How many fish in the tank and their size? There are 5 fish in this big blue breeding tub. i dont know how big it is but im sure its enough.
Any medications added to the tank? Nope
Add any new fish to the tank? No new fish
What do you feed your fish? I feed the fishes these floating pellets that the shop person recommended...
Any unusual findings on the fish such as "grains of salt",
bloody streaks, frayed fins or fungus? Clamped fins! Scales dropping off! white slimy looking stuff growing on it....
Any unusual behavior like staying
at the bottom, not eating, ect..? Not as active as usual.

Sorry i couldn't get many details....My mom thinks it might be the water as some relative of ours also kept goldies and one day when he changed the tank water all of em died.

You'll need to get your water tested and try to get the measurements of the tub you're keeping them in. Water can be the life and death of a fish, so it's very important that we know those details.

In regards to water-changing: Be sure to detox the water with some type of dechlorinator and to match the temperature & pH as closely as possible so that the fish aren't shocked by sudden changes.

Maybe you can tell us a bit about the way you take care of your fish, such as how often you do water changes, and how much water you change at a time. Also, whether you have a filter on your tub and what kind of filter it is. Whether you use a water conditioner, and if so, which one. Also, how long you have had the fish.

Then, as Nenn suggested, measure the tub. The length, width and height.

That will help us make suggestions as to what might be wrong with your fish and how to help them.

If you can, you could also take a sample of your water to a fish store and get it tested. Most fish stores or large pet stores that sell fish will test water for free. Ask for the numbers, not just good or bad and post the numbers here. That will give us lots of clues as to what the problem might be.

I hope to hear from you soon!

Can you update us?