Need Advice on Temporarily Rehoming Goldfish (Pond Setup & Water Quality Concerns)

[Landman]

Hey everyone,


I’ve tried reading through a few threads on here, but I’m still not totally sure what’s best for my situation, so I figured I’d ask directly.


I could really use some advice on taking in some extra goldfish temporarily. My friend is moving and needs me to care for his fish for a while until he gets settled and builds his new pond at his new place. He has around 50 goldfish (not sure if any are koi).


Here’s my setup:

• Pond is about 2,900 gallons (with the new addition I’m finishing up).
• It has an aerator and a biomechanical waterfall filter with air and bio balls.
• I just installed a new OASE BioTec Screenmatic 18000.
• I currently have 50+ goldfish and one koi of my own.

A few weeks ago, I had some construction done nearby, and they sprayed cork insulation on my workshop. Even though the pond was covered, it started raining and some of the spray-on cork ended up in the water. My fish have been in about 2 feet of water all this time while I finish the new addition. Unfortunately, I lost two fish with swim bladder issues during that period, but the rest are doing okay now.


Right now, my water isn’t crystal clear — I’m hoping once I get my skimmer reinstalled and the new filter fully running, it will clear up. I should be finished with the pond addition by next week.


The temps here are around 65°F during the day and 40°F at night, so it’s starting to cool off.


My main concern is how to safely take in my friend’s fish without risking diseases or stress for either group.

• I don’t currently have a quarantine setup, but I could possibly get a stock tank or something similar.
• I do have salt on hand (I’ve used it before when my koi was stressed).
• With the colder temps, I’m not sure what’s safe or effective to use to prevent any cross-contamination or parasites.

Any advice on the best way to introduce these fish safely (or if I should quarantine them somehow) would be really appreciated.


Thanks in advance for any help — I just want to do what’s best for both my fish and my friend’s until he gets his new pond up and running!


— Landry

 

[Lisak1]

#1 - Quarantine shouldn't even be in question. Thats a must. Both ponds could be full of thriving fish, but one herd could introduce something that the other herd has never encountered and it could lead to a mass wipe out situation. Not cool.

#2 - whether or not "any are koi" is a critical question. Goldfish and koi are not the same. We can discuss that at length but let's leave it at you need to find that out.

#3 - Once you safely add all these fish to your pond, do you realistically believe you will be able to sort them again? It'll just be a swarm of fish at that point. If no one cares then I guess it's fine, but 50 plus 50 will 200 if he takes more than a few weeks to finish his pond!

 

[Landman]

#1 - Quarantine shouldn't even be in question. Thats a must. Both ponds could be full of thriving fish, but one herd could introduce something that the other herd has never encountered and it could lead to a mass wipe out situation. Not cool.

#2 - whether or not "any are koi" is a critical question. Goldfish and koi are not the same. We can discuss that at length but let's leave it at you need to find that out.

#3 - Once you safely add all these fish to your pond, do you realistically believe you will be able to sort them again? It'll just be a swarm of fish at that point. If no one cares then I guess it's fine, but 50 plus 50 will 200 if he takes more than a few weeks to finish his pond!

This is a first for me but I'm not worried if they get mixed up as long as my Koi stays. What do you recommend I can put in this cold water to treat the fish. I will add my aerator and some pond water or should it be new water in the quarantine tank. If he has Koi which I doubt he does I already have one myself so I know they will be fine we have similar environments even though he lives 2 hours away. Thanks for the input now I need to get me a large tub/stock tank.

 

[addy1]

Amazon will ship a 300 gallon stock tank for less then buying and driving it home.

 

[Tula]

Has your friend considered setting up a temporary arrangement on his new property while he builds the new pond. I've seen lots of people move their fish and set them up in an index pool or stock tank. Hopefully he could even take some of his filter media to the new place.

Seems easier if he just sets up something himself, rather than having you do it, then having to move the fish later.

 

[WaterGardener]

I second the suggestion of an Intex pool. Your friend could set one up on his property or you could put one at your home. It would need different filtration than what comes with the pool, but that isn't hard to set up .

I would not mix the fix. Keep them separate.

Where are you located? I have a 1,000 gallon pool that I would be glad to donate if someone picks it up. It's in very good shape. I just don't need it anymore.

This time of the year, there might be some on Craigslist or Marketplace. Also, the price drops considerably on new ones as the weather cools down.

 

[j.w]

Wondering how big those goldfish are of yours and his? If large that's a lot of fish to add to your pond at once I'm thinking. I'd do the pool deal so not as much to worry about. You could use some of your pond water to the new pool to avoid the new pond symptoms. Or they could do that to a pool at their new place. Take some of their old pond water and start w/that. I would not add their fish to mine as if something bad happens you can't go back.

 

[Landman]

Has your friend considered setting up a temporary arrangement on his new property while he builds the new pond. I've seen lots of people move their fish and set them up in an index pool or stock tank. Hopefully he could even take some of his filter media to the new place.

Seems easier if he just sets up something himself, rather than having you do it, then having to move the fish later.

I mentioned this to him he said it will be at least a year until he gets a new pond built so I will check out an intex pool set up.

 

[Landman]

Wondering how big those goldfish are of yours and his? If large that's a lot of fish to add to your pond at once I'm thinking. I'd do the pool deal so not as much to worry about. You could use some of your pond water to the new pool to avoid the new pond symptoms. Or they could do that to a pool at their new place. Take some of their old pond water and start w/that. I would not add their fish to mine as if something bad happens you can't go back.

Most of my goldfish are small around 1" to 3" I'm not sure how big his are probably around 3" or 4". I haven't seen his pond in person but he gave me a few goldfish when I first got my pond going in 2022.

 

[Lisak1]

I know a member here who has had her goldfish in a temp pool for several years getting ready to build at a new home. Goldfish absolutely would not care. I just think you're taking a huge risk with both groups of fish by combining them.