Hay Dan,
Here's a flow test report I did some time ago on some ebay bought bilge pumps and a super cheap pump.
I was testing them for a similar situation as you have. I have a house about 400m from where I digging.
Hi All,
Well, here are my results from testing my bilge pumps today.
All these pumps are sold as 2000 GPH. It is unclear if that is imperial or US gallons.
I have assumed they mean US gallons and that is what I have based my calculations on. If I based my calcs on Imperial gallons the results would look appalling.
So to my observations.
All pumps had three 15 second runs from one 60 liter bucket into a 25 liter bucket.
The water quantity in the 25 liter bucket was then accurately measured, multiplied by 4 to get L/min. then again by 60 to give L/hr. then converted to US GPH.
The best results for each pump are as follows:
Supa cheap 2000 GPH pump 925 US GPH
ozplaza.living 2000 GPH pump 1014 US GPH
Modified ozplaza.living 2000 GPH pump 1096 US GPH
So the results speak for themselves.
What you think you are buying is not necessarily what you get and unless you do the test you will never know.
I thought the supacheap pump would be better quality than it is. Looking at the impeller set up I thought it would flow better than it does.
When I opened the box the strainer was broken so it's back to Supacheap tomorrow.
I was going to run 2 of these pumps on my stealth banker project (see it running here
https://www.prospectingaustralia.com/forum/viewtopic.php?id=640&p=2 post #26) but I can't see me having enough water flow from 2, I may have to run all 3 to get the flow I need and that will cause battery run time problems. Bugger!!!!!!!!
Hope this little test has some value to someone.
Don't forget if you buy the ozplaza.living ebay pumps that you need to disassemble them and seal them up with silicone before you use them because they leak water into the motor case and will be junk in short order if left with water in them.
Cheers
Mick