Correct pipe diameter for 4k flow?

[yesman]

Just want to check a couple of points.

With 4000 lts of flow needed for screen(30in wide), is 25mm pipe size diameter adequate or would 32mm be better and can it be soft tubed from pump to 25mm screen holding hard pipe section?

The water will be pumped from the under tank sump to remote scrubber box screen 5 meters away and return by gravity through 63mm pipe.

Thanks.

[SantaMonica]

3/4 inch inside diameter will do it, although 1" would be a little easier on the pump.

[yesman]

Would that include making the 'screen holding' hard pipe section 1'' inside diameter too?

[SantaMonica]

3/4 inch works great for the screen holder. If you don't cut cross-slots, the water will have more pressure in the pipe which may help flow (although there is a bit more chance of algae clogging the slot, and spraying... so keep the slot clean).