Is it okay to put any old logs or branches from a river in my fish tank?
I have one in the tank from when I set up my tank. It was out of a river but it was only small though about 50 cm long 20 cm thick. It floated for months then snuck to the bottom of the tank. I was gutted but it still looks nice.
I want to put one in a lot bigger in this time will it be okay to do?
I wouldn't as wood will absorb water and chemicals in it. You could do a bleach soak but then you'd have to do a big soak of clean water changing daily to get the bleach out.
Simple answer no it's not neccessary.