geodes

[The-Wolf]

I saw this and thought that it would look great in one of my tanks
I was wondering if this would be harful to the fish?

geode

 

[appleblossom]

I dont see how it would hurt them chemically as it is made of agate, but I would be concerned about the rough edges inside. If one of your fish swam in the wide gap on the right, (assuming you got one a similar shape to the one shown) swam to the left, and then couldnt get out as the entrance is narrower, it would probably struggle and damage itself on the sharp crystal edges inside

Depends how big your fish are, and what the geode you get is like, but I would be a bit wary myself...

 

[Lateral Line]

Agate is simply banded quartz, the same material as the majority of sand and gravel. Those look to be artificially coloured however, there are a lot of those about. I expect they would chemically/biologically be harmless, but would expect some of the vivid colours to fade over time.

A lot of geodes/crystal groups would be very bad in a freshwater tank. The commonest "crystals" you find are CaCO3 and will harden your water and raise your pH. If any of these crystals fizz when you drop acid, like vinegar for example on them, they have no place in a freshwater tank unless it is an African Rift Valley type set up where the high pH is an advantage rather then a problem.

Many others are heavy metal salt crystal, Cassiterite, Sphalerite, Blende, Pyrite, etc., these do not readily react with vinegar but are undesirable in the tank. If you run lower pH tanks, espeacially so.

The comment about sharp edges is very valid.

 

[Max Action]

I have a smallish geode in my tank - it's cool when the fish and snails go into it. No injuries, no deaths, no ill effects. I also have a lot of agates and quartz in there ... the tank would be cool to look at even if the fish weren't there ...

 

[fishdudein]

As kids, we used to go out and find these rocks, bring them home and crack them open with a hammer. You don't get the smooth polished outside cut area, but they were very pretty crystalline rocks all the same. Of course, I couldn't help but put a couple in my tanks, and never experienced any problem from them. If you ever experience an algae problem in your tank, though, I can tell you from personal experience that those inner crystals have so many nooks and crannies that you will never get them clean.

 

[The-Wolf]

Thanks for the relpys
i don't think that i will bother