Gold fish resting too long at the bottom help!

[Pengchon]

Okay I have 10 gold fish, each are 1 inch long, 9 of them are having fun swimming around everywhere, but 1 of them is just constantly resting at the bottom, seems like he's sad, then theres another one that seems to feel sorry for him, so he goes near that goldfish all day just resting with him.
Now those two fish are always together in that same area, resting at the bottom. They never seem to move an inch.
I checked everything!
my pH lvl
my ammonia lvl
nitrite, nitrate
chlorine is free
My question is, why are the others having a great time, but that one fish is always seem to be resting? Is he sick?

 

[Roan Art]

Would you please post the numbers for the levels you tested? Ammonia, nitrites, nitrates, pH. We need those in order to help determine what may be wrong.

We also need to know how big the tank is and how long it's been running and how long the fish have been in there.

What type of goldfish are they? Pond, Fancy or Very Fancy?

Roan

 

[liv2padl]

unless you have these ten GF in about 100 gallons, they're going to do poorly. GF, even when small, need alot of water volume ... their metabolism and heavy volume of nitrogen waste discharge dictate this. successful GF keepers generally figure on ten gallons per fish when they're small and upwards of 20 gallons or more when they're larger.