Combining two established koi ponds.

[Justin_Dizon]

I have two koi ponds that are approximately 500 gallons each. They were conjoined at one point but a leak caused me to split up the two liners putting half the fish into two separate halves. I have since then resealed the two liners after a few months and am getting ready to combine the two again. My main concern is the different bacteria in each pond killing the fish when the two ponds are joined. I was advised at petco to swap the filter media of both ponds with each other to acclimate the koi to the other bacteria. I’m not sure if this method would work and would want to know the safest way to combine the two ponds without harming the fish.

 

[Lisak1]

What? I've never heard of ANYONE being concerned about different bacteria in two different ponds, especially two ponds that are a few feet apart. Beneficial bacteria will never harm fish. If there were bacteria in Pond A that was harmful, then the fish in Pond A would be affected - fish don't get "used to" bad bacteria so acclimating them to the bacteria from the other pond is a pretty useless idea in my mind. I honestly don't think you have a single thing to worry about in that regard. When you introduce new fish to a pond the concern is that they are introducing parasites to the pond - or vice versa, that your existing fish are harboring parasites that will sicken the new fish. But with two existing ponds full of (I assume) healthy fish, that would not be a concern either. I would guess whatever is in one pond is in the other and everyone is doing just fine.

When you talk to people at PetCo you're generally talking to someone who has pretty close to zero knowledge about ponds... and many times they don't know a whole heck of a lot about aquariums or fish, either!

Welcome to the GPF by the way! Very pretty pond(s)!

 

[Tula]

I'm wondering if you're referring to bacteria and parasites that are always existent in our ponds, that healthy koi have the ability to resist.....and your concern is the koi in one pond may not have been exposed to the same pathogens in the other pond? I think this is the reasoning behind QT of new fish.

 

[mrsclem]

This is something I deal with. I have 2 koi ponds. Both different setups. I keep everything seperate, no moving fish from one pond to the other. Don't worry about nets or moving plants but I will admit, I am hesitant to move a fish from one pond to the other.