This clever little adaptation of a strong working pump was buried in the Bio-diesel Forum, it needs more viewing and use ! Adding it here:

http://www.permies.com/t/33523/biodiesel/world-famous-SBC-pump#340555

No good for aquaponics, it is metal

Love the SBC pump!  Will it work with laundry water?

I am designing a 'laundry to landscape' system on my hillside.  The first photo shows how a 1" pvc 'laundraduct' slopes down from my house to an existing 15 gallon surge tank. The green level line is from Sun Surveyor, a handy IOS app that gives an augmented reality view of the suns path and other useful things from your position anywhere on earth.

The existing laundraduct/surge tank system works but the area it feeds is too shady for a garden.  So I am hoping to water a garden which is about 50 feet away and 2 feet higher which gets good sun.

The second photo was taken with the elevation line at the top of the 2' tall stock tank. I plan to fill the 169 gallon stock tank with tire shreds I got for free on Craig's list to make an artificial wetland.  Again, the green horizon line is level with a 2" HDPE line running level for 50' along the sloping fence.  I am planning on using that to extend the laundraduct to a new shallow sump/filter located near the stock tank.  

My washing machine pump is already at the recommended limit specified by Art Ludwig (Create an Oasis with Grewater). Since this design seems so marginal I am looking for a way to augment my washing machine pump and get the water a little higher without shortening its life.

Any advice is welcome.
Paul

Automotive oil pumps (positive displacement gear pumps) are not really designed for a water environment.  Oh they'll pump the water fine, but you may end up with rust and corrosion problems.

Or not....hard to say.

But gear pumps are designed with (and must have) very fine tolerances and close fitting gears and end plates.  A little rust, a little abrasive action, this could damage the pump.


Alternatively a centrifugal pump does not depend on very fine and close tolerances to work.  Here's one from Northern Tool for 79 bucks:

http://www.northerntool.com/shop/tools/product_7738_7738


There are important differences, the gear pump is a positive displacement pump, meaning it will pump water, oil or air, and because of that is self priming.

The centrifugal pump is not self priming, so it needs to stay full of water and/or be below the water source for it to start automatically.

The Gear pump can produce far greater pressures if the water has to go up any meaningful distance, often referred to as the head.  It could push it up 40 vertical feet almost as fast as 4 vertical feet.

The centrifugal pump quickly loses pressure if there is much head.

Here is a similar application with a similar Harbor Freight centr. pump.  

https://www.youtube.com/watch?v=5_xduog_Kdw


Does that clarify anything?

Troy Rhodes wrote:Automotive oil pumps (positive displacement gear pumps) are not really designed for a water environment.  Oh they'll pump the water fine, but you may end up with rust and corrosion problems.

Or not....hard to say.


Does that clarify anything?

Yes, that clears it up.  I may build the pump to use as a utility tool to pump diesel, veg oil and water once in a while using a drill motor.

Meanwhile, back at the ranch, I may have come up with a partial solution to my problem.  

I am most worried about putting 140F water into the artificial wetland and hurting the biology, particularly plants.   I realized from looking at 'The better bell siphon'  https://www.youtube.com/watch?v=lyrvcCqv5V0 that a small storage tank that empties automatically when full may work.  A 4" diameter pipe 50' long will hold a laundry load of water and only adds 1/3 foot of head.  A bell siphon dumping into the stock tank will empty the pipe the next day/cycle allowing the water to cool and ensuring it does not stay for long. If we skip a day or two of laundry and it starts to smell, we can add water to trigger the bell siphon.

I am hopeful the output from the artificial wetland will be clean enough to use a clear water pump.  

Thanks for the clarification.

A "clear water" pump doesn't mind a little grit or sand or soft debris.  It just can't do rocks.

But the gear pump doesn't even like sand or other abrasives because of the close fit and tight tolerances.