[musho3210]

Whats a good type of rock to grow algae on in a freshwater tank. I want to grow green algae or diatoms for my ottos. I will get 2 rocks, one stays in the tank, one is put outside where algae grows. I'll probably rotate once or twice a week. Could i use pebbles found outside my house, or are they too dangerous. I dont mind them lowering my buffer capasity cause the fish i have like a low Ph.

 

[Lauri]

Rocks found outside your home can be okay just make sure you scrub them well under hot water no soap. Our 55 gallon tank has several rock structures in it and all the rocks are from our backyard.
You could also try a piece of lace rock that grows algae well, you might find that at your lfs. Good luck

 

[musho3210]

ok thanks