Where to buy large black lava rock? Create height in tank?

I want to get some large black lava rock for my next scape. By "large" I mean like pieces that are 3+ inches. The only place I've been able to find anything like this is my local fish store, but they only sometimes have them and even then, they're marked up as aquascaping materials/rocks. Wondering if anyone knows about hardware stores that might sell them large like that? Most hardware chains sell the small normal stuff for gardens and fire pits.
I want to create a retaining wall or just some height that can plant plants on and around. Most all rocks sold at the LFS are overpriced, and the rocks I've found locally so far are lightly colored. I'd like dark, affordable, preferably lightweight, rocks- hence large black lava rock. Or suggestions on how to achieve this in a way I might not be thinking of

 

If you have a landscaping store near you, they might have some.

 

Landscaping stores or someplace like Lowe's or Home Depot, hardware store, etc. Sometimes you can get even better deals by ordering on their websites, too.

 

Landscaping stores or someplace like Lowe's or Home Depot, hardware store, etc. Sometimes you can get even better deals by ordering on their websites, too.

Yeah I've checked those places but so far I'm only finding the small stuff unfortunately :/

 

I agree, Rockyard & Landscape companies are the way to go for finding great deals & more varieties of rocks.
A word of caution about Lava Rock usage. They are quite abrasive & have the potential to really carve up fish.
I learned that lesson the hard way.

 

I agree, Rockyard & Landscape companies are the way to go for finding great deals & more varieties of rocks.
A word of caution about Lava Rock usage. They are quite abrasive & have the potential to really carve up fish.
I learned that lesson the hard way.

So basically avoid loaches and the like.

 

I never advise against keeping Loaches, Lol. I keep quite a few.
My bad experience w/ Lava rock was with a big lava rock reef I constructed in a marine tank.
Realistically even lava rock becomes less abrasive if algae is allowed flourish on it.
There are just so many other rock varieties available, which are better suited for base rocks.

 

There are just so many other rock varieties available, which are better suited for base rocks.

I agree. The issue is finding dark rocks for an affordable price. There are a ton of aquascaping rocks at my LFS, but at $3.50 a pound for example, 1 large rock at 20lbs puts me at $70 bucks.... for a single rock. Whereas even at the same price per pound (though lava rock is usually even cheaper per pound), a lava rock of same size would weigh probably 5lbs- only $17.50.

I'm highly considering just getting a big bag of the small stuff and gluing a structure together. I hesitate to do that because of the permanence of glue, but it's sounding like the most affordable option considering what I want

 

I bought 200+ pounds of Holey rock at my local rockyard for 17 cents - 25 cents per lb. Big show pieces of Holey rock for sale on line goes for $100 - $200 a piece.
Don't waste your money at the LFS.

 

I bought 200+ pounds of Holey rock at my local rockyard for 17 cents - 25 cents per lb. Big show pieces of Holey rock for sale on line goes for $100 - $200 a piece.
Don't waste your money at the LFS.

I agree, people always say support local businesses. But to be honest, I don't have the money to.

 

This hobby is so very expensive unless you are aware of the financial short cuts.
It would have been nice if fish forums existed when I first started. I could have really used old timers advice.
I learned what I know through the school of hard knocks & blew a lot of money along the way. Lol.

 

I wpupd say a landscaping company would be your best bet. I doubt they will have the size youre after, but some larger ones with a hammer and chisel will probably get you what you are after