When humans are subjected to stress our immune system is compromised, we become susceptible to pathogens present in the air resulting in colds, flu or worse. Koi are affected by stress also; chasing & netting them, loading them into a plastic bag and transporting them in the trunk of your car is stressful.

These nasties are in the water but don’t affect them when they’re healthy, when they become infected they risk infecting others they are around. To ensure your new fish don’t infect the rest of your fish they should be quarantined for several weeks to several months. Keep a few Koi [inexpensive feeder fish will do] in a quarantine tank to keep the filter activated in case it’s needed as a hospital tank. Before introducing them to your pond, just to be on the safe side, choose a kamikazi Koi to pal around with your new fish for a couple more weeks; if both are OK then you can put them both in the pond.

The reason for the redundancy is that if your fish contract this Koi Herpes Virus you will have to go through hell and back to sterilize and prepare your pond to support fish again. It would almost be easier to dig a new pond! If you don’t think I’m serious go to the following article and read the suggestions of the Fish & Game Commission »

Salt is, also, helpful and one of the best products to use against about 80% of the nasties that might attack your stressed fish. In your tank you can add 1 lb/100 gal/day for 3 days to get a .3% solution which is recommended.

Let the bag o’fish float in the quarantine tank to acclimate the fish and allow the temperature in the bag to gradually equal that in the tank for about an hour. Dump as much of the bag water as possible outside the tank. A strong salt dip is recommended; use approximately 3/4 cup/gal for 7-8 minutes. Watch them carefully as it is very strong and they may try to jump out. They may also start to go belly up in which case remove them immediately to the quarantine tank and hold them upright over the airstone. They will revive. This can be repeated every 12 hours; 3 times total.

What you need is a tank, 100-200 gal should be fine, an aquarium heater to keep the water temperature elevated to around 72-84º [some problems can be solved with heat therapy], a small pump, a filter [you can make one out of a 5 gal paint bucket filled with Springflo, filter mat, etc], and something to cover it so they don’t jump which new fish tend to do.

The bad news is that there is a gill disease epidemic that has no cure as yet and HAS wiped out ponds in a matter of weeks.

One of the best weapons you can add to your arsenal is Doctor Erik Johnson’s book, Koi Health & Disease [the Koi keeper’s Bible] which costs less than the cost to replace your fish!