Cloudy goldfish tank

Hello ! I have one goldfish, who was in a 20 gallon tank. The tank started leaking, so I had to get another tank quickly, and ended up with a 10 gallon. I got a new filter, and set it up 2 days ago. The goldfish did really well, but this morning, his tank is cloudy. Any suggestions on what I should do to clear up the water ?

Hi, there! You got a new filter? Did you use the filter media from the old tank to cycle the new one? If not, your fish is in an uncycled tank which creates toxins to harm the fish. Let us know if you used the old filter media before we proceed with help. Also, 10 gallons will not do for a goldfish. It must be at least 20G for one fancy goldfish. If it’s a single tailed goldie, it needs to go in a pond as they grow up to 18” long. I raise and breed goldfish and will be happy to help you.

Hi ! Thanks for the reply! No, I used brand new filter media, the old filter was not able to be saved. It was really old and disgusting. What can I do now to clear up the water ? I can get him a 20 gallon, just not yet, so in the mean time, what can I do ? He seems healthy, and not stressed. Eating well !

Also, I believe he’s a fancy goldfish. I’ve had him for almost 4 years ! He’s got a double tail

Yes, he’s a fancy or fan tail. For future reference, you should have pulled off all of the filter media from the old filter and stuck it behind the new media. You now have an uncycled tank which is dangerous to your fish. The old media would have given you an automatic cycle. You will now need to do daily water changes and test your water daily with a freshwater test kit. It is important to watch the ammonia, nitrite, and nitrates until tank is cycled as these are toxic to the fish. Please read on “fish in cycling” to better understand what I’m talking about. You will also need to use Seachem Prime after each water change to bind the ammonia, nitrite, and nitrate to keep them from poisoning your fish. It will take several weeks to cycle the tank and the daily water changes will be necessary. Again, read on the fish in cycle procedure and get back with us. Here to help.

Thank you for helping ! I just did the first water change, about 25% of the water. I use water conditioner, and will get the freshwater test kit and seachem prime when next im in town, which will hopefully be tomorrow!

The milky cloudy water is caused by bacteria living off uneaten fish food and waste in the water. These are different bacteria to what lives in the filter and keeps the water clean.

If you had transferred the old filter or filter media into the new tank this wouldn't have happened. Because you have a new filter with new media, there is no beneficial filter bacteria to keep the ammonia and nitrite levels down and this is the result.

The best thing to do is reduce feeding to a couple of times a week and do a 75% water change and gravel clean the substrate 4-8 hours after feeding. You should also monitor the water for ammonia and nitrite and do a 75% water change and gravel clean the substrate if you get a reading above 0.
Make sure any new water s free of chlorine/ chloramine before it is added to the tank.

In about a month's time the filter should have developed the good bacteria that keeps the water clean and you can increase feeding to once a day and do a 75% water change and gravel clean each week.

How long do I need to do water changes for ? I’ve been doing 25-50% for almost two weeks now. I’ve been doing the water changes every day to every other day .

You need to do a water change every time ammonia and/or nitrite are above zero. And the amount of water needs to be big enough to get them down to zero.

Once ammonia and nitrite stay at zero, you need to do a weekly water change.
However if this is still the 10 gallon tank (which is too small for a fancy goldfish, they need at least 25 gallons) then you should really do 75% changes twice a week. Goldfish are messy fish and in such a small tank nitrate will build up quickly. And get a bigger tank asap.

I agree. Once you get 0 ammonia and nitrite, you can begin doing water changes to keep your nitrate below 40. I would normally say to keep it below 20ppm but anyone that has goldfish will know how difficult that is. I do a mid-week w/c of 50% and an end of week tank cleaning including syphoning the gravel, scrubbing sides, and cleaning filter media, (filter media is done every 2 weeks.). I also do 75% water change on cleaning day. Your tank is entirely too small for one fancy goldfish. The actual guidelines are 20G for first fancy and 10G for each additional. Please upgrade your tank ASAP. Check out the pics below. The first fish is only 10 months old, born in my home. She is now approx. 4.5” long. The other pic is the mother. I bought her when she was 1.5” long. In 19 months she has grown to a approx., 7” long. It happens quickly so don’t waste time upgrading your tank. Mine are in a 55G. Goldies are very sociable fish and benefit from having another goldie with them. I would suggest upgrading to at least a 29G (preferably 40G) and get a friend for your goldie. Good luck!