Big Black rocks for Aquascaping, what to use?

[Stara'lfur]

I'd like to have a bit more hardscape in my aquarium, and I want some big black rocks to help fill it in. What type of rocks do you recommend, and where can I find them or buy them? I'm hoping there are cheap ways to find aquarium safe rocks without necessarily going to an aquarium store.

Also recommend any type of black/dark grey aquascaping rocks... river rocks, big rocks, etc. I'm always looking for new ideas!

 

[GEV83]

I got all my rocks from outside I never bought any. Just make sure to clean them properly before entering them into your tank. Also I believe if you put vinegar on them and they start to fizz then they will raise your PH levels.

 

[SubRosa]

Too bad you're on the wrong coast! Right around the corner from me is a spot where a truckload of black shale got dumped. I have several pieces that are cube shaped in sizes from 8"to 12", plus some slabs 4"thick that are over 100lbs each. And there is still a ton (several tons actually) left. Pieces range from hand sized to ones you'd need a backhoe for. Slate and shale are the normal black rocks unless you like it shiny then obsidian is the way to go. Try a landscape supply place or a quarry in your area. Buying in an LFS you'll be paying $2 lb which is insane.

 

[bazil323]

Yeah, try landscaping supply places. Yes, ger1023, if you put the rock in vinegar (or drop vinegar on it if it's a large one) and it fizzes/bubbles, it will raise the pH.

I've gotten most of my rocks from my yard.

 

[247Plants]

Too bad you're on the wrong coast! Right around the corner from me is a spot where a truckload of black shale got dumped. I have several pieces that are cube shaped in sizes from 8"to 12", plus some slabs 4"thick that are over 100lbs each. And there is still a ton (several tons actually) left. Pieces range from hand sized to ones you'd need a backhoe for. Slate and shale are the normal black rocks unless you like it shiny then obsidian is the way to go. Try a landscape supply place or a quarry in your area. Buying in an LFS you'll be paying $2 lb which is insane.

I would worry about the shale. In my area (Long Beach CA) I cant use it because of the oil content. I do find a lot of fossils in it though.

 

[SubRosa]

Another example of Cali's screwed up geology! No oil slicks in my tanks so far!

 

[Notophthalmus]

There are some dark granites as well. Don't worry too much about the acid test; limestones and other carbonates are harmless unless you are going for a softwater setup.