I appreciate your kind suggestion my friends,
I have to confess that i chose the red plant wrongly. i thought it is Ludwigia respen that is so easy to care but in fact it is Alternanthera , so hard to be adapted!
if it adapted and grew healthy , i would move it to the back.
about Rocks. yes i collected them myself. In suburbs of our city many mines of rocks (especially for decoration and constructing building) can be found.
and about heater, it is in quarantine tank for making warm the Rasboras. when the tank is cycled,i will add both fish and heater.
thank you for taking your time