I finished the pool in May 2010. After the plaster dust settled and the water cleared up I cleaned the filter even though the pressure had really never changed. I think it may be due to the size of the filter relative to the size of the pool. It didn't look bad considering how much plaster I sucked up with the vacuum. It's a 450 sq. ft. cartridge filter and the pool is about 15,000 gallons. Since the beginning of last May (almost 11 months now) the pressure has only gone from 15 psi to 17 psi. I've heard the rule of thumb is to clean the filter after it rises 10 psi. At this rate, that will never happen. Is there a time frame that you should clean it out at if the pressure doesnt change?
When to clean my filter if pressure does not rise
- Thread starter n8huntsman
- Start date
A number of people on the forum talk about cleaning their carts once a year, need it or not. Brag, brag...
--paulr
--paulr
Not really. Over sized filters are great for just that reason, long stretches between cleanings. As long as you don't suspect a problem with the pressure gauge you can let it run until you reach that 10 pt rise. If you winterize the pool you would clean the cartridge before storing it for the winter, that would give you an annual cleaning. Enjoy your pool, it sounds great!
- May 3, 2007
- 16,832
- Pool Size
- 20000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
I have the same situation and I think is a good thing. Waiting for a pressure rise of 10 PSI is a huge waste of energy. That is an extra 23' of head and will result in a large decrease in flow rate. I wouldn't go past 2 PSI rise but I am very sensitive to head loss.
Anyway, I will usually clean my filter once or twice a year and rarely see a pressure rise. This year I was lazy so I am waiting until the beginning of warm weather at which point I will clean the filter. I hate cleaning the filter when cold out. So my advice is clean the filter when it is convenient and at least once a year but don't let the PSI rise too much.
Anyway, I will usually clean my filter once or twice a year and rarely see a pressure rise. This year I was lazy so I am waiting until the beginning of warm weather at which point I will clean the filter. I hate cleaning the filter when cold out. So my advice is clean the filter when it is convenient and at least once a year but don't let the PSI rise too much.
If I wanted to soak this monster cartridge in TSP, how would I go about it? It's too big to put in anything. Can I close the valves and soak it in the filter housing? Then drain the housing once it's done soaking?
- May 3, 2007
- 16,832
- Pool Size
- 20000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
I use a large plastic garbage can but normally, I don't bother soaking the cartridge unless there is a lot of suntan oil embedded in the media.
Hmmm. There's an idea. So now now only do I have to clean my filter, buy I also need to clean my garbage can. This is going to be an all day project I think. How will I know if there is suntan oil embedded? Can you actually see it?
You might see a scum line around the pool if your household uses a lot of sunscreen. I don't think you would be able to feel it unless it was really bad, and then you would probably had the pressure rise to go with it. I would get a nice big new garbage can and use it only for filter soaking.
Back to the 10 psi rule of thumb, if we could.
I've been doing some energy calculations for our soon-to-be pool, and I found Jandy and Pentair both suggest cleaning at a 10 psi rise. I put this number into our pump curve, and 10 psi would bring our flow to a halt. I checked a couple other common pump curves and in all cases it would result in a huge reduction of flow. Am I missing something? Or are the filter manufacturers using this number because it makes their product look low maintenance, even though it is not at all practical?
I've been doing some energy calculations for our soon-to-be pool, and I found Jandy and Pentair both suggest cleaning at a 10 psi rise. I put this number into our pump curve, and 10 psi would bring our flow to a halt. I checked a couple other common pump curves and in all cases it would result in a huge reduction of flow. Am I missing something? Or are the filter manufacturers using this number because it makes their product look low maintenance, even though it is not at all practical?
- May 3, 2007
- 16,832
- Pool Size
- 20000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
Exactly, you are not missing a thing. 
I would never wait 10, 5 nor even a 3 PSI rise. It just doesn't make sense for both energy conservation and keeping the pool clean. Having such a drastic reduction in flow rates would increase turnover time and cause problems in water clarity. However, if I had to clean the filter every week, that would be a different story and I would probably deal with higher PSI rise. As long as you oversize the filter, a 1-2 PSI rise or even less is high enough.
I would never wait 10, 5 nor even a 3 PSI rise. It just doesn't make sense for both energy conservation and keeping the pool clean. Having such a drastic reduction in flow rates would increase turnover time and cause problems in water clarity. However, if I had to clean the filter every week, that would be a different story and I would probably deal with higher PSI rise. As long as you oversize the filter, a 1-2 PSI rise or even less is high enough.
Hijacking just a little......mas985, I have never been fond of the 10psi rise either.....mostly because my normal psi is 9 to begin with.
Do you think it would make more sense to suggest a percentage rise? So, if your normal psi was 20 and the suggested rule of thumb to backwash was 25%, you would generally be ready to backwash around 25psi. If your normal psi was 10, you would backwash somewhere around 12.5
Do you think it would make more sense to suggest a percentage rise? So, if your normal psi was 20 and the suggested rule of thumb to backwash was 25%, you would generally be ready to backwash around 25psi. If your normal psi was 10, you would backwash somewhere around 12.5
I usually stick to about 10 psi with my sand filter. It seems that sand filters will actually filter the water better after they are slightly loaded with dirt. With the 2-speed pump, my clean filter pressure is less than .5 psi, and I will backwash when it rises to about 3-4 psi. This usually comes out to be a 8-10 psi rise when in high speed.Johnny B said:
Being inherently lazy, I only clean my filter when the return flow gets low. That usually coincides with an 8-10 pt rise. When I am a good girl and stay on top of my water chemistry it can take a long time to get to that state.
I find that I clean mine when it needs it. If I'm going from swamp to clean, like I'm doing now, I'm likely to clean my filter every week or so. My pressure is only up 5psi over where it started but I just know that the filters have to be filthy considering how much cleaner the pool looks than where ti was a week ago. Thus, I clean it todya.
That said, if the pool stays clear, I'll probably only wash every couple of months as long as the pressure stays low.
That said, if the pool stays clear, I'll probably only wash every couple of months as long as the pressure stays low.
- May 3, 2007
- 16,832
- Pool Size
- 20000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
duraleigh said:
Yes, I think a precentage rise is a better metric to use although I would probably set the target a bit lower and use 25% as a maximum. If the filter is large enough, even cleaning at 10% shouldn't be a burden. But for people with smallish filters, as pointed out by some, even 25% could be cleaning the filter quite often.
So my advice to anyone is to clean your filter often enough so as to avoid a substantial PSI rise but not so often that you feel it is a burden.