Moving water with 3" trash pump

Hello All, I hope I am in the correct forum location.

I have a 3" predator trash pump from good old harbor freight. I need to move water about 600 feet across a fairly flat run.

My suction head would be about 6 feet, with my total head over the 600' run +- 5 feet. From my quick calculations it makes about 40psi at that head with the 290gpm.

I am thinking about running 100 feet of 3" firehose, reduced into 50' of 2" firehose, and then the remaining 400' in 1.5" firehose.

Would the pressure loss through this system be too great that the water will barely come out at the end?

Theoretically I feel as if this system will work, but before I go about buying more hose I am hoping someone has better knowledge and can help me.

I have read numerous forums saying that the trash pumps are not high psi, not good for this task, etc.

Hoping someone can provide some knowledge! Thanks in advance.

Hi Thomas,

Welcome to Permies.

Hi Thomas, welcome to Permies.

Good questions! It would be helpful to know how much water you want to move, and how fast. I assume it is a lot or you would not be buying fire hose. I also don't know your time vs. cost calculation, which determines your method. (Slow and steady often means cheap and effective, depending on the circumstance.) And is this a one-time transfer, or will it be ongoing over time?

I'm not an expert, but I don't think a total uphill slope of 5ft is a major problem. Trash pumps are more focused on volume and less on pressure, as far as I understand them. The fatter the hose, the better the volume.

Personally, the first thing I would do is test how far uphill your pump can push water. The higher the better, of course.

And then I would consider the best method to transfer from A to B. If this is an ongoing thing, a rapid uphill pump plus some sort of trench/swale that drains to B via gravity would be highly efficient.

But this is all speculation -- we don't know the problem you're trying to solve. Help us out! Details please!

Douglas Alpenstock wrote:Hi Thomas, welcome to Permies.

Good questions! It would be helpful to know how much water you want to move, and how fast. I assume it is a lot or you would not be buying fire hose. I also don't know your time vs. cost calculation, which determines your method. (Slow and steady often means cheap and effective, depending on the circumstance.) And is this a one-time transfer, or will it be ongoing over time?

I'm not an expert, but I don't think a total uphill slope of 5ft is a major problem. Trash pumps are more focused on volume and less on pressure, as far as I understand them. The fatter the hose, the better the volume.

Personally, the first thing I would do is test how far uphill your pump can push water. The higher the better, of course.

And then I would consider the best method to transfer from A to B. If this is an ongoing thing, a rapid uphill pump plus some sort of trench/swale that drains to B via gravity would be highly efficient.

But this is all speculation -- we don't know the problem you're trying to solve. Help us out! Details please!

Hello! Thank you for the reply.

I am basically just trying to move as much water as possible, I have several food plots that I am planning on watering by hand with 1.5" fire nozzles.

The Nozzles run at 60GPM max so I am basically just hoping to see if theoretically the hose at the end of the 600' would produce 60GPM.

I know it is hard to calculate / speculate without PSI, Pressure loss, etc. Just looking for a theoretical 'yes' while I wait for the snow to melt so I can test it all.

Thanks!

Hey Thomas. I don't know how large your food plots are. But 60GPM sounds like a volume that would wash plants and soil away in a flood. Unless you have a plan to mitigate that.

FWIW, I find that moving water from one pond to another garden-side "pond" (or set of barrels, or a 1000L tote chopped in half) is by far the most efficient. It allows me to move more water by hand, more quickly and precisely than any hose could (because you have to make sure the hose isn't being dragged over your plants).

This is of course for my vegetable gardens. An orchard would be a different thing entirely.

Douglas Alpenstock wrote:Hey Thomas. I don't know how large your food plots are. But 60GPM sounds like a volume that would wash plants and soil away in a flood. Unless you have a plan to mitigate that.

FWIW, I find that moving water from one pond to another garden-side "pond" (or set of barrels, or a 1000L tote chopped in half) is by far the most efficient. It allows me to move more water by hand, more quickly and precisely than any hose could (because you have to make sure the hose isn't being dragged over your plants).

This is of course for my vegetable gardens. An orchard would be a different thing entirely.

The nozzle would be aimed at a large angle to mimic a rain sprinkler.

I have a 2” pump.   I pump the water into a 150 gallon tank and use gravity to move the water from the tank to the garden.   By pumping water into a tank elevated a few feet, you might avoid some of your water pressure concerns.  You would certainly save on some pricey hose with the trade off being the cost of the tank.

Thomas Walter wrote:The nozzle would be aimed at a large angle to mimic a rain sprinkler.

Hm, interesting approach. Personally, I would do a small scale test before committing to the whole project. I'm still worried it's a lot of volume for soil to absorb all at once.

I don't have numbers in psi or gal/min for the following, but it works for a 60 X 60 ft garden.  The photo below shows the pump (2" intake) that draws from water that is ~ 2 ft below pump placement.  From there, already stepped down to garden hose that goes up-hill (~10 - 12 ft gradual incline) over a distance of about 200 ft.  Water pressure coming out of hose is better than yard hydrant (house water system, submerged well ... about 12 gal/minute for house system?), but I can't speak for what kind of pressure would be maintained through sprinkler heads.  Hope this may be of some use....