How to take care of a lot of fish from a leaky pond.

The biggest problem we had when rebuilding the pond is what to do with our fish. We had five adult koi from 18” to 24” long and six juveniles of varying size. We were exploring different options, including stock tanks and show tanks, but that got expensive quick. It would also have been challenging to set up filtration on the number of tanks we’d need.

In early 2017, when we were approaching the planned start date, I brought up our problem with the first pond builder. He suggested buying an above ground swimming pool- one without an algaecide added during manufacturing. This was a great idea and probably saved our fish. The brand the builder recommended was Intex because they did not use algaecide in their pool material. After some internet searching I was able to find a previous year’s model pool for $299 on Amazon. After calling Intex to make sure the pool was algaecide free, I placed an order and it was on our doorstep 3 days later.

The pool we picked was 15 feet in diameter and 4 feet tall. Based on a water level of around 3 feet 8 inches and pool diameter of 15 feet, the total volume of water for this pool is around 5000 gallons. This is plenty of water for the number of fish we have, and I quickly realized I could use the Ultima II 20000 filter on the pool if I had a pump. On a club member’s recommendation, I sized and bought a Performance Pro Artesian 2 5800GPH pump, which I immediately put to use on the Ultima II filter. We plan to use this pump on the new pond.

In April 2017, I began the pool setup. To even out the ground, I layered sand over the gravel underneath the pool in our backyard (we plan to regrade and replace the driveway). I assembled the pool and plumbed in the pump and filter. I ran the 3” pump intake across the bottom of the pool and put a tee on the end with two drain grates on either side. The intake plumbing runs up over the edge and down to the pump, through the filter, and back into the pond. Outflow from the pump is enough oxygenation. We used ammonia salt to kick start the filter. I added a layer of rigid foam insulation around the pool and filter and built a box for the pump. Then, with the help of club members, we transferred the fish from the pond to the pool in May 2017, anticipating the beginning of the construction project.

The temporary pump house. This was build using 2x2s and cheapest 1/2 plywood I could find.

The pump and plumbing form the pool into the filter. The electrical wire in the top fo thge pump house is a pipe heating wire to ensure nothing froze up over the winter.

This is the Ultima 2 filter with 2 layers of thermal barrier wrapped around it. The opening around the pressure gauge was added this spring.

Nearly a year later the fish are still in the pool. We have had to make some modifications over the course of the summer and this winter, but the fish have made it through mostly unscathed. Keeping fish in an above ground pool has been somewhat challenging, mostly due to wide temperature fluctuations over the seasons and even over the course of a day. That being said, I am not sure we would have any fish left if we have bought a bunch of smaller tanks and tried to keep them in tanks for a year. We are really looking forward to having the new pond finished.