Hi i have a 100,000-140,000 gallon pool. It uses 3 sand filters and 3 pumps that are old like 20-30 years old. What size cartridge should i upgrade to? 
What size cartridge filter should i upgrade to?
- Thread starter Justingambini47
- Start date
Hi i have a 100,000-140,000 gallon pool. It uses 3 sand filters and 3 pumps that are old like 20-30 years old. What size cartridge should i upgrade to? 
- Feb 6, 2015
- 6,245
- Pool Size
- 12300
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
With a pool volume of 100k to 140k gallons, you will probably need the same number of cartridge filters as you have sand filters - or you will have to look into a commercial sized filter system. The largest cartridge filters for residential pools are in the 500 sq. ft. range.
Tell us a bit more about this pool and its equipment.
Tell us a bit more about this pool and its equipment.
The pool is not used very much in the summer time. Theres only 2 people at home. I swim in it a few times in the summer. It gets used a few times a year with maybe 4-8 people. It uses 3: 1.0hp pumps that are single speed. It runs 3 sand filters. The plumbing is 2inch pipe.
- Feb 6, 2015
- 6,245
- Pool Size
- 12300
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
With a pool that is 3-10 times more volume than the average residential pool, you will probably need to keep the same amount of filters or get a large commercial sized filter.
Cartridge filters need to be disassembled to clean the cartridges, you can't backwash a cartridge filter. Something to consider as you would have 3 filters to disassemble instead of just backwashing them.
Besides being old, are there any issues with the present sand filters?
Whether you use the pool or not, you will still need to maintain chlorine levels to keep the pool water sanitized. With that sized pool, you certainly don't want an algae outbreak.
While filters don't aid in sanitizing, they will capture dirt and other debris.
Cartridge filters need to be disassembled to clean the cartridges, you can't backwash a cartridge filter. Something to consider as you would have 3 filters to disassemble instead of just backwashing them.
Besides being old, are there any issues with the present sand filters?
Whether you use the pool or not, you will still need to maintain chlorine levels to keep the pool water sanitized. With that sized pool, you certainly don't want an algae outbreak.
While filters don't aid in sanitizing, they will capture dirt and other debris.
Should i go with 3 500sqft filters or can i go with 3 200sqft filters?
- Feb 6, 2015
- 6,245
- Pool Size
- 12300
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
Bigger is always better when it comes to filters. The bigger the cartridge filter, the less often it will need to be disassembled and cleaned.
You may also wish to look into replacing the 3 pumps with variable speed pumps to save on electricity. You can run a VS pump at a lower rpm for a longer period of time for less electricity while still moving the same amount of water per day.
What is your present pump runtime schedule?
You may also wish to look into replacing the 3 pumps with variable speed pumps to save on electricity. You can run a VS pump at a lower rpm for a longer period of time for less electricity while still moving the same amount of water per day.
What is your present pump runtime schedule?
6 hours. Yeah i want to upgrade to cartridge filters because the sand filters are old and throwing sand back into the pool.
- Feb 6, 2015
- 6,245
- Pool Size
- 12300
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
All 3 pumps run for 6 hours per day?
Be aware, cleaning a cartridge filter is a minimum 1-2 hour time commitment each time - times 3 for your setup.
Backwashing a sand filter is a maximum 10-15 minute time commitment each time - times 3 for your setup.
3-6 hours (180-360 minutes) versus 30-60 minutes each time a cleaning is needed. Cleaning frequency will not change much.
Not trying to talk you out of cartridge filters, but be aware of the time it takes to properly clean them. I replaced a leaking 20+ year old (36"/700#) sand filter with a 420 sq. ft. cartridge filter two years ago. I don't notice any difference in the water quality or look of the water.
Be aware, cleaning a cartridge filter is a minimum 1-2 hour time commitment each time - times 3 for your setup.
Backwashing a sand filter is a maximum 10-15 minute time commitment each time - times 3 for your setup.
3-6 hours (180-360 minutes) versus 30-60 minutes each time a cleaning is needed. Cleaning frequency will not change much.
Not trying to talk you out of cartridge filters, but be aware of the time it takes to properly clean them. I replaced a leaking 20+ year old (36"/700#) sand filter with a 420 sq. ft. cartridge filter two years ago. I don't notice any difference in the water quality or look of the water.
- May 3, 2014
- 58,777
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
Switch to one large cartridge filter and one vs pump. Run it 24 hours per day at a low rpm.
That volume seems unlikely.
What are the dimensions?
The pool does not look that big in the pictures.
To get to 100,000 gallons, the pool would need to be about 34 x 68 x 5.8 feet deep.
Is the pool this big?
Is the pool this big?
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