LOW PRESSURE - TFP Forum Helped Me Narrow the Problem - Need Help Bringing it Home

[seanadamsinc]

First, I've been reading the forum for the past few days and it has been great to narrow our problems down.

The issue we are having in our inground pool is that our pressure has been very low (5psi).

After taking to this forum, I raised the water level, ensured that the skimmer baskets and impeller were clear, replaced the skimmer gasket, replaced the o ring in the pressure gauge but still no luck - sitting at 5 PSI with barely any water coming back into the pool.

This morning I came across a post that suggested running the pump with the filter removed. I had not heard of this so we gave it a try and bam - great pressure coming out of the jets!

My question is - is this normal to see increased pressure with no filters OR do I have a filter issue? The cartridge filters (we have 2 - a larger one and a small one that fits in the middle of the large one) are "clean" but the small filter is old - 5 years but the large filter is only a year old. My wife did use a brush to scrub the filter which we learned was a no no perhaps that has something to do with it.

Anyway, would appreciate any thoughts on what to do next. I'm thinking we have narrowed it to the filter but want to check if its normal to get an increase in pressure with filters removed.

Thanks!

 

[Pool Tool]

With your filters "removed" or at least bypassed are you really seeing increased pressure on the gauge? You are likely seeing increased flow from the jets, but not increased pressure. I am guessing your filter has the gauge on it so you are not able to see the pressure. I assume its even less than 5 psi since you are seeing the increased flow. E.g., pressure will build as flow reduces - that's why when you cover your garden hose with your finger it sprays further but mush less is coming out. It is typical to see lees flow, but higher pressure because the filter is nothing but a large restriction to the water. That's why we typically say to backwash a sand filter after a 20-25% increase in pressure or noticeably reduced flow from the jets.

Please explain your 2 filter set up? Is is actually two separate filters or just different filter elements in the same filter?

Folks on here with 2 speed motors report a pressure of zero on the gauge while running in low speed, but yet still have sufficient flow out of the returns.

 

[VikingPoolMan]

Where is the pressure gauge located (on your filter or some other location)? After you removed the filter, you said you got "great pressure out of the jets"? Do you mean "great flow" or was the actually pressure gauge reading a higher psi? Is so, what was the psi after you removed the filter? *Normally, if you run the system without a filter, the "flow" increases but the pressure (psi) typically goes down. Usually with a bad/clogged filter, your pressure increases.

*just saw above comment 'after' I wrote the above - basically the same thought.

First, I've been reading the forum for the past few days and it has been great to narrow our problems down.

The issue we are having in our inground pool is that our pressure has been very low (5psi).

After taking to this forum, I raised the water level, ensured that the skimmer baskets and impeller were clear, replaced the skimmer gasket, replaced the o ring in the pressure gauge but still no luck - sitting at 5 PSI with barely any water coming back into the pool.

This morning I came across a post that suggested running the pump with the filter removed. I had not heard of this so we gave it a try and bam - great pressure coming out of the jets!

My question is - is this normal to see increased pressure with no filters OR do I have a filter issue? The cartridge filters (we have 2 - a larger one and a small one that fits in the middle of the large one) are "clean" but the small filter is old - 5 years but the large filter is only a year old. My wife did use a brush to scrub the filter which we learned was a no no perhaps that has something to do with it.

Anyway, would appreciate any thoughts on what to do next. I'm thinking we have narrowed it to the filter but want to check if its normal to get an increase in pressure with filters removed.

Thanks!

 

[Divin Dave]

Sounds to me like it's a flow/ cartridge problem. Maybe a gauge problem too.

PSI on an open system such as a pool is actually opposite of psi in a closed system, such as in house plumbing where higher psi means higher velocity of water flowing in the pipes.

A low psi is indicative of a clear filter and good flow and there are no obstructions causing the psi rise- depending of course how large the filter is.

High pressure means the filter is more dirty and needs cleaning = lower flow . As the filter gets dirty, it causes backpressure and the pressure gauge will rise. If there was no/ low flow coming from the returns, and the flow increased because the cartridges were removed, then the cartridges are not letting the water pass through. Clean or replace the cartridges.

 

[seanadamsinc]

Thank you for the response. There is virtually no pressure reading on the gauge with the filters removed. I should have said - the jets are shooting harder but the gauge is still reading low.


Filters - we have 2 separate cartridge filters.


Thanks - any thoughts on what i should do next?

With your filters "removed" or at least bypassed are you really seeing increased pressure on the gauge? You are likely seeing increased flow from the jets, but not increased pressure. I am guessing your filter has the gauge on it so you are not able to see the pressure. I assume its even less than 5 psi since you are seeing the increased flow. E.g., pressure will build as flow reduces - that's why when you cover your garden hose with your finger it sprays further but mush less is coming out. It is typical to see lees flow, but higher pressure because the filter is nothing but a large restriction to the water. That's why we typically say to backwash a sand filter after a 20-25% increase in pressure or noticeably reduced flow from the jets.

Please explain your 2 filter set up? Is is actually two separate filters or just different filter elements in the same filter?

Folks on here with 2 speed motors report a pressure of zero on the gauge while running in low speed, but yet still have sufficient flow out of the returns.

- - - Updated - - -

Thank you for the response. There is virtually no pressure reading on the gauge with the filters removed. I should have said - the jets are shooting harder but the gauge is still reading low.


Filters - we have 2 separate cartridge filters.


Thanks - any thoughts on what i should do next?

With your filters "removed" or at least bypassed are you really seeing increased pressure on the gauge? You are likely seeing increased flow from the jets, but not increased pressure. I am guessing your filter has the gauge on it so you are not able to see the pressure. I assume its even less than 5 psi since you are seeing the increased flow. E.g., pressure will build as flow reduces - that's why when you cover your garden hose with your finger it sprays further but mush less is coming out. It is typical to see lees flow, but higher pressure because the filter is nothing but a large restriction to the water. That's why we typically say to backwash a sand filter after a 20-25% increase in pressure or noticeably reduced flow from the jets.

Please explain your 2 filter set up? Is is actually two separate filters or just different filter elements in the same filter?

Folks on here with 2 speed motors report a pressure of zero on the gauge while running in low speed, but yet still have sufficient flow out of the returns.

- - - Updated - - -

Thank you for the response. THe pressure gauge is located above the filter housing.
You are correct - I should have said "great flow" because the psi remained virtually nothing.

Any ideas on what to do next?

Thank you!

 

[Pool Tool]

Remove one of the cartridge filters? Any reason why there is two? One should be sufficient to filter water. Or pipe them in parallel to use one while you clean/maintain the other, but with them in series there are giving too much restriction for your pump.

 

[VikingPoolMan]

Remove one of the cartridge filters? Any reason why there is two? One should be sufficient to filter water. Or pipe them in parallel to use one while you clean/maintain the other, but with them in series there are giving too much restriction for your pump.

I've seen some cartridge filters that have two elements inside (one small one large)... it's the way it's designed. However, maybe he is saying he has two completely separate filters... if that's the case, I agree one should be sufficient.

 

[seanadamsinc]

I'm better at reading then explaining - sorry about this. VikingPoolMan is right - the cartridge filter has two elements - one small and one large - the way its designed.

- - - Updated - - -

I'm better at reading then explaining - sorry about this. VikingPoolMan is right - the cartridge filter has two elements - one small and one large - the way its designed.

 

[Divin Dave]

Your pressure reacted exactly as it should have. Higher with filters in and lower with filters out.
Your filters are simply dirty. All you need to do is clean them.

As the filters get dirtier, the pressure will rise.
As the filters are cleaned, the pressure will fall.

TFP recommends cleaning the filter when the pressure rises by 20-25% above "clean" pressure.

 

[seanadamsinc]

I think I did a poor job of explaining - my apologies. Better stated -
The PRESSURE ON THE GAUGE with the filters IN is 5 psi
The PRESSURE ON THE GAUGE withe the filters OUT is non-existent.

The WATER FLOW out of the Jets when the filters are IN is weak to non-existent.
The WATER FLOW out of the Jets when the filters are OUT is strong.

I'm soaking the filter now and will try it in the morning.
I'm just trying to get a step ahead to see if anyone has experience with something like this and can help point me in the right direction if cleaning the filter is not enough and I have indications of something else.

Thank you all.

Your pressure reacted exactly as it should have. Higher with filters in and lower with filters out.
Your filters are simply dirty. All you need to do is clean them.

As the filters get dirtier, the pressure will rise.
As the filters are cleaned, the pressure will fall.

TFP recommends cleaning the filter when the pressure rises by 20-25% above "clean" pressure.