Once a fish becomes ill it is imperative to have a place to treat it without infecting the entire pond! And once a hobbyist has established a relationship with his/her fish, it will be more meaningful when someone tells them that one infected newcomer can kill every fish in the pond. Even worse, once that happens, we become believers! This is usually the point at which we all become REAL koi owners. We begin to seriously take responsibility for our charges out there in the pond and are now open to whatever is going to safeguard their welfare. The fish have by this time become members of the family.

I was able to purchase a large white circular-shaped polyvinyl tank, 5’ across and 3’ deep. Originally it was 5’ deep but couldn’t be delivered until we shaved off two feet. Initially I thought it might be going into my basement, but even at this size it wasn’t going to happen. So, I decided to bury it in the yard, near the house for convenience. That was when we uncovered the old (formerly used but now forgotten) heating oil tank. Rather than try to exhume the tank, we opted to bury the new quarantine facility half-way down. Leveled off and finished, it was 18” below the ground and 18” above. I found it to hold approximately 460 gallons when filled.

The next issue was filtration. I had a submersible pump, hoses, clamps and strainers to keep it from pureeing fish. On the other end I had a large rectangular box type filter connected with an overflow to return to the pond. This worked for several years until the hose separated from the pump.

I don’t like submersible pumps in ponds, but don’t mind putting them in the filter units, so it was decided to install two bulkheads through the polyvinyl tank, one for a new retrofit bottom drain and the other for the return. The box filter is leveled beside the tank with filter pads and springflo inside, and the pump is now housed in the back of the filter unit. Now, instead of the filter grinding up larger debris and pushing it into the filter it is pulling it in through the filtration materials and pushing clean water back to the tank. The next step is to separate the filtration media into cubicles. This box filter will become an up-flow and down-flow media box for super-clean water. There is a knife valve on the end for easy cleaning, with an attached hose to a designated spot away from the house. When the partitions are installed I may need to add more valves to purge dirty water.

My tank is efficient. It is close to the water and electric sources. It is sheltered and out of the wind and weather by being close to the house, so the temperatures remain more constant. I have the light from the house and porch in case I need to check them during the night. And I can keep watch on the fish from indoors.

I would just add one more thing, maybe two- koi don’t do well in solitary confinement. They need companion fish in order to heal. So I keep one goldfish in my quarantine tank for such purposes. That fish goes through all the treatments with the koi and comes through with shining colors. The second thing is the net over the tank. Whenever a fish is put in a strange place they try to escape! It’s just their nature. And when they jump they usually kill themselves unless you have a net to keep them in there. So, if you still think a quarantine tank is a luxury, I guess your fish aren’t a part of the family yet. And if you think you can’t afford a quarantine tank, mine cost me all of about $325 without the water. Compared to the prices of some koi, what are we talking about?