My Grandmother Threatened to Blow Up Her Pool Every Year
True story.
Every spring, it took her three to four weeks to get that pool clear. She’d dump in clarifier, shock it to death, run the filter around the clock – nothing worked. She was ready to dynamite the thing.
What I know now, after 30+ years in this business that I didn’t know as a boy, is that her problem wasn’t the chemicals. It was her filter and how she used it.
She had a DE filter – supposedly the “best” type – but it was undersized for her pool, and she never added the right amount of DE powder. So this undersized filter, running without enough media, was basically just circulating dirty water.
I’ve seen the same thing hundreds of times on service calls. I’d show up to a frustrated homeowner’s backyard and find empty bottles of clarifier, jugs of chlorine everywhere, all the “solutions” the pool store sold them. They finally threw up their hands and called a pro.
Nine times out of ten, the problem was a dirty filter.
PRO TIP: Burn this into your brain, pool filters are not made big enough to clean a dirty pool. Yeah i said it! They are made and sized to keep a clean pool clear. If your pool has debris, get it out, if your pool is full of green algae, kill it and get it out, if there is a bunch of dirt in the pool, get it out FIRST, or plan to clean and refresh your filter 5-8 times. Seriously, I would show up with chemicals, an inground pump, a leaf rake, and a brush. Throw in the chemicals, brush the walls, and vacuum with my pump all the dead algae and sediment straight to waste, never try to filter it if your pool is dirty dirty.
The Dirty Secret About Pool Equipment Packages
Here’s something most pool dealers won’t tell you: they include cheap, undersized filters to hit a price point.
That Intex package with the “included filter system”? It wouldn’t be adequate for a Barbie dream house pool. It’s there so they can advertise a low number. You pay for it later in frustration, chemicals, and wasted weekends.
The savvy shopper researches filters before buying a pool. I hope that’s why you’re here.
The Three Types of Pool Filters (Quick Version)
I’m not going to write a dissertation. Here’s what you need to know:
Sand Filters – Least Efficient
- Filtration: down to 40 microns (about the size of a grain of salt)
- Maintenance: Backwash when pressure rises – no disassembly needed and easy to winterize
- Best for: Budget-conscious buyers, people who are NOT mechanically inclined.
- The honest take: Sand gets a bad rap, but for someone who wants simple maintenance and a low price, it’s a solid choice. Backwash, done.
Cartridge Filters – Middle Range
- Filtration: down to 20 microns (medium particles)
- Maintenance: Remove cartridge, hose it off. No backwashing = less water waste.
- Best for: Most above ground pool owners, people who want better filtration without the hassle of DE
- The honest take: This is what I recommend most often. Good balance of performance and ease. You’ll hose off the cartridge a few times per season – that’s it.
DE (Diatomaceous Earth) Filters – THE BEST
- Filtration: down to 4 microns (finest particles – catches almost everything)
- Maintenance: Disassemble and clean, but must add DE powder after each cleaning.
- Best for: Water clarity perfectionists, night swimmers (sparkling water shows under lights)
- The honest take: If you prefer less maintenance, and you want the clearest water possible, DE is the answer.
Size Matters as much as Type
You cannot oversize a pool filter. Bigger is always better.
A larger filter means:
- Longer time between cleanings
- Better water flow
- Less strain on your pump
- Faster clearing when you open in spring
Above Ground Filter Systems | What I Actually Recommend (and Sell)
I only carry products I’d put on my own pool. Here’s my honest equipment ladder:
Best Value for Smaller Above Ground Pools
SPLA 120 sq ft Cartridge + 2-Speed Pump Package
- Oversized for pools up to ~9,000 gallons / decent size for a 24 round size pools
- Great value, reliable, gets the job done
- Have had better satisfaction than with Hayward
Best All-Around for Above Ground Pools
Hayward XStream 150 Cartridge Filter System + Speck E71-II Variable Speed Pump or Hayward 2-Speed Pump
- My go-to recommendation for most above ground and semi-inground pools
- Complete system: filter, hoses, clamps, union, gauge, base/platform
- Variable speed pump = serious energy savings
- Works for semi-inground pools if the pump is below waterline (gravity feed)
Best DE Filter for Above Ground
Hayward EC40/45/50 Series DE Filters
- If you want DE filtration for an above ground pool, this is the one
- Bump handle for extended cleaning cycles
- Rock solid reliability
Money No Object
Pentair DE Quad 60
- An inground filter, but works beautifully on larger above ground and semi-inground pools
- Massive capacity = clean your filter once a year when you close the pool – that’s it
- The Cadillac of pool filters – You are going to shell out roughly $800 more but you will love your life!
Inground Filters
Sand is sand, Sand filters have been around and working fine since the Roman days (Think Chariots of Fire). And they cost the least. Really a commodity, so the brand doesn’t even matter. It’s the sand that filters the dirty water and algae, so just get one that holds a couple hundred pounds of sand (recommend white Silica filter sand).
Cartridge Inground Filters – Most are either Hayward or Pentair – I prefer Pentair mainly because they keep innovating and their customer service, and tech support is 20X better than hayward. Pentair has a great line of cartridge inground filters called Clean and Clear
DE is the Best – Just a fact! My go to is Pentair Quad 60, but for larger pools, maybe size 20×40, I’d go with the Quad 80.
Bottom Line
Don’t let a cheap filter ruin your pool experience. Whether you go sand, cartridge, or DE – get one that’s properly sized for your pool.
And if you’re buying a pool package? Make sure you know what filter is included..
Questions? I’ve been doing this for 30 years. [Call me] or [browse pool packages].
Q: Can I use an Above Ground Filter on an Inground Pool?
A: Yes, but only if you have a variable speed pump. Inground filters are designed for inground pumps that move 80 gallons a minute. Above ground filters are designed to handle 30 gallons a minute, so if you cut the speed way down on the pump you can use the above ground filter.
What’s The Best Pool Filter?
A: DE (Diatomaceous Earth) filters filter out the smallest particles, The comes cartridge, then sand filters come in last.
Which Pool Filters Cost the Least?
A: The cheapest pool filters are sand filters.
Which Above Ground Pool Filter do I recommend the Most?
A: The Hayward XStream 150 cartridge filter, and I like to pair it with a 2-speed or variable speed pump. The slower you move pool water the easier it is for your filter to clean the water.
Mike Kern is a Certified Pool Operator and owner of MGK Pools Inc in Massachusetts. He’s installed thousands of pools and has strong opinions about filter sizing.
