Simply Koi and More Koi

Just wondering if I can make use of a piece of pipe that has come spare at work... It is 315mm diameter and just I under 3 meters in length, grey colour not sure the exact material but a version of plastic!!! It is unused and free... If I cut it to shorter lengths? Could I make some sort of trickle ...

Thanks all for the reply's - i think i might feel safer with the white vinegar.. or will it not attack as quick as descaler?, would be very worried about leaving any trace of either solution in there even after many rinses as to not harm the fish or the eco system.

My Elecro 900 2KW heater has suddenly started to play up (cycling effect) it cannot make the preset temp before it keeps going back to the standby mode. It was thought prior to removal of the unit that lowered flow from the water pump maybe causing the flow switch to be causing the false switching.....