My goldfish keeps rubbing against the rocks

One of the reasons a fish may rub himself on the rocks is because he could have contracted ich. Does the fish have any white spots on him?

Be on the lookout of ICK (small white spots). When a fish scrapes its body against objects it usually means that there is an ICK out break in the tank. Yes they can die from it, if it’s not caught in time.

There is a lot of medication available for ICK, I use Mardel Maracide. You should only use Mardel Maracide if you have a spare or hospital/quarantine tank available, because it will stain the silicon (the aquarium glue that holes your tank together) blue.

I wish you the best of luck!

Or external parasites.

You also may have flukes which get into the gills or on the rest of the body, gills are more likely though.

First try some salt, a generally mild remedy for many external problems. Look up the dosage, I think something like 3 teaspoons per 5 gallons.

Gill flukes are difficult, search for Puregold site to read about them. There are interesting remedies as well as standard (harsh) medications for that.