Pump pressure question/troubleshooting

[Buzzaro]

Hey Guys,
So I posted a few weeks ago about choosing a submersible pump for an irrigation system that will pull from a creek. I got it set up and running and it worked great at first. Now though it won't maintain the same pressure as when it first got going. I've got a CSV125-3 on there at 50psi. So here's all the stats and what's going on.
When I first got it running it would maintain 50psi with a hose bibb wide open and was doing roughly 30gpm (crude bucket test) that's only with 10 feet of elevation from water to spigot
Now after a couple weeks of use, it only maintains around 40psi with the spigot at around 1/4 turn. Other than that it seems to be working ok.
Any ideas on what's going on?
Thanks
Hallmark 1hp 33gpm submersible (yeah I went with the cheap one to make sure my set up was even going to work)
Cycle Stop Valve 125-3 on the drop pipe (all threaded connections prior to the valve)
Rain Bird disc filter
20 gal pressure tank at 38psi
pressure switch set to 40-60

 

[Reach4]

Rain Bird disc filter

Clean the filter?

 

[Sponsor]

 

[Buzzaro]

Clean the filter?

I did open it up and take a look. It didn't appear to be that bad but I don't have the experience to know what a full disc filter element looks like. I'll pull it out today, actually clean it, and see if that makes any difference.

 

[Valveman]

pull from a creek.

If you don't have a good inlet strainer of some kind I would guess the pump screen and/or the eye of the first impeller are clogged.

 

[Buzzaro]

If you don't have a good inlet strainer of some kind I would guess the pump screen and/or the eye of the first impeller are clogged.

What kind of strainer should I have on there?
Currently I've got a screen that's about 1/4" that keeps sticks and leaves out of the 6" pipe, then it's got the 4" induction pipe around the motor, then it's got the stock screen on the intake of the pump itself. The pipe is also turned up at the bottom of the creek so it's not sucking from the creek bed but from the water flowing above.

 

[Buzzaro]

I pulled the pump to see if appeared to be clogged. To me it doesn’t but maybe I didn’t dig far enough into it? Anyway here’s a couple pics of the screen on the pump and the best I could get of the first stage intake.

 

[Valveman]

Good pics. Doesn't look clogged. Those pumps don't build much pressure. Make sure your filters are clean.

 

[Buzzaro]

Good pics. Doesn't look clogged. Those pumps don't build much pressure. Make sure your filters are clean.

Cool thanks. I did rinse out the disc filter, which really didn’t seem all that dirty, and it didn’t make a difference. I guess the pump just isn’t meeting it’s spec. It makes the claim of 207’ head, but it’s really only making around 120’ or so. 45 psi with one hose sprinkler and drops to 40 with two and 20-25’ of lift depending on where on the property I am. It’s not going to be enough to run my sprinklers without planning itty-bitty tiny zones. I’m going to go ahead and pull the pump and replace it with a Goulds 25GS10
Thanks again for the help

 

[Valveman]

Not much difference in a 25 and a 33 GPM pump. The Hallmark was doing it and something changed. What is holding the pump up? It doesn't look like the pipe is sitting on the well seal? Is the pump just sitting on the bottom of the well?

 

[Buzzaro]

Not much difference in a 25 and a 33 GPM pump. The Hallmark was doing it and something changed. What is holding the pump up? It doesn't look like the pipe is sitting on the well seal? Is the pump just sitting on the bottom of the well?

The pump is in the 6” PVC with a torque arrestor just above the pipe connection to the pump that holds it roughly centered. Then the 6” PVC is laying at about a 45 going into the creek. The discharge then comes out of the well seal, which is really just there to hold the discharge pipe and conduit, doesn’t really do any sealing. Other than possible clogging I can’t really think of anything that’s changed. The pump looked the same when I pulled it and if it moved it couldn’t have been more than 1” or so. I’ve got an inducer on it and the water comes from below the pump. It’s has a few days of pretty heavy use, supplying concrete trucks and running sprinklers for 8+ hours. That’s about all I can think of.

 

[Valveman]

An extra 10' of lift makes a big difference with that pump?

 

[Buzzaro]

An extra 10' of lift makes a big difference with that pump?

I'm not sure what you mean, the pump hasn't moved. I do know that whether I'm running a sprinkler though a hose at an area with only around 10-15' of total lift vs running a sprinkler through a hose at an area with 20-25' of total lift (from the surface of the creek) the results are roughly the same. Holds 40-45 psi (I've got a 50psi CSV on the line before the pressure switch/tank) with the water on. Is that what you mean?

 

[Valveman]

I am talking about lift from the river. If the water level in your casing drops 10' or so it will make a lot of difference. Like if your screen is clogging up and the water in the casing is 10' lower than the river level.

That pump can build 89 PSI max. That is something you could check before replacing the pump.

 

[Buzzaro]

I am talking about lift from the river. If the water level in your casing drops 10' or so it will make a lot of difference. Like if your screen is clogging up and the water in the casing is 10' lower than the river level.

That pump can build 89 PSI max. That is something you could check before replacing the pump.

Oh ok, got it. No the water level doesn't change. It's only in around 30" of water and doesn't fluctuate, it will come up a foot or two in the winter but it's about as low as it gets. I'll remove the blowoff and see if it builds over 85.

 

[Valveman]

I'll remove the blowoff and see if it builds over 85.

Where is the blow off?

 

[Reach4]

Where is the blow off?

He is referring to the pressure relief that is next to the pressure switch.

Buzzaro, I would temporarily increase the air precharge to maybe 70 or 80 first. I don't know if your pressure tank has an internal dome to prevent overstretching the diaphragm, but increasing the precharge with the power off won't hurt. Then deadhead the pump for your test, and turn the power back off. Then release the water pressure and restore precharge.