filter system pipes

[shook]

I am in the process of building an above ground pool inside a stone walled area the wall has a reinforced metal ring round the top and i am currently using shuttering to cast a reinforced inner wall. I am building an inner wall of the same to house the works. This wall must have the pump and filter in and out pipes cast into it and a skimmer at the top. I'm having trouble finding at what height to build the two pipes in. They both have to be in this wall, but can be 6 metres apart. The pool depth will be one and a half meters. I'm intending to put 50mm plastic piping in. The filter won't arrive for 3 weeks so building the pipes in now!