Bottom returns don’t have the same pressure?

Yaeugd

Well-known member
Aug 15, 2017
77
Long Island, NY
I have a newer pool without a main drain instead I have bottom returns to help circulate air. This season I noticed that the pressure coming out of them is less. This is concerning because it usually helps circulate the warm water when the Heater is on. I noticed it also when I cleaning the pool manually I used to have bubbles coming out of them as a gas exchange when the pressure was good. I don’t believe I have a leak because I have not added water since i opened it up and the level looks constant. First I thought the de filter was dirty even though the pressure was fine. I cleaned it off anyway and the flow still low or not as strong. I don’t have anything dripping at the pump or equipment ever since I changed the o-ring on Knuckle couplng on the multiport union. I wonder if there is something stuck in the pipe impeding the flow? I wouldn’t even know how to check for it because my equipment is downhill I would just water back flow into me.
I posted the pics when the pool was getting built since you can see them better
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
23,596
San Dimas, CA (LA County)
Was your water cloudy when you started? You might have a clogged filter.That will reduce the flow a good deal. DE filters don't last long against dirty water. They filter too good sometimes. Have you been monitoring your filter pressure?
 

Yaeugd

Well-known member
Aug 15, 2017
77
Long Island, NY
My pressure is fine it’s a little more than. 10 psi. I cleaned out the filter By backwashing it the 3 days ago and it Did not fix it. Wouldn’t dirty filter Grids effect my pressure and Increase my psi pressure?
I had a slightly green pool when I opened it. Resolved it in 24 hours. Now it’s very a clear pool just lower jet pressure Especially on the bottom returns
 
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Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
23,596
San Dimas, CA (LA County)
Low pressure might mean restricted intake. Ensure all the winterizing plugs are out, all the valves are open, and all the baskets are clean. Question: do you have any pine trees around? Because pine needles can slip past the baskets and get lodged in the impeller and reduce flow.
 

Yaeugd

Well-known member
Aug 15, 2017
77
Long Island, NY
All plugs are out and skimmers are constantly clear. I do t have any pine tree near the pool but there’s one in the back of the property but doubt it’s contributing to the issue. The pool would be cloudy if it wasn’t circulating well? I wonder could I have clogged filter grids but wouldn’t that increase my psi on the filter?
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
23,596
San Dimas, CA (LA County)
All plugs are out and skimmers are constantly clear. I do t have any pine tree near the pool but there’s one in the back of the property but doubt it’s contributing to the issue. The pool would be cloudy if it wasn’t circulating well? I wonder could I have clogged filter grids but wouldn’t that increase my psi on the filter?
But have you fished any needles out? Pine needles in the impeller won't slow it down, but it won't move as much water. Go tape across some fan blades and see how hard it blows. But I'm out of ideas.
 

Yaeugd

Well-known member
Aug 15, 2017
77
Long Island, NY
I don’t understand (go tape some fan blades). I have a variable speed pump and the Impeller is in the pump body. Should I just take the pump apart? Or there is a easier way
 

mas985

TFP Expert
LifeTime Supporter
May 3, 2007
13,490
Pleasanton, CA
I have a newer pool without a main drain instead I have bottom returns to help circulate air. This season I noticed that the pressure coming out of them is less.
How do you know the pressure is less out of the bottom returns? How are you measuring pressure?

My pressure is fine it’s a little more than. 10 psi.
If the filter pressure is normal, then it isn't a pump issue.
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
23,596
San Dimas, CA (LA County)
I don’t understand (go tape some fan blades). I have a variable speed pump and the Impeller is in the pump body. Should I just take the pump apart? Or there is a easier way
If you can't visualize why the pump would show full speed yet less water is moving, go find a fan and tape across the blades. It won't blow much if any despite spinning full speed. That's what happens if pine needles get caught in the impeller of your pool pump.
 

Yaeugd

Well-known member
Aug 15, 2017
77
Long Island, NY
How do you know the pressure is less out of the bottom returns? How are you measuring pressure?
Because when I clean the pool by vacuuming there is little or no bubbles from them. Before they was a good amount. Pump is working because able to vacuum The pool. Or when I would isolate them on the 3 way valves I would see more pressure blow from them from underneath
 
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mas985

TFP Expert
LifeTime Supporter
May 3, 2007
13,490
Pleasanton, CA
There shouldn't be any bubbles from the returns. If there are bubbles, then you have an air leak somewhere.

Did you only see the bubbles only when vacuuming but not other times? That is an indication of an air leak as the vacuum creates low pressure in the pump basket which makes it more likely for an air leak.
 

Yaeugd

Well-known member
Aug 15, 2017
77
Long Island, NY
You know what I had a ozonator operating before this year because I kept it off that usually produces bubbles from my jets I kept it off this year because it’s a money out of maintenance. Maybe that’s why I don’t see as much bubbles.