Will Volcano Rock Hurt My Fish?

[KeegansTropiks]

Hello all, I got a bargain on volcano rocks and thought it would be cool to create a cave with moss growing over it in my 8 gallon betta tank.

I’ve never used these rocks before and they feel somewhat sharp out of the water. I want to know if these rocks will cause my bettas fins to tear or cause him injuries if he scratches himself against it.
He is currently healing from fin rot aswel so I’m not sure if this is really a good idea….

I’ll send pictures of the rocks and of the tank I plan on putting it in.
Also will these rocks leach any harmful contaminants into the water? (I will boil them before adding too)

Any response and recommendation will be helpful thanks

 

[DoubleDutch]

Doesn't look like it contains metals etc..... I'd use them. IMO fish aren't made out of wax and they're not stupid. As long as you prevent wedging when in panic for instance

 

[A201]

Lava rock is aquarium safe. I used big chunks of lava rock to construct a reef in a marine tank. Despite it's rough surface, the fish did just fine.

 

[RayClem]

Volcanic rocks, also called igneous rocks. are produced as molten magma cools and crystalizes. Depending upon the composition of the magma, you can get a variety of rock types. Silica (quartz and feldspar) is usually the most common component, but there can be carbonates, metals such as magnetite (iron oxide) and corrundum (aluminum oxide) and even kimberlite from which diamonds are sometimes extracted.

Some forms of igneous rocks: lava rock, pumice, and perlite, develop a very high internal surface area as they cool making them ideal for use as biological filter media.

Because of the way igneous rocks are formed, they are usually too hard to dissolve fast enough to cause any problems in an aquarium.

 

[Flyfisha]

The lava rock I am familiar with from the New Zealand and Australian volcanos will definitely scratch glass if you are not careful moving it around.

 

[RayClem]

The lava rock I am familiar with from the New Zealand and Australian volcanos will definitely scratch glass if you are not careful moving it around.

Correct,

Glass is about 5.5 hardness on the Mhos scale. Silica is 7 on the scale, so it will scratch glass. If the ignious rock also contains corundum (aluminum oxide), it is even harder at 9 on the scale. There are very few things harder than corundum: silicon carbide, boron nitride and diamonds are the most common.

 

[KeegansTropiks]

Thank you everyone for your responses !!

I used a nail filer to smooth down most of the sharp and rough surfaces and I’ve added it to my tank.

Looks great in my opinion, I also removed 1/3 of the gravel as I’m not trying to carpet the fore ground anymore.

I’ll attach a photo of what it looks like currently.