joe

If i have a 2" pipe coming off the pump to the filters,can i use 2 1" pipes for the return,1 going to a bubbling rock and 1 under the water

Davej

Hi Joe

Is the filter a pressurised one? if not then the size of the returns is dependant on the amount of water your pump is delivering to the filters.

You can split the return into two but the size of the pipework needed will depend on your pump size.

Dave

Mattsville

Remember that 2 x 1" pipes are not the equivalent of 1 x 2" pipe. A 2" is roughly 4 times the size (in terms of cross section area) of a 1". So it all depends on how much flow you need to be going through them.
If you're using a powerful pump then I don't think 2 x 1 inch will cut it - if the filter isn't pressurised it may back up and overflow, and it if is pressurised then the small pipes will restrict your flow a lot.
2 x 2" might be better?
Other than that should be no problem having 2 returns - just need to make sure you can control the way the flow is split between the two - as I'm assuming the rock is higher than the mid water return - you might get less flow to that than you want.
Matt

joe

Thanks for the replies,as soon as i have construction finished and get final volumes and pump sizes i`ll know(or at least i hope you`s will point me in the right direction),so far it is looking likely to be around 30,000l capacity pond
9m x 4m x 1.3m deep