Rock for my Axies

[lorraine]

Just wondering what kind of rock is suitable? I will be upgrading to a 120 cm tank in the near future and started thinking of some ideas, I would really like to have something like in the picture below as a feature for the Axies to climb and hide in. Any advice would be great. Dont want to put anything in that is going to be bad for the water or the Axies.

 

[helobed]

You would need to consider if the type of rock would leach potentially harmful chemicals into the water (but unlikely if bought from a reputable fish shop.) The other thing would be to make sure it doesn't have any sharp edges.My axies love to squeeze into tight spaces and have very fragile skin.

But apart from that I cant see why not