Sick or injured goldfish

[Lpbrady]

My son wanted to try fish. We picked a couple goldfish out and noticed this one had a wound on the drive home. After trying to research online, we decided to move him into a separate bowl. It has six cups of water, 1 1/2 tsps of salt, 1 drop of methylene blue. We used distilled water. There isn’t a sponge or filter, he’s literally just in a glass bowl.
We are completely new at this and bought a test kit that will test everything but that is for the big tank and I’m just trying to figure out what to do with this one. Our plan from here was to put him back in with the others at feeding time and do the same salt dip tomorrow.
Is this a good plan? What should I actually be doing? Is this an injury or disease or parasite? I thought it was an injury, then maybe red spot then maybe some type of worm. So, I clearly have a handle on this. Any tips appreciated.

 

[Aiken Drum]

Maybe a tumour or ulcer?

Im assuming you are US based? If so not much point in me suggesting medication as you will have access to better medication than we do in the UK. Look for something to treat skin conditions.

Out of interest how big is your main tank? Goldfish get very big, are very messy and need big tanks.

 

[Lpbrady]

Yes, US based.
Ya, our tank is going to be waaaaaay too small. We got five goldies, my son says they are comet, and we have a 10 gallon tank. I guess this is a huge rookie mistake. Maybe we’ll make the outdoor pond we’ve considered for years ��

 

[Aiken Drum]

Probably a 75 to 100 gallon tank minimum for those fish as a permanent home, with a filter rated for double that. They will outgrow a 10 gallon very quickly. I would also say cycling a 10 gallon tank with that much bioload is going to be very difficult. You may be into daily water changes to keep the water safe in the short term.

How about returning the goldfish and getting something more suited to a 10 gallon tank?

 

[Lpbrady]

I am 99% sure the pet store does not take returns on fish but it could be worth looking into

 

[Aiken Drum]

I am 99% sure the pet store does not take returns on fish but it could be worth looking into

They shouldnt be selling you fish without ensuring you can properly care for them first. Did you get the tank and other equipment all from the same place? They have some responsibility here.