I am in the process of building a new pond and have been given lots of decent sized plants. The only problem is they float, I cant remember the name of the plants but they are tall and have yellow flowers.
I have weighed the plants down with large stones but now worried it may be limestone which I gather is bad for fish or maybe its sandstone?
Does anyone know how I could identify it?
Maybe when I get home I could post pic's for you guys too look at :D
Take a piece and drop vinegar on it. If it starts to fizz and bubble, it's limestone. Another way is to put a small piece in a container of water alongside a container with just water in it. Test the pH after a couple of days. If the one with the rock in is higher, the rock is dissolving an raising pH, so therefore limestone.