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Actually this is a good idea! I would however, make sure that the water temperature is the same as in the already running tank, so the good bacteria in the filter do not die. But , yes you can definitely do this without having to wait.
Updated on August 12th, 2025
Check the water chemistry and quality first. Poor quality can predispose him to infection. Use a home test kit or submit a water sample for testing. Your local Petco may do this for free or for a small fee. If ammonia and/or nitrite levels are elevated, perform partial water changes until both read 0 ppm and nitrates are 20 ppm or less. Use only conditioned water that is temperature matched to prevent further stress or shock. Providing pristine water quality is the foundation for treatment and healing. Check the water temperature since low temps can affect appetite and activity in fish. If the water is too warm, it can also affect activity since warm water does not hold as much oxygen as cooler waters. Fast the fish for 2-3 days then feed tiny bits of cooked and shelled green peas. This will aid in defecation if there is constipation. Plain aquarium salt (not table salt or Epsom salt) can be used for most fish as a general tonic to reduce stress, improve gill function, treat minor in
Updated on August 12th, 2025
Check the water chemistry first. Use a home test kit or submit a water sample for testing. The local pet store or fish store may do this for free or for a small fee. Aim for an absence (0 ppm) of ammonia and nitrites with a nitrate level of 20 ppm or less. Perform partial water changes as needed to stabilize chemistry and/or to improve water quality. Use only conditioned water that is temperature matched to prevent stress or shock. These fish produce a larger than average bio-load (wastes), so strong filtration is a necessity. The filter should be rated for at least twice the volume of the tank. The size of the tank may also be an issue. When keeping koi, tanks or ponds in the hundreds (or even thousands) of gallons are common. The number of fish in the current tank is too high. Consider getting multiple tanks or a significantly larger tank. 9 goldfish would need at least a 100 gallon tank. The additional koi increases this number.
Updated on August 12th, 2025
It is possible the tank has not cycled properly which results in high ammonia and nitrite levels which can kill fish. Allow the tank to run, without fish, for at least 4-6 weeks. During this time, use a home test kit or submit a water sample for testing every few days. The local Petco may do this for free or for a small fee. What you are looking for is to have ammonia and nitrites at 0 ppm and nitrates at 20ppm or less. pH can hover around 7 for most community fish. Avoid large, rapid swings in pH though. What is happening in the tank during this time is that beneficial bacteria are populating the gravel/substrate and the filter. These bacterial populations are responsible for the Nitrogen Cycle. This cycle breaks down wastes from fish, uneaten food and plant matter into by-products that are filtered out or dissipate. You can "cycle" a tank with fish, however this increases the risk of loss. Once your tank has cycled, you can add fish. You will still need to monitor water chemistry a
Updated on August 12th, 2025
Thanks for reaching out. This problem is perplexing, but possibilities include fungal or bacterial overgrowths. A good cleaning might help to alleviate your problems. Continue to test water quality and correct problems. Sometimes the over-growth of anaerobic bacteria (those which grow in low or no oxygen conditions, at the bottom of the tank), can form strange formations of detritus. Submitting a sample to a lab might help determine an answer. Good luck.
Updated on August 12th, 2025