I’m sorry for your loss. In high goldfish keeping we actively quarantine fish for up to 2 weeks before adding to our show tank to prevent additional stress or contamination of fish. What likely happened from what you described is internal parasites or possible body or gill flukes. When quarantining fish for 2 weeks, the first week is dedicated to removing any unwanted internal and external parasites through the use of a combination of medicine and salt. Additionally, no feeding should be performed for the first 3-5 days. The second week is for observation. All throughout this time frame, water is changed daily but medicine and salt etc is re dosed only for the first week of treatment. Treatment continues only if fish is sick after the first week. There is no filter on the tank and only an air stone is added. pH should be kept the same as all other goldfish at about 7.8-8.2. This can be buffered by baking soda if necessary. Only if the fish passes through 2 weeks with no issues do we add to the main tank. It does not matter if the fish has been “quarantined” in the shop. Your tank’s natural bacteria is different from that of the shop or the farm the fish came from, it is necessary to follow these steps to give your fish the best chance of survival anytime a new fish is purchased.

Oh man I'm sorry. I hate losing Fish!

Aww Chris I am so sorry to hear the sad news. It is very stressful moving your fish. 😢 I moved all 16 of my goldfish last week. They have been in their new home for 3 days and I am keeping my fingers crossed that they will all survive.

I’m so sorry for your loss my goldfish recently just passed away I hope for you and your goldies the best ❤

Our hobby is very stressful sometimes, good luck with the tanks m8!

So sorry for your loss Buddy

Can you make a video showing all your tanks and your fish by name?! 😍 I didn’t even know your goldfish had names 😅

I found Koi to be suprisingly hardier than Goldfish I’ve got high end koi too Sakai , Dainichi , Momotaro, Oya etc Sad you lost that big beautiful Oranda . Moving fish is always a lottery

Hugs 🤗 I spent yesterday morning with my most mature lionhead ranchu with bad swim bladder but after some quick action I managed to save her she’s up and about today. First fish I’ve brought back from the brink…but often it’s hard to rescue dying fancies

Super shame mate, sotimes some just get a little weak from the move. Onwards and upwards

About adding a power head to the simple budget tank?

Hi FGF. What are your filters on your heavenly stocked goldfish tank 👍😊

Sad news. I am so sorry.

Sorry to hear that! How about a possible oxygen crash? I’m sure it’s ok but I’d always have an air stone in there anyway

I lost a pearscale last month so I feel you

Sorry you lost him.

You say it’s a coincidence but how do you know? It’s a big concern.

Sorry to hear. Its probably because you messed with the tank. Sometimes I think once it's established leave well alone.