My Pond Journey: Part One (building the pond)...
I had wanted to build a pond for a LONG time and I finally got the chance to do so last summer (pond was built in 2016, original post was in 2017 on my goldfish forum). My original idea was to have a partially in ground but mostly above ground pond that wrapped around two sides of my existing concrete patio in a L shape. The more I looked into this concept and how much material it would take to build it seemed very complex and VERY expensive (over $1000 in materials alone). In the end, I decided to stick to a standard rectangular shaped pond and got down to planning and picking materials. I was trying to pick a material that was readily available and relatively inexpensive which led me to narrow it down between 4 x 4 landscape timbers or the standard rounded off landscape timbers. Again, $$ was a big deciding factor and I went with the standard rounded off timbers because it was about 1/2 the cost (under $400 for the rounded off landscape timbers compared to almost $800 for the 4 x 4 squared timbers). (1st picture)
The final plan was to buy 8 foot long landscape timbers and cut enough of them in half so that I would have a pond that would be 4 ft by 8 ft for the outer dimensions. I still wanted to dig down into the ground a little but ended up putting it all above ground in the event that I decided to sell the house and the potential buyers did not want a pond. I don't know who wouldn't want a goldfish pond in their backyard, but I can imagine some people wouldn't? You know, those people that don't like fun things.
I decided that I was going to line the inside of the framework of landscape timbers with plywood to provide a more solid/even structure to put the liner into and started to build. The base of the pond was a 4 x 8 sheet of 1/2 inch (or 3/4 inch?) plywood supported and/or leveled out in some of the corners by 12 x 12 concrete pavers (2nd picture). I started laying out the timbers on top of the plywood in an overlapping "log cabin" fashion and I would pre-drill and hammer each new layer into the previous one using 6 inch long galvanized steel nails. (3rd picture) This went on for what seemed like an eternity over the span of a couple days before I finally felt like I had it tall enough or got tired of the process.. (I ended up stopping at about 30 inches high to allow tiny humans to be able to see into the pond without a step ladder). Once I had the main part of the pond as high as I wanted it I lined it with plywood and cut off the extra plywood that was sticking out above the timbers (4th picture).
Once the box was lined with plywood I placed the pond liner inside the box and folded it to fit the shape of the rectangle which is a lot more difficult than it sounds. After putting the pond liner in the main part of the pond I started building he overflow box and topped off the rest of the pond edge with some 1 x 6 boards to give it a more finished look (Picture 5). I finished building the overflow box as high as I wanted it to go and lined it with plywood as well. After the overflow box was lined with plywood I cut off the excess liner from the main part of the pond to see how it would look (Picture 6). Then came the really hard part.. I lined the overflow box with pond liner and started trying to figure out the waterfall feature itself. As you can see in Picture 7, I initially had a really large opening that was lined in pond liner which led to water just running over the edge and dripping down the front of the wood into the pond below. After a lot of reading and researching on the internet I decided that the opening was too large and the material was allowing too much leakage around the sides. That's when I decided to make the opening smaller and to build a spout out of metal instead of plywood lined with pond liner. (I still don't know what I was thinking with that first idea, I probably just wanted to get it built and be done with it..?) The first spout was made of sheet metal which of course rusted/corroded overnight and was quickly replaced with aluminum (Picture 8 shows the original sheet metal spout). With the aluminum waterspout in place I was finally done with the overflow box, right?
Wrong... I still had some leakage issues but I did some more reading/researching and ended up talking to my uncle (who has ponds of his own) and he suggested I spray the area where the metal spout meets the pond liner with the rubberized "leak seal" spray and allow it to dry for at least 24 hours before turning the water back on. I followed his advice and found the spray he suggested (triple checking to make sure it was safe to use around water and fish) and after using it I allowed it to dry/cure for 24 hours. Finally, the leaking was gone for good and I was ready to put the 1 x 6 boards on top of the overflow box to finish it off (Picture 9).
Based on comments and questions from the original post on my goldfish forum, I will add the following details below...
I used the Total Pond liner from Home Depot and it's 14.5 mil PVC with polyster weave in between the layers, which according to the website that makes it equivalent to 20 mil PVC in strength. I bought one of the larger liners they had because I didn't know how big the pond would end up being (originally planned it to be about two times larger than it ended up being) and I believe I got it for around $100 or so at the time. I measured the inner dimensions of the pond the other day and I came up with about 450 gallons when I have it about 1 1/2 to 2 inches from the top of the liner plus another 20 gallons in the overflow box. SO total volume of water circulating through the system is about 470 gallons @ 1000 gallons per hour (give or take due to gravity in tubing, etc).
I live in north Texas where it rarely gets super cold, for example we had one or two days where it got at or below freezing this "winter" and the top of the pond tried to freeze over. We occasionally will have a stretch of 2 to 3 days where it will get cold enough to get icy on the roads/bridges but it hasn't gotten super cold the last couple of years. It does get rather warm here during the summer but the fish seemed to do pretty well last summer so I am hoping this year will be the same. I wanted to dig down at least a foot or two to provide some sort of protection against freezing in the cold months and getting too hot in the summer, but it would have required more time and more money on renting digging/trenching equipment, etc. I hopefully won't regret not doing so in the future but so far it doesn't seem to be a factor.