I have started a new project. I have decided to build an above ground, "portable", rectangular fish pond from landscaping timers, rebar, and pond liner. The pond measures, roughly, 2'x4'x8' and will hold about 400 gallons. In my case it held 440 gallons, but I dug 4" to 6" of the bottom into the ground.
The empty weight is probably no more than 400 pounds, so it can be moved faily easily by propping it onto a couple of furniture dollies and rolling it to its new location. This is very convienient if you have a need to transport it into a protected storage facility in the winter, such as a garage or greenhouse. I intend to use my pond to raise and breed tropical fish and hold pond plants during the Spring, Summer and Autumn months. It could also be used to hold a small number of koi year round.
The design is extremely simple and can be assembled by one individual over a single weekend. As an added benefit, it is low cost. It is not, however, a fancy in ground oasis where families can gather about on the patio and sing. I don't really sing much anyway.
The supplies you will need are:
24 3"x5"x8' landscaping timbers ($1.97 each = $50)
12 1/2"x2' rebar ($.88 each = $12)
2'x32' cardboard
3 1/2"x4'x8' sheets of insulation board ($8 each = $24)
undelayment pad ($10)
10'x15' pond liner ($60 + $20 shipping)
3 2"x8"x10' pressure treated wood ($9.95 each = $30)
14 3-1/2" deck screws ($2)
1/2"x4"x8' wood plank ($3)
4 nails
duct tape
water sealer
5 bags of play sand
old newspapers
Building supplies can be found at your local hardware store. Pond supplies can be ordered online.
The total cost is then about $225 including tax.
The following tools will be needed:
circular saw
drill
digging tools (shovel, pick ax, etc.)
level
handheld sledgehammer
staple gun with staples
tape measure
utility knife
pencil
paint brush
3/4" wood boring drill bit
water hose
Description: The landscaping timbers are laid out in a rectangular log cabin fashion and levelled. Each timber has 3 holes drilled where the rebar is inserted. The cardboard is attached to the inside walls of the pond, sealed with duct tape, and followed by the insulation. The sand, newspaper, and undelayment are laid on the ground. The pond liner is then added and filled with water. The pressure treated wood planks are cut into a frame and attached to the top. That's it. Simple.
The above design can be easily modified to meet your own personal needs. For instance, you can choose other shapes like hexagons and octogons, maybe even tarragons or klingons. You can also replace the wood with 4"x4"x8' cedar fence posts, or 6"x6"x8' treated beams.
Step 1:
Cut 8 of the landscaping timbers in half. You should now have 16 4' and 16 8' timbers. Each side will be 8 timbers high.
Step 2:
Make a template for marking drill holes. When you purchase the 1/2"x4"x8' wood plank, make sure the plank is flat and not warped or bent. You will need to measure out 4 points eactly in the middle of the plank. Measuring from one end, mark points at 2-3/16", 6-9/16", 45-13/16", 93-13/16". Hammer a nail into each point marked so that it just barely protrudes through the wood. Be sure to pound the hammer as vertically as possible. You can verify this by measuring the protruding points to ensure they match the measurements provided. The first two points will be used to mark both the 4' and 8' landscaping timbers. The third measurement is used only for the 4' timber. The last measurement is use only for the 8' timber. Each timber will have three holes drilled.
Step 3:
Lay the template onto two of the 8' landscaping timbers so that it lines up with both ends and is centered. Tap each of the three end nails to mark your holes positions. Remove the template and verify the the marks are clear and centered. Using the drill and 3/4" wood boring bit, drill holes 3/4 of the way through the timber - resist the temptation to drill completely through. I do not recommend a smaller drill bit, such as a 5/8", unless you are absolutely sure all the holes you drill will be perfectly placed taking into account small differences in the lengths of the timbers.
Step 4:
Repeat step 3 for two of the 4' landscaping timbers.
Step 5:
Choose a good location for your pond. Ideally you want an area that is fairly level and at least 4'x8', but should be large enough that you have walking access to all sides of the pond. I left a minimum of 5' on all sides - an area of 14'x18'. You will want an area that gets some full sun for the plants to thrive.
Step 6:
Lay the 4 drilled timbers on ground and level them. This may require digging trenches as I did unless, of course, your ground is already level. You will want to make sure the timbers are squared up (or rectangled up in this case). I used a square to get them in position, but that isn't necessary. Just make sure when you are done that the cross measurement from corner to corner is about 112". You can use that sledgehammer to tap them into position.
Step 7:
Insert the 12 pieces of rebar into their respective holes. Make sure that the rebar you purchase is not bent (even slightly) or fitting the pond together will prove more difficult and may require an adjustment to the drill hole locations.
Step 8:
Repeat steps 3 and 4 for all the remaining timbers. For these timbers, you will be drilling the holes complete through. After drilling each timber, turn the timber over and remove the wood flashing that remains. If you would rather, these can be drilled as you go. I did.
Step 9:
Assemble the rest of the timbers. The sledgehammer comes in handy for those tight fits.
|
Step 10:
Take the sledgehammer and pound the ends of the rebar so they are flush with the top of the landscaping timbers. In most cases, this will not actually go completely through the bottom timber. Recheck your levelling. If your pond is no longer level, disassemble and start over - or live with it.
Step 11:
Once the frame is complete, the ground within the pond should be smoothed by removing excess rocks and sticks. It is a good idea to dig out a small portion of the base to be lower than the rest. The purpose of this is so that if a leak occurs on the bottom of the pond, there will likely be a small pool where your fish can congregate until you have the opportunity to save them. The deepest area will also collect most of the pond muck, making cleaning easier. You may decide to dig out the pond deeper. The deeper the hole, the more stable its water temperature will be. This will, of course, reduce the portability of the pond. If you plan on ever moving the pond, for instance, relocating it into a garage during the winter months, then you probably do not want the pond much deeper than the base of the frame. We will also be adding an insulation layer next, so the depth of the pond into the ground should be less important than for most above ground ponds.
Step 12:
We chose to stain our pond at this point. You should stain the pond before there is water in it so that the noxious fumes do not cause a die off. We are doing this early to leave plenty of time for the fumes to disipate. I used some old fence stain/sealer I had sitting around. The frame (will until stain dries) should then be sealed with a water sealer such as Thompson's. This is very important, because pressure treated wood contains both arsenic and copper which can build up in your pond from runoff, and kill your fish and the beneficial bacteria in your filter. Alternative woods may be used such as redwood, cedar, or cypress. Note that water sealer usually suggest waiting until there is no rain in the forcast, and that the temperature is greater than 40 degrees F.
Step 13:
Cut the 3 2"x8"x10' pressure treated boards into a frame at this point since there is time while waiting for the noxious fumes to disipate. After the boards are cut, the cut ends will need to be stained. The frame should be cut so that it lies centered on the top of the pond. The long sides should measure 102.5" and 52.5" and the angle should be 45 degrees. To make this easier, I cut the 1"x4"x8" template board in half and put each piece in my miter box and cut them at 45 degrees. I then placed both boards together on my frame pieces, and marked the line to be cut.
Step 14:
To protect the bottom of the pond liner from remaining rocks and roots, we will first lay down old newspapers, followed by the underlayment pad. The underlayment should be placed on the bottom and then stapled to the inside frame being sure not to pull it too tightly. We are only putting a total of 8 staples to keep it from falling back down into the bottom. Do not trim the underlayment to fit. We want it feeding back up the sides so that when the cardboard is added, the cardboard does not come in direct contact with the ground. A small layer of sand (1" to 2") could first be laid down, however I could not readily find any "play" sand. Do not use paver sand as it can have rough pieces which defeat the purpose. Play sand is sometimes sold by grocery stores. Check those in your area.
Step 15:
Before the pond liner is added, we must protect it from the rough inner surfaces of the landscaping timbers. We also want to create a smooth inner surface. To do this, you will take 2' strips of cardboard and staple them along the top only. Use duct tape to seal the seems. If your cardboard is being reused from old boxes, make sure there are no stapes or nails left behind.
Step 16:
To reduce the thermal fluctuations of the pond, by reducing heat loss through the surface area of the exterior walls, we will insulate the pond. Will will use 2 layers of 1/2" R3 styrofoam insulation. Together they will achieve an insulation rating of R5. Cut the insulation boards to fit the inner diameter of the pond and so they fit snuggly. The inner layer will need to be attached to the sides. I used 3 headless 2" paneling nails and put them as high as possible. It is not necessary to attach the inner layer to the cardboard as the weight of the water will keep it in place. The inner layer should also sit slightly lower into the bottom overlapping the bottom seem somewhat.
Step 17:
The pond is now ready to add the liner. I purchased a 10'x15' EDPM 45 mil pond liner from watergardenponds.com for $60 plus $21 shipping on a Sunday evening. I paid for 2-3 shipping and UPS delivered it Wednesday at 4 P.M.. I would have preferred a Permalon HDPE 20 mil liner, but it would have actually cost more due to the available size limitations. The disadvantage of the 20 mil liner is that it is thinner, and therefore is easier to puncture. The advantage is that it is thinner, lighter and easier to work with - especially when folding corner seems. In the end, the corner seems were not that difficult to master as you can see from the photos. Take the liner and lay it out on your lawn being sure to not puncture it. If this is a roofing liner (instead of a pond liner), it will need to be washed to remove talc, and cleaned with a vinegar/water solution to remove the chemicals it is treated with. If it is a pond liner, as mine was, it should be rinsed with a water hose only to remove any surface impurities. After cleaning, stretch the liner over the top of the pond keeping any imprinted lettering on the bottomside so that it now visible when installed. Now lower the liner into the pond making the bottom as flat as possible.
Step 18:
Begin filling the pond using the water hose. Note the reading on your water meter when you start and when you stop to get an accurate volume measurement in gallons. While the pond is filling, adjust the corner seems to make them as flat and non-obtrusive as possible. Try not to leave hidden pockets where fish can get trapped and die. While it is filling you probably need to stand inside the pond and continually adjust the liner so that as few creases as possible occur. You are almost done now, so enjoy yourself and get wet.
Step 19:
Once the pond is full, the frame should then be attached to the top of the pond using the 3-1/2" deck screws. Make sure that the sealed frame pieces have dried thouroughly.
Step 20:
Using a utility knife trim off the excess pond liner.
Your pond is now complete !!!
Other Considerations:
You will immediately need to add oxygenation and filtering to your pond to keep the water clear, healthy, and free of algae. This can be accomplished with plants alone if the fish load will be small. More than likely you will want to buy a pump and filter. I purchased a Pondmaster 1500 kit from petsolutions.com for $95 plus $11 shipping. The kit includes a 12"x12" filter with bio and carbon pads, a 500 GPH pump, and two fountian attachments. When choosing a pump, it should, at a minimum, turn over the volume of the pond once every two hours. It is recommended that the volume is turned over every hour. I purchased a pump that will turn over slightly more per hour than the volume of the pond. If you find the pump you purchased is too powerful, a ball valve can be added to the pump's output to reduce its flow and thereby increase the pump life. If you plan on adding a waterfall feature to your pond, you will more than likely need a pump more powerful than that recommended. As a bonus, the kit includes a fountain attachment that can be setup immediately to begin oxygenating the water. If you intend to keep goldfish or koi in your pond, you will need a far more powerful filter system than the one I purchased.
Update: The filter I purchased did not work well at all and eventually was just worthless. I purchased the Tetra Pond ClearChoice Submersible Filter and it cleared up the pond in just a few days. The filter is small, submersible and can be connected to many of the existing pump assemblies. The hose did not fit mine perfectly, but I was able to jam them together well enough that I can move them around in the pond without them coming undone - good enough. I am very happy with it. I found it at an e-bay store for $37 door-to-door.
Before connecting up your new pond pump, you will need to get electricity to your pond. There are a myriad of ways this can be accomplished, however two important considerations should be that the electrical connection is at least 4 feet away from the pond so that moisture will not come in contact with the outlet, and a ground fault interupter (GFI) must be used for the electrical circuit. This will protect you from electrocution if the pump were to fail and short.
You may also wish to add a submersible light to your pond, so that you can view your habitat at night. The fish won't mind, and it may get you singing. Submersible pond lights can be ordered online from either of the websites previously mentioned.
Update: The light I purchased was also worthless. I do not recommend any of the cheap lighting available.
Mosquitos are always a major concern for pond owners. Make sure that you keep plenty of mosquito larvae eating fish in your pond. Many pond owners keep Gambusia sp., which tend to be very prolific and can be purchased at your local pond supplier or obtained free from other pond owners in your area. They will eat the larvae, but will not have any effect on the attraction a large pond of water has to the mother mosquitos, which are the ones that bite. Unfortunately I can't help you there.
Another consideration is pond heating during both the Summer and Winter months. In the Summer, you are of course trying to avoid it. On those few days of the year when the temperatures are the hottest, and your pond is overheating causing your fish and plants to suffer, I recommend picking up a bag of ice on the way home from work, or better yet at lunch time, and dumping the ice into the pond. A $2 bag of ice 20 days during the year is only $40. You can also freeze gallon jugs of water in your freezer if you have room, and simply float these. If you choose this route, do not overfill the containers as the water will expand when it thaws; remove all labels and glue from the outside of the container; and find a way to anchor the bottles in the pond so that fish are not trapped between the heavy container and the side of the pond - killing them.
If you choose to leave your fish in the pond during the Winter months, you may want to heat your pond. I keep tropical livebearing fish who can easily sustain water temperatures ranging between 65 and 85 degrees F. If you keep koi, goldfish, or natives, they can survive comfortably at even lower temperatures. Water evaporation can account for as much as 80% of the total heat lost from the pond, so the first thing you should do when the temperature begins falling is to cover your pond. One of the easiest ways to cover a pond is with plastic sheeting and tacks. You may also want to float styrofoam sheets on the water's surface and shutdown your pump. On warm days, the pond should be uncovered and the pump turned back on. For a typical inground pond, the ammount of heat (in BTU/hr) needed to warm a pond to a desired temperature is equal to the difference between the average outside temperature (in degrees F) during a 24 hour period times the surface area of the pond (in square feet) times the rate of heat transfer over that surface area which is equivalent to a multiplication factor of 15. If the pond is covered, this heat loss factor is only 3. Since this is an above ground pond with thermal insulation permenantly installed on the sides, the entire surface area of the side walls must be considered as well. The entire surface area of this pond is then 80 square ft. As an example, if the outside temperature is 40 degrees F and we wish to heat the pond to 70 degrees F, the ammount of heat needed is 80 x 30 x 3 = 7200 BTU/hr. This is equivalent to 2.11 kwh/hr or 50.6 kwh/day. If you are paying a typical $.08/kwh through your electrical company, this would cost you roughly $4/day for heating or $120/month - ouch! An inground pond would have only cost 40% of this. A 1000 watt submersible heater running fulltime produces only 24 kwh/day, so you would need at a minimum 2 heaters, but more likely 3 if you needed to handle lower temperatures into the 30s. 3 heaters would run you $500 or more. You could use a single heater if your intent was only to extend your pond season for a month or so. Food for thought.
I have golden retrievers. After I setup my last pond several years ago, one of my dogs came into the house and dropped a fish at my feet. The fish lived for several more years, 3 others disappeared. Predators can come from anywhere - dogs, birds, snakes, cats, etc. There is no way to protect against all forms, but one easy thing you can do is to purchase a floating pond net and cut it to fit your pond (you may need a cut out for your water features and plants). The net can be attached to the back side so that when you are viewing the pond, you need only flip it off out of sight. You can also install hooks on the front side of your pond so that it remains in place. In fact it does not even need to touch the water at all. Most nets have a 1/2" nap. An added benefit of these nets is that they keep debris out of the pond as well - very handy in autumn.
Update: I found the net to be cumbersome, tore easily, and did not keep out the leaves as I expected. When I added tall plants it became unusable. I put it away keeping it only for emergencies - Autumn.
A pond is just an overlarge aquarium, and as such, its water chemistry should be checked periodically, and water changes should be performed if the nitrate levels rise above 50 ppm. In the interim, water can be added directly from the hose to top off water loss due to evaporation. A dechorinator should be used anytime more than 20% of the pond volume is added.
We have had so much rain the past Spring and Summer that my swimming pool (no fish) has overflowed at least a dozen times. You may need to periodically remove water from your pond if you feel the next rain may cause it to overflow. You do not want any of your little fishes washing over the edge. The depth of your pond is less important than the surface area. You can lower your pond level as far needed at anytime as long as the pump remains submerged.
|
