# Lava rock



## Shamus.Flynn (Jun 11, 2014)

would Lava rock be safe to go into a fish tank? pet store just got some in and was just wondering if they alter the water in any way before I look into buying it.


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## ZooKeepersMenagerie (Oct 28, 2014)

I believe they are good. Some people recommend some because the holes provide places for the bacteria to grow/water cycle stuff.


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## Shamus.Flynn (Jun 11, 2014)

ya I seen that. some others say bad for scratching fish just wanted to ask what other people think of it. gotta do a major overhaul for my tank because the town I live in added something to water so I have very high ph now like 8.8-9.0 so have to change some stuff out to lower the ph in tank. probly going to end up buying a ro/di system


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## Mariostg (Sep 6, 2014)

I just bought a 35 liters of lava rock to make a bed for an over the top river. It's good to anchor plants that grow outside the water.
Creek above tank


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## Solcielo lawrencia (Dec 30, 2013)

Shamus.Flynn said:


> ya I seen that. some others say bad for scratching fish just wanted to ask what other people think of it. gotta do a major overhaul for my tank because the town I live in added something to water so I have very high ph now like 8.8-9.0 so have to change some stuff out to lower the ph in tank. probly going to end up buying a ro/di system


Did they add lime? If so, the pH increase is temporary because lime drives off CO2. Once it's aerated, the pH will drop.

Lava rock is inert so it's fine for aquarium use.


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## Cthulhu (Dec 18, 2012)

I grind the rocks together to make them smoother and remove rough edges that could hurt the fish.


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## Mike Letourneau (Nov 18, 2014)

I recently used lava rock in my tank and while it is very porous, making it a great site for bacterial colonization, it also leaves room for trapped air pockets inside the rock, making them much more buoyant than other rock. 

With that said, strong currents or fish that dig will make the lava rock something easy to move around and your once pre-constructed shape won't stay pre-constructed for very long.

I got the idea to silicone a bunch of the larger individual pieces together to form larger chunks. These proved more stable and less likely to move if placed in front of a powerhead. Siliconing the rocks together was a pain due to its labor intensive process but the results are "rock solid". 

The other problem I noticed with using lava rock was algae. The typical freshwater sucker-mouth clean up crew doesn't work well with a porous substance such as lava rock. They can't clean it well. I don't know how pet stores keep theres so clean. I would think shrimp would probably be your best ally against algae with lava rock.

I can't imagine that fish would rub themselves against it for the intention of injury, but, if they do......chalk it up to Darwinism.

Bump:


Shamus.Flynn said:


> would Lava rock be safe to go into a fish tank? pet store just got some in and was just wondering if they alter the water in any way before I look into buying it.


Lava rock - Inert and will not alter your ph in any way. 

I have the exact opposite problem. I have well water and I can't seem to keep my ph high enough. It always hoovers around 6.2-6.6.


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## roadmaster (Nov 5, 2009)

Lava rock too rough for fishes that like to root around such décor for food.
Could scrape the mouth's,bellies of fishes such as cory's,loaches,plecos.IME
Not sure this material makes better biomedia so much as it provides plenty of places for food/waste to become lodged and thus bacteria begins to work on the waste trapped therein.
Would not hesitate to use it in tanks with small tropical that don't scour over the surface while searching for food, and have seen some very nice tanks with this as hardscape.


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## Raith (Jun 27, 2014)

Believe it or not, I use it for my cichlid caves, no injuries yet, knock on wood!


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## roadmaster (Nov 5, 2009)

Raith said:


> Believe it or not, I use it for my cichlid caves, no injuries yet, knock on wood!


 
Yes, I have seen this as well as coral used in African cichlid tanks where the species is adept at nibbling algae and food bits from the rough surfaces.
Many of them have developed specialized teeth for this purpose.(along with inflicting damage when needed such as spawning).
I like large smooth stones for use with loaches,cory's, plecos that rasp on object's rather than nibble, or chew.


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## Shamus.Flynn (Jun 11, 2014)

would lava rocks be okay with fish like tetras? I do have 2 yoyo loaches and 2 plecos tho.


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## Diana (Jan 14, 2010)

Yoyos burrow into the substrate a lot. I would worry about them with a coarse substrate, but not a single (or a few) large chunks of lava. Plecos are the sucker mouth types. They generally won't latch on to something as rough as lava rock. Tetras are fine except for one thing:

Yoyo Loaches are predatory, and might chase the Tetras with the intent of eating them. In the chase, the Tetras might bump into the lava rock. The answer to this, of course, is to not keep small fish like many Tetras with Yoyo Loaches (or any other fish big enough to eat them).


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## Shamus.Flynn (Jun 11, 2014)

so far had the yoyo loaches for probly 4-5 months and haven't had any hungry loaches yet.


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