Hello and Thank You

TimothyS

New member
Feb 26, 2017
3
Florida
#1
Hello All,

Like many others, I've recently purchased a new home that came with a swimming pool. Also, like many, I have never owned or maintained a pool, so this is a completely new and hopefully great experience that I am about to embark on! I noticed that every time I did a search on Google, the result I was looking for seemed to point me back to this site. So even before being a member, many of you have already been a big help - so thank you!

Being that I am a total novice, I have a guy from the local pool store coming by today to show me the basics of how my equipment works and the proper way to use the valves in order to run the vacuum and do the backwash. While I did manage to watch the previous owner perform a backwash in December, I really didn't understand the entire process as I couldn't relate the actions to the reason why they were being done. Thankfully, the pool guy will be just in time as it seems that the filter pressure has been running a bit high over the past week. I suspect it is time for another flushing, but there is something else that is giving me pause.

When the filter starts up in the morning (8am) it runs high. However, I noticed that around 11am the pressure drops back down to the normal range? I don't quite understand why this may be happening? It doesn't appear that the pump is losing prime as I do not see any bubbles in the pump window. Also, I would think that if the pump were to be losing prime, it would do so shortly after having started (e.g., 5 mins), not 3 hours later. I'll definitely be sure to ask the pool guy, but was hoping I could get some feedback from the folks here, too, in case the pool guy doesn't have a compelling answer.

As for the other details, that I believe are relevant, the pool water is very clear and there doesn't seem to be any major issues going on. I have been working to get the chemistry balanced as the pH is a bit high and the calcium hardness is a bit low. I also need to go ahead and order the Taylor K-2006 or TF-100 test kit (just trying to decide which one to get) so I can stop having to take my water samples in every week. Otherwise, I think I'm okay for the moment, but will have to step up my game as the weather warms.

Anyhow, thanks again for all the help thus far and for what I'm sure will be additional help in the coming days/months/year!
 

santacruzpool

Gold Supporter
Feb 24, 2015
522
Santa Cruz, CA
#2
You list a VS pump - I would check to see if your pump speed is changing at 11AM - if the pump speed is different (lower at 11AM than 8AM), then that could explain the pressure drop.
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
10,488
Bedford, TX
#3
Tim,

Welcome to TFP... A Great resource for all your pool questions... :testkit:

The filter pressure is actually the amount of effort it takes to push water through the filter. As santacruzpool says, the most likely cause for a pressure change is the pump is running at a different speed.

As an example.. When I run my pump at 1,200 RPM my filter pressure is only about 2 or 3 psi. When the pump runs at 2,000 RPM, the filter pressure is about 8 psi.

It is important to know what the filter pressure is when the filter is "clean". Since you have a variable speed pump, it is also important to always check this pressure at the same pump speed. I would recommend using 2,500 RPM, or somewhere in the range. Once you know the "clean" pressure (and speed), you need to backwash or clean the filter, whenever the pressure increase about 25% over your clean reference point.

Backwashing is just part of owning a DE filter. You can only backwash, a few times before you have to disassemble, clean the grids, and reassemble the filter. It would be great if the pool guy could show you that operation while he is there.

I never backwash my DE filters... I just disassemble and clean them about twice a year. Usually in the Spring and then again in the Fall...

Thanks for posting,

Jim R.
 

TimothyS

New member
Feb 26, 2017
3
Florida
#4
Finished meeting with the pool guy and feel much better about the tackling the pool maintenance myself. You both were correct, the pump was set to run at 3200 RPM when it started in the morning and then at 11am a second timer switched to a lower RPM. The higher RPM increases the pressure at the filter, which put it just under inside the RED range on my gauge (18 PSI). Once the pump kicked over to the lower RPM (2500 RPM) at 11am, it was running well within the normal range that I recall seeing it at when I visited and watched the previous owner (10 PSI). Now that I am thinking about it again, I'm curious why would I want the pump to run at different speeds during the day? Is there a benefit to this?
 

triptyx

TFP Guide
Apr 12, 2016
1,485
Tucson, AZ
#5
The main benefit is energy savings. You can circulate the pool to keep the chemicals distributed and balanced for a good part of the day, then kick into a higher speed for shorter periods to get the vacuum running, the skimmer skimming, etc. The pump can circulate the water adequately at low speed to save energy, and you save the higher energy usage for actively cleaning up debris.
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
10,488
Bedford, TX
#6
Tim,

The whole purpose of having a VS pump is to save money on your electrical bill. Running your pump at high RPMs takes away from the reason of having a VS pump.


You generally run a pump for three reasons:

1. To keep surface debris moving and being pushed into the skimmers. The more debris the more often you need to run the pump.

2. If you have a Salt Water Chlorine Generator (SWCG) you'll need to run it long enough to generate the amount of chlorine needed.

3. To circulate the water to ensure the chlorine is effectively distributed throughout the pool. Two or three hours per day is all that is needed for this to happen in most pools.


I suggest that you see how low of an RPM that you can run and still make your SWCG's flow switch close. (Some where between 900 and 1200 RPM). This is the speed that you should run most of the time that it takes to make the amount of chlorine you need.

Then I suggest you increase the speed to 1800 to 2200 for a couple of hours a day to keep the skimmers working.

But each pool is a little different, just play with it to get it to where you are running your pump as slow as possible for the shortest period of time that allows you to accomplish the items listed above.

Thanks,

Jim R.
 

TimothyS

New member
Feb 26, 2017
3
Florida
#7
The main benefit is energy savings. You can circulate the pool to keep the chemicals distributed and balanced for a good part of the day, then kick into a higher speed for shorter periods to get the vacuum running, the skimmer skimming, etc. The pump can circulate the water adequately at low speed to save energy, and you save the higher energy usage for actively cleaning up debris.
Tim,

The whole purpose of having a VS pump is to save money on your electrical bill. Running your pump at high RPMs takes away from the reason of having a VS pump.


You generally run a pump for three reasons:

1. To keep surface debris moving and being pushed into the skimmers. The more debris the more often you need to run the pump.

2. If you have a Salt Water Chlorine Generator (SWCG) you'll need to run it long enough to generate the amount of chlorine needed.

3. To circulate the water to ensure the chlorine is effectively distributed throughout the pool. Two or three hours per day is all that is needed for this to happen in most pools.


I suggest that you see how low of an RPM that you can run and still make your SWCG's flow switch close. (Some where between 900 and 1200 RPM). This is the speed that you should run most of the time that it takes to make the amount of chlorine you need.

Then I suggest you increase the speed to 1800 to 2200 for a couple of hours a day to keep the skimmers working.

But each pool is a little different, just play with it to get it to where you are running your pump as slow as possible for the shortest period of time that allows you to accomplish the items listed above.

Thanks,

Jim R.
Thanks for the information, this is helpful. It sounds like I can potentially run the pump at a lower RPM than it is currently set at, which would be great! At 3200 RPMs, the noise carries into the adjacent room and is noticeable. This does not occur at 2250 RPMs.

So how do I know if I have the pump running fast enough to still make the SWCG's flow switch close? Is that simply ensuring the light on the Aqua Rite that indicates "No flow" is not lit or that the light indicating "Generating" is solid?
 

Mavrk

Active member
May 24, 2013
30
Central/East FL
#8
Thanks for the information, this is helpful. It sounds like I can potentially run the pump at a lower RPM than it is currently set at, which would be great! At 3200 RPMs, the noise carries into the adjacent room and is noticeable. This does not occur at 2250 RPMs.

So how do I know if I have the pump running fast enough to still make the SWCG's flow switch close? Is that simply ensuring the light on the Aqua Rite that indicates "No flow" is not lit or that the light indicating "Generating" is solid?
Yes, just change it until the flow light turns on (or off if going slower). Then bump it up one level higher than that for the times you want your SWG to be in use. The reason to go one higher is to ensure the pressure will be enough as the filter gets dirty and the psi goes down. Also, it is good to have a small buffer to make sure it will always work.