what’s with all the thumbs down?

go to home depot or other gardening/home improvment store and pick up a bag of pea gravel.. it’s like $3 for a 30 pound bag
anything at a petstore is going to be overpriced… unless you wanted a specific gravel.. like black or some neon acid trip color

if you did mean live rock… it is rather expensive but there’s no real way around that… you can look around for someone selling an old tank or their rock… you can also mix it with base rock… basically live rock that’s no longer live
don’t buy your rock online.. sure it’s only $3-5 a pound but with shipping costs it comes out to more like $10

Fish Tank Gravels. The aquarium should be filled with substrate to a depth of approximately 2 ins (Math about 1Lb Per 1Gal), if no plants, and don’t want to spend alot of moneys on the gravels 1in can do too.
Cheap gravels, you can go to Lowes,Home depot or Menards get a 50lbs of smallst gravels thay got for under $5+tax, But you got to wash them VERY VERY VERY good b4 u use into the fish tank.
Good luck Hope this helps!

What kind of rocks? Live rocks, for saltwater? Do you just want decorative stones on the bottom?

If you want the latter, you’ll have to find out what the rocks are made of, and research to see if they’ll have any effect on the pH and hardness of the water.

Aquaria are made of more than just tank, stones, and fish. For a 75 gallon freshwater aquarium, you will need the following things:

-Tank
-Stand (must be able to hold 850 pounds or more of weight)
-Location (must be away from window and air vents, and reasonably close to an outlet)
-Lights
-Filter
-Heater (if you want tropical fish)
-Gravel (real or fake)
-Plants (real or fake)
-Fish
-Fish food
-5 gallon bucket
-Airline tubing or some other way to remove water from tank
-Dechlorinator

Check out this article, it’s on setting up a 75 gallon tank:

well rocks.. mhh go to home depot and buy some river stones they are liek 10 dolalrs per 40 pounds or so get like 2 or 3 bags and fill it up although it would look nicer with gravel or sand :p

hope you change ur mind hope i helped also

I would put in enough rocks to cover the bottom of the tank which you can get at Wal-mart(don’t get the fish there) or PetCo