixture. If your light fixture does not have a ground screw, you can snip off the green wire. Attach the fixture to the opposite end of the unit from where the drill hole is, by screwing into the board. Insert the stripped end of the power cord through the hole so that the black and white wires from both cords may be attached to the other light fixture. Ensure that the green wire is again snipped from both cords. Attach the wires to the second light fixture. Attach the second fixture to the unit by screwing into the board so that they are approximately 8” apart. Turn over and tack the power cord to the top board using a wire clip to ensure that the cord will NOT touch the water at any time. The male end of the power cord should not come any lower than the edge of the tub. This prevents any connection to a drop cord from hanging into the water. Apply silicone sealant LIBERALLY to the hole around the power cord. Liberally apply silicone sealant to each of the areas where the tub is screwed to the ring to prevent the PVC from filling with water. Screw in the 2 light bulbs. Assembly finished.

Other Sizes Check out the mullet! Hey, it was the 90's. Here are the 2 standard sized de-icers that I have assembled for clients: Here is an even larger size de-deicer that I build for my own pond (when I used to raise just goldfish)