Probably going to be a tough situation regardless. Not sure if you have money saved up but the best thing to do in my opinion would be buy some sort of large temporary pool and set it up in your backyard or garage depending on the temps in whichever state you live in hook up a powerful return pump and have it it pump water directly from the pool to a trash can filled with bio media and maybe some filter floss, this would most likely be the cheapest option. You will probably get stuck doing large water changes weekly until you can have a pond dug but atleast with koi doing colder water changes isn’t a big deal. Most home water heaters in my experience can only handle up to about 150 gallons of 80 degree water before it goes cold unless you have some crazy huge setup going on. Not trying to be a downer but I’ve realized through the years with projects like these something always goes wrong and nothing ever goes perfectly. I wish you the best of luck
This would be the best option BUT I could see this becoming a problem quickly. While the new owners might be okay with him stopping over to feed the fish and do maintenance for a month or so if the pond digging process ended up taking longer then expected or delayed the new owners might sour on this agreement quickly and basically tell him to take his fish and well… F off ( when I moved into my current house the old owner stopped over well over 6 times to “grab” things he left behind in the attic until one day I found out he came over to my house when I wasn’t home and apparently tried to jimmy his way threw a locked door with a screw driver. Let’s just say I wasn’t happy I basically took everything else in the house I thought he had left and dumped it in my truck bed and took it to his new house and told him their was absolutely nothing left of his at the house I ended up just chalked it up to the guy being a weirdo but I was honestly not happy at all about it and almost had to call the cops) this is why I say this agreement with the koi could end badlyCould you make an agreement with whoever is taking over that property to come over and maintain the pond so they have a place to be while you build the new pond?
That's a good point. A written agreement might make it more proper/legal that would protect themThis would be the best option BUT I could see this becoming a problem quickly. While the new owners might be okay with him stopping over to feed the fish and do maintenance for a month or so if the pond digging process ended up taking longer then expected or delayed the new owners might sour on this agreement quickly and basically tell him to take his fish and well… F off ( when I moved into my current house the old owner stopped over well over 6 times to “grab” things he left behind in the attic until one day I found out he came over to my house when I wasn’t home and apparently tried to jimmy his way threw a locked door with a screw driver. Let’s just say I wasn’t happy I basically took everything else in the house I thought he had left and dumped it in my truck bed and took it to his new house and told him their was absolutely nothing left of his at the house I ended up just chalked it up to the guy being a weirdo but I was honestly not happy at all about it and almost had to call the cops) this is why I say this agreement with the koi could end badly