The Puffer Forum

what type of rocks are acceptable for freshwater aquariums. i have lots of ideas for a reshuffle but dont want to spend the £££s on the rocks if there is a free option? now i know limestone,sandstone and chalk are out for obvious reasons what could i find for free? the cheapest rock in my lfs is £2 per kg which is working out expensive for the quantity i need

for FW you can use almost anything. Most feild stone will work. When chesking the stone look for rust marks which mean an iron deposit and pass those ones over.

So basically any good solid rock? Maybe Flint? Brick?

A great test for whether a rock might be safe for a FW aquarium is to pour a little vinegar on it. If it fizzes, don't use the rock.

bertie 83 wrote:So basically any good solid rock? Maybe Flint? Brick?

brick, being red, may contain iron

Pufftastic wrote:A great test for whether a rock might be safe for a FW aquarium is to pour a little vinegar on it. If it fizzes, don't use the rock.

vinegar will make limestone (commonly used in aquariums) fizz

so limestone is ok? does it not discolour the water?

eieio wrote:vinegar will make limestone (commonly used in aquariums) fizz

Good to know -- thanks! So "bad rocks fizz" doesn't apply to all of them.

I've read that limestone can help stabilize pH, and that as long as you do regular water changes, it shouldn't be harmful to fish. I have two large pieces of Texas holey rock, which I believe is limestone, in my puffer tank.

shouldnt be would leave me a little paranoid.....lol

Personally, I only use inert rocks in FW aquariums. Slate is a great option - not only is it inert, but it comes in good shapes for aquascaping. I've found it very effective for making caves and hiding equipment at the same time. As a bonus, it comes in a few different colors.

thought about slate but its expensive, will prob get a few bits tho

I was thinking of getting some Ice Rock. In real life It looks more like salt crystals than in the photo below:-

Just remember--porous rock is what you want for successful filtration/bacteria growth, in a marine aquarium.

Pufferpunk wrote:Just remember--porous rock is what you want for successful filtration/bacteria growth, in a marine aquarium.

I think this is for his FW tank isn't it?

that is correct f/w. where did you see that so cheap its £4.50 per kg near me