borjis
LifeTime Supporter
Filter is more sensitive after pump upgrade, needs more backwashing
- Thread starter pcm2a
- Start date
I took this cheap 14" brush that I bought from Walmart for when I put calcium hardness in. I brushed that down the sides of the pool and about 3 feet along the bottom and then back up the wall. All around the pool. Looks the same, clear. I've never brushed the pool before but I have used this brush right along the water's edge to get pollon off that sticks to the walls.
I may have found a piece to the puzzle. I have been keeping the FC above the recommended 5 for 7 days. Yesterday while enjoying the pool I had the pump running at 3100 rpm. Flow was perfect. I was done for the day and I reduced the speed down to 2500. Immediately the flow was reduced to less than what 2500 is. Next I turned the pump up to the max, 3450 rpm, and the flow was less than what it should be. I checked the PSI and it was at 22. 18-19 is the clean point. I turned the pump off for a few minutes, I was going to backwash it. Instead I turned the pump back on. 18 PSI, flow was normal!!! I ran it at a slower speed for the rest of the evening, had it off over night, then back on in the morning. Flow is looking good this morning, 3450 rpm PSI still at 18.
I was running my pump 24/7, at a slow speed at night. Now I will go back to leaving the pump off over night and see if in another week speeds reduce. Why would running the pump 24/7, and changing speeds throughout the day, cause the PSI to creep up?
5/23 9:00 pm, 5.0 FC (chlorine added)
5/23 11:30 pm, 9.0 FC
5/24 9:00 am, 8.0 FC
OCLT: 1.0 (The sun was up 2 hours ago, so it could be less than 1.0 if I had gotten to it earlier)
I was running my pump 24/7, at a slow speed at night. Now I will go back to leaving the pump off over night and see if in another week speeds reduce. Why would running the pump 24/7, and changing speeds throughout the day, cause the PSI to creep up?
5/23 9:00 pm, 5.0 FC (chlorine added)
5/23 11:30 pm, 9.0 FC
5/24 9:00 am, 8.0 FC
OCLT: 1.0 (The sun was up 2 hours ago, so it could be less than 1.0 if I had gotten to it earlier)
It has been almost a month and I wanted to report on my findings. My original question was why did this happen when I got a new variable speed pump. I am 100% sure why now, it is the pump running at slow speeds and gravity (someone can probably explain this better). My equipment is a little wacky, out from the pool pump there are 3 pipes that go down to the jets in the pool. Also water flows through my spa pump and into the spa which has to go up above the ground. The spa spills over in the pool.
From a PSI perspective, running at 2500 rpms is at 12-13 psi and it's been there since the last backwash over a month ago. Nice! Below is a list of various findings I have came up with from a month of testing.
Scenario 1:
Run pump at 3450 for 5 minutes, then reduce to 2500rpm. To keep the math easy, guess that 50% of the water flow is coming down the spillover and 50% of it is coming out the jets in the pool. The slower moving water wants to take the easiest path, down instead of up into the spa. Over the course of 12 hours the water flow at the spillover is now 40% and the water coming out of the jets is 60%. Over 24 hours the spillover is now at 20% and the pool jets are at 80%. Slowly the water is taking the easier path. Turn the pump off for one second, 3450 for 5 minutes then 2500 and you are back to 50/50.
Scenario 2: The pool cleaner
While running the pump at 2500 rpm with 50% spillover and 50% jets, run the pool cleaner for an hour. The pool cleaner has a booster pump. While the pool cleaner is running the flow at the spillover is greatly reduced, say down to 20%. Now turn the robot off and the spillover will not go back to 50%, I think it's easier for the water to go downhill. So now maybe it's 30% at the spillover and 70% at the pool jets. An alternative that works fine is to run the pump at 3100rpm or 3450rpm while the cleaner is running, then switch back to a lower speed after.
Scenario 3: Children in the spa
Running the pump at 2500 rpm, with 50/50 split of water flow, the kids get in the spa and splash around. The splashing around in the spa is disrupting the flow of water. They play in and out of the spa for hours and now the flow at spillover is 30% and the pool jets are at 70%. I found it interesting that them being in there could affect the flow.
Scenario 4: Slower speed to faster speed
Running the pump at 1750 rpm and the spillover is barely going, 5% at the spillover, 95% at the pool jets. Now increase the speed to 2500. The spillover is going to increase a little but not to 50/50.
For the past couple weeks I've been running 3450 for 30 minutes and then 2500 for 14 hours. Leave the pump off overnight. Is there any advantage to running the pump at a super slow speed, like 1400 rpm, overnight vs leaving it off?
From a PSI perspective, running at 2500 rpms is at 12-13 psi and it's been there since the last backwash over a month ago. Nice! Below is a list of various findings I have came up with from a month of testing.
Scenario 1:
Run pump at 3450 for 5 minutes, then reduce to 2500rpm. To keep the math easy, guess that 50% of the water flow is coming down the spillover and 50% of it is coming out the jets in the pool. The slower moving water wants to take the easiest path, down instead of up into the spa. Over the course of 12 hours the water flow at the spillover is now 40% and the water coming out of the jets is 60%. Over 24 hours the spillover is now at 20% and the pool jets are at 80%. Slowly the water is taking the easier path. Turn the pump off for one second, 3450 for 5 minutes then 2500 and you are back to 50/50.
Scenario 2: The pool cleaner
While running the pump at 2500 rpm with 50% spillover and 50% jets, run the pool cleaner for an hour. The pool cleaner has a booster pump. While the pool cleaner is running the flow at the spillover is greatly reduced, say down to 20%. Now turn the robot off and the spillover will not go back to 50%, I think it's easier for the water to go downhill. So now maybe it's 30% at the spillover and 70% at the pool jets. An alternative that works fine is to run the pump at 3100rpm or 3450rpm while the cleaner is running, then switch back to a lower speed after.
Scenario 3: Children in the spa
Running the pump at 2500 rpm, with 50/50 split of water flow, the kids get in the spa and splash around. The splashing around in the spa is disrupting the flow of water. They play in and out of the spa for hours and now the flow at spillover is 30% and the pool jets are at 70%. I found it interesting that them being in there could affect the flow.
Scenario 4: Slower speed to faster speed
Running the pump at 1750 rpm and the spillover is barely going, 5% at the spillover, 95% at the pool jets. Now increase the speed to 2500. The spillover is going to increase a little but not to 50/50.
For the past couple weeks I've been running 3450 for 30 minutes and then 2500 for 14 hours. Leave the pump off overnight. Is there any advantage to running the pump at a super slow speed, like 1400 rpm, overnight vs leaving it off?
Flying Tivo
TFP Guide
- Jan 24, 2017
- 2,939
- Pool Size
- 7500
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
This was your original question and what you are talking about is headloss, two diffrent things altogether.
At the start the symptoms were: (1) got new pump (2) flow at the spillover reduced (3) backwashing fixed. After a month of repairs (that weren't needed) and testing I found by random chance that turning the pump off also resolved everything. Prior to this I thought it was a backwash issue, how would I know different. So at that point I knew turning the pump off fixed things and past that point I started doing tests with the speeds. During all of this time no one mentioned headloss, which until now I had no idea about. I'll be doing some research on headloss to see what other people are doing.
Flying Tivo
TFP Guide
- Jan 24, 2017
- 2,939
- Pool Size
- 7500
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
I've found that I have to backwash more frequently with my VSP. My theory is the sand works better at filtering at a lower speed whereas the high speed blows more dirt through the filter. I think someone said this above as well. My water is also clearer, and I haven't had to add any filter "helper".
About the filter "helper". It took forever (weeks) for my pool to completely clear when I opened it in the spring. The chemicals were fine, but there was just a very slight haze to the water. The pool store suggested adding some synthetic DE to the filter via the skimmer and, in a few d ays, the slight haze was gone. Therefore, I think my filter wasn't working so good.
Replaced my single speed pump for a VSP, completed a sand deep clean and it clears up in a few days without the help of the DE. However, I do find myself backwashing more frequently. However, I see this as a good thing. I also think some of my kids friends pee in the pool.
About the filter "helper". It took forever (weeks) for my pool to completely clear when I opened it in the spring. The chemicals were fine, but there was just a very slight haze to the water. The pool store suggested adding some synthetic DE to the filter via the skimmer and, in a few d ays, the slight haze was gone. Therefore, I think my filter wasn't working so good.
Replaced my single speed pump for a VSP, completed a sand deep clean and it clears up in a few days without the help of the DE. However, I do find myself backwashing more frequently. However, I see this as a good thing. I also think some of my kids friends pee in the pool.
The latest set of tests that I'm performing is with the amount of water in the pool. This week the water was low enough that I was going to have to add some in. I noticed that the headloss was non-existant. So now I'm performing all the same tests with low speeds, keeping the water on the low side, about 2 inches above the basket. It's just a theory at this point, but for a couple days it seems like less water in the pool means less or no headloss when running at low speeds.
Quick update. I've done some tests with low speeds and the booster pump pool cleaner.
Pool full (meaning the water level is high at the skimmers): 2500 rpm, run cleaner, spillover has a very reduced flow. Stop cleaner, more flow at the jets, spillover does not recover.
Pool low (meaning there is about 1 inch of water above the skimmer): 2500 rpm, run cleaner, spillover reduced by 10%. Stop cleaner, spiller recovers.
I'm really liking how things are running with the water level on the low side. I'm going to move on soon to some tests at 2250 rpm.
Pool full (meaning the water level is high at the skimmers): 2500 rpm, run cleaner, spillover has a very reduced flow. Stop cleaner, more flow at the jets, spillover does not recover.
Pool low (meaning there is about 1 inch of water above the skimmer): 2500 rpm, run cleaner, spillover reduced by 10%. Stop cleaner, spiller recovers.
I'm really liking how things are running with the water level on the low side. I'm going to move on soon to some tests at 2250 rpm.