Very Low Flow out of Return Jets

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R

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May 7, 2022
16
Ohio
Hello,

I purchased a home with this pool last fall and have been attempting to open it this week, so I'm still learning the system and don't know if this all might be normal or if something really is wrong.

When I first turned on the pump, the flow was very strong and shot out of both return jets well. After running the pump for the first 24 hours, the flow became really bad. At first I thought this would be because the cartridge became dirty (the pool does have some algae/contaminants currently). But after rinsing out the cartridge the flow did not change.
Another thing I noticed along with this low flow is that there are now air bubbles coming into the pump basket, with a little bit of it collecting at the top. This was not the case when it first turned on. These bubbles are also not coming out of the return jets, they appear to only exist in the pump basket. The pump is also taking longer to prime.

The flow currently feels like next to nothing. On one return jet, you can feel a little bit of flow if you press your hand right against it. On the second return jet, you can't feel really anything.

The filter cartridge pressure appears to be normal. It reads about 20psi after the filter is cleaned, and creeps up to 25-30psi as the filter gets dirty.

Here are the things I've looked at/tried:
Cleaned out the skimmer basket, pump basket, pump impeller, and filter cartridge
Pump lid o ring appears good and I added lubricant
I used a hose bladder to unblock anything that might have been in the skimmer line. Didn't see any major blockage come out
I used dish soap to check for leaks on the suction side and couldn't find anything
Checked the pump drain plug and used plumbers tape on it as well


Any suggestions as to what might be happening here would be much appreciated!
 
Welcome to TFP! :wave: Air bubbles are generally a sign of a suction side air leak (air getting IN), and you've done a good job checking the preliminary items. So here are some others to be safe:
1 - Pool water level high enough?
2 - Skimmer weir door/flap operating good?
3 - Any 3-way valves before the pump?

This may/may not be related to the reduced water flow, so we may have to take it one thing at a time.

By the way, at some point we're going to probably ask for water test results as poor chemistry can throw us off the scent. Do you have a TF-100 or Taylor K-2006C that we can see results from?

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Texas Splash,

Thanks for the reply.

Pool level I believe is okay - it's about halfway up the skimmer. Doesn't appear to be sucking in any air through the skimmer
This system does not have a weir
This system does not have any 3-way valves


As for chemistry, I do have a poolmaster 5 way test kit. I know these parameters are not in line with what they should be as I was still in the middle of balancing before this pump problem came up:
FC - 1-2ppm
Alkalinity - 40-50ppm
pH - 7.6
Hardness (tested via a test strip): 50-100ppm
CYA (don't have a great way to test this yet, but I added enough CYA to be at 30-40ppm)
 
Red,

All your problems point to a dirty filter...

I know you said you cleaned it, but I doubt it is clean enough.

There is really nothing else in the loop.. If I understand you correctly, there is just one pipe coming into the pump and one pipe leaving the filter and going back to the pool.

Single speed pump tend to work or not work, they do not run slowly or weakly.

It could be that your filter cartridge is just coated with something that you can't just hose off.

One thing that you could do is remove the cartridge and run the pump and see what your filter pressure and flow is.

Algae can fill up a small cartridge filter in a very short time.

Thanks,

Jim R.
 
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Jim,

I think you are right..it's so obvious I didn't even think about it

I ran it with no cartridge and it ran strong, and I didn't see any bubbles in the pump basket. The pump was making a rock-grinding noise which I remember reading can happen if the pump runs with too little resistance it can cavitate and create that noise

The cartridge pressure reading was all the way down while running with no filter

I suppose I need to work on my filter cleaning skills? Any suggestions there?
 
Just read through the cartridge cleaning guide. It says if the cartridge is covered in algae to do a dip with muriatic acid (1:20 ratio). Would you recommend starting there? Or starting with a commercial cleaner?
 
Red,

The first thing you would do is clean the cartridge off with just a hose and water.

Then you can soak it in cleaner or dishwasher soap. Hose it all off as best you can..

Then once as clean as you can get it, soak it in weak MA and hose it off again.

Not sure how old the cartridge is, but it might make sense to buy a new one, then you will have two that you can swap in and out.

Thanks,

Jim R.
 
This might surprise you, but I've had algae just like the rest. Especially when I first came to TFP. Never did an acid wash related to algae. Follow the SLAM Process first by using a proper test kit to get the chemistry right and a simple nozzle wash will do just fine to rinse out the dead algae. Remember, algae is not a mechanical problem, it's chemistry and keeping the FC-CYA ratio correct as noted on the FC/CYA Levels.
 
Hello,

I was able to get a brand new cartridge and put it in. I have a few follow up questions on some new things I'm seeing with this cartridge:

The pump is now making a minor rock grinding sound. I cleaned out the pump basket and felt around for debris in the impeller but couldn't find anything. I'm thinking possible cavitation? Should I be concerned here?

The pressure gauge on the filter is now reading very low, about 2psi with the new cartridge. It was reading 25psi with the dirty cartridge. Is this possibly a bad gauge?

Thanks!
 

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Gauge could be bad. Not uncommon if it was left out over winter. Now might be a good time to post a few pics so we can see your pool, the skimmer area, and perhaps a couple pics of the equipment pad. I think we need some better visuals to try and understand what might be happening.
 
After taking another close look at the skimmer, I believe it may actually be sucking in air. There's a pretty decent vortex that is forming in the skimmer and I can see a trail of bubbles in the vortex going down to the hole

My water line is pretty high, at least at half if not more of the skimmer opening. Perhaps I need a weir?
 
Last edited:
To give an update for anyone who references this in the future, I put a second skimmer basket on top of the first skimmer basket simply to stop the vortex and the pump noise has gone away. The filter pressure has also risen to about 7psi

I will buy a weir to hopefully regulate flow into the skimmer
 
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