I'm looking to replace my sand filter with a cartridge filter

[JayH]

My pool is near 19,000 gallons and I currently have a 2 speed Pentair 347992 Optiflo pump. It's 1 1/2 HP on high and 0.19 on low. My pool is above ground.
In the fall, I remove the sand from the filter to remove the stand pipe. I do this because once, despite draining the sand filter, the sand froze and cracked the plastic stand pipe. For $100 I was able to get another one. Anyway, when I was saving the sand in 5 gallon buckets, probably in October, I was surprised by the dirty water coming to the top of the buckets. I expected the sand to be clean because I backwashed the sand as I lowered the water in the pool for winterization. I didn't do the math but naturally I backwashed many gallons of water. I also didn't find the clarity of the water that great and different times I "vacuumed to waste" to get rid of some fine sediment.
Anyway, if someone could help me with what cartridge filter they would get if it was their pool I'd be appreciative. I realize I will get different answers but I read all the answers and go from there. Thank you!

 

[mknauss]

For your area and pool volume I would get at least a 300SF cartridge filter. You likely would need to clean after the initial burst after opening and then again at closing.

 

[generessler]

My pool matches yours pretty well in size, pump hp (when I had a single speed pump; it's vsp now). It has a 14-year old Pentair Clean and Clear Plus, 320sf. Works well even with the pool surrounded by trees that shed stuff most of the year. Cleaning is every 4-8 months. Many here recommend buying the biggest filter you can afford for less cleaning. CCP's come in bigger sizes than mine. Not cheap, but seems a quality product.

 

[thefloatqueen]

I went from sand to cartridge last summer and will never go back!! Get the largest one you can afford, even if it’s overkill. I would go at least 300 square ft for your size pool. My AGP is only 7,500 gallons and my filter is 150 sq ft which is way more than necessary but I LOVE it.

 

[JayH]

I went from dance to cartridge last summer and will never go back!! Get the largest one you can afford, even if it’s overkill. I would go at least 300 square ft for your size pool. My AGP is only 7,500 gallons and my filter is 150 sq ft which is way more than necessary but I LOVE it.

Possibly off topic but hopefully helpful...I notice that you are running a 1.5hp single speed pump. Please consider a 2 speed or a variable speed pump. That 1 1/2 hp is expensive to operate! I have a two speed and I only use the 1 1/2 setting when I vacuum otherwise I run it on 0.19 hp. You may save the money you spend in a year or a year and a half? It's much quieter too.
Thanks for your confirmation of myself getting a cartridge filter and also reinforcing the size too.

 

[duraleigh]

Your description of your sand filter woes sounds more like not enough cleaning of the filter. If that's the case, a cartridge may not help you. Sand filters should be deep-cleaned each year and will always capture visible sediment.

Cartridge filters are great but I don't think the sand filter was your problem.

 

[thefloatqueen]

Possibly off topic but hopefully helpful...I notice that you are running a 1.5hp single speed pump. Please consider a 2 speed or a variable speed pump. That 1 1/2 hp is expensive to operate! I have a two speed and I only use the 1 1/2 setting when I vacuum otherwise I run it on 0.19 hp. You may save the money you spend in a year or a year and a half? It's much quieter too.
Thanks for your confirmation of myself getting a cartridge filter and also reinforcing the size too.

Thank you for the info! Ideally, I would get a variable speed pump but electric is pretty cheap here and I don’t run it 24/7 unless I have to. My pool is only 7,500 gallons. I am eyeing a SWG right now so that’s what I’m trying to budget for first. I wanted to get either a SWG or a heater this season (I can’t afford both at the same time, let alone adding a VSP to the mix lol). After I get those, I’ll consider upgrading my pump.

 

[Flying Tivo]

I have 5 years on my sand filter and will never change it. If you have expensive water, then cartridge would be the best option.

 

[Newdude]

The average human eye can see about 100 microns and a sand filter removes 3.3 times smaller than that down to 30 microns. Once the filter starts collecting crud, the crud traps even finer crud no matter which filter you are using.

Because of this, I believe that your environment determines how low your filter will filter, no matter which of the 3 you choose.

If you are seeing stuff in the pool, either the filter has an issue, or the stuff simply didn't make it there, such as the heavier sediment that settled on the floor. No filter will get that without brushing/ vac-ing. Any floating particles you see will eventually find the filter, they just haven't found it yet.

My old place had a bunch of oak trees that dropped particles all season. It might take 2 days for the floating particles to find the filter, at which point many new floating particles had been added. I came to learn that it was a neverending battle, even with 24/7 operation.

 

[thefloatqueen]

The average human eye can see about 100 microns and a sand filter removes 3.3 times smaller than that down to 30 microns. Once the filter starts collecting crud, the crud traps even finer crud no matter which filter you are using.

Because of this, I believe that your environment determines how low your filter will filter, no matter which of the 3 you choose.

If you are seeing stuff in the pool, either the filter has an issue, or the stuff simply didn't make it there, such as the heavier sediment that settled on the floor. No filter will get that without brushing/ vac-ing. Any floating particles you see will eventually find the filter, they just haven't found it yet.

My old place had a bunch of oak trees that dropped particles all season. It might take 2 days for the floating particles to find the filter, at which point many new floating particles had been added. I came to learn that it was a neverending battle, even with 24/7 operation.

I never knew this! Very interesting. Makes sense now that I think about it lol

 

[Newdude]

I never knew this!

It took 10 years as an unsanctioned gunkologist. My only credentials were the pool and 80 oaks. But if this crud was really doing the filtering, then the same crud would be in any of the 3 filters, leveling the oft debated playing field.






The sand filter might take a little longer to get to this point after cleaning, but it would get there too eventually.

 

[JayH]

The average human eye can see about 100 microns and a sand filter removes 3.3 times smaller than that down to 30 microns. Once the filter starts collecting crud, the crud traps even finer crud no matter which filter you are using.

Because of this, I believe that your environment determines how low your filter will filter, no matter which of the 3 you choose.

If you are seeing stuff in the pool, either the filter has an issue, or the stuff simply didn't make it there, such as the heavier sediment that settled on the floor. No filter will get that without brushing/ vac-ing. Any floating particles you see will eventually find the filter, they just haven't found it yet.

My old place had a bunch of oak trees that dropped particles all season. It might take 2 days for the floating particles to find the filter, at which point many new floating particles had been added. I came to learn that it was a neverending battle, even with 24/7 operation.

Thanks for the thoughts Newdude. I started using a filter sock last year and I think that it would help you with your floating particles. I am not troubled with trees but, in the spring, my pool does seem to catch a lot of pollen. A real lot. But I use it all summer though. The brand I use is Splash Pro.
It's possible that the material that was making its way through my sand filter last year was iron. I have used Pro Team's Metal Magic and I think when I vacuum that it just goes right through the sand and redeposits. Whatever it was, I ended setting the dial on my sand filter to "Pump to Waste". Ultimately, after much frustration, I searched here on TFP's and saw that someone had connected a Colligan filter cartridge to the end of their hose to filter the water before it goes into the pool. I'm not sure if I'm using a P5 or a P1 (unfortunately) but because of its iron color I know it is working.
One thing is for sure, the sediment on the bottom off my pool was not from an absence of vacuuming. Paramount for me is that I am suppose to enjoy my pool. If a cartridge filter helps with that then I will get one, if it won't then I won't. But last summer the pool was really just an ongoing problem and, straight up, I don't need that.
I know the included 1 1/2 hp pump in my pool package was junk I don't know if all sand filters are pretty much equal or not but because of the pump I am assuming that if there is a cheaper one I probably got it too.

 

[Newdude]

One thing is for sure, the sediment on the bottom off my pool was not from an absence of vacuuming.

Unfortunately there is only so much a filter can do. Obviously, acorns and such drop like bricks but plenty of dusty/pollen stuffs sink too.

I started using a filter sock last year and I think that it would help you with your floating particles

The suspended stuffs are slooooooooow to find the filter. I'd swim around with a mask and even with me bobbing around right next to them disturbing the water they'd sit in their spots unaffected. They all eventually made it to the filter but of course the new ones looked exactly like the old ones. Lol.

My filters are big and even when they're nasty by my standards, the pressure hasn't increased by enough to warrant the cleaning.
I don't mind cleaning them and it's so infrequent that I don't fuss with hair nets, but I happily rec then for anyone who wants to extend the cleanings even further. They are amazing.

 

[duraleigh]

One thing is for sure, the sediment on the bottom off my pool was not from an absence of vacuuming.

More and more, it is sounding like the sediment on you pool floor is dead algae. How do you test? How often do you test? Can you post current test results?

 

[JayH]

More and more, it is sounding like the sediment on you pool floor is dead algae. How do you test? How often do you test? Can you post current test results?

I have to go by memory here because my pool is still covered until about Memorial Day. I do remember shocking the pool last season and even doing an overnight test. However, I suppose that the bacteria may still have needed time to settle out of the water. This sediment problem just seemed to go on and on. I use a Taylor K-2006 and TFP's recommended ideal levels for vinyl pools with liquid chlorine. I printed them out and keep them in my Taylor kit. I use liquid chlorine to avoid too much cyanuric acid even though I would prefer tablets and I don't use the Calcium Hypochlorite tablets because my well water is already as hard as nails.
Anyway, the annoying deposits on the bottom of the pool do have an iron color to them. They are here and there, maybe taking up areas maybe 9 inches x 13 inches? They are easily disturbed. If only I had a picture. The water was clear. We were adding water frequently last year due to what I was hoping was evaporation but now I know I have a water leak because I have needed to add water this winter under my cover because of it sinking into the pool too much. So, if it is the result of my well water, somehow, there was a lot of it added.
Thank you to everybody who has contributed to this thread!

The average human eye can see about 100 microns and a sand filter removes 3.3 times smaller than that down to 30 microns. Once the filter starts collecting crud, the crud traps even finer crud no matter which filter you are using.

Because of this, I believe that your environment determines how low your filter will filter, no matter which of the 3 you choose.

If you are seeing stuff in the pool, either the filter has an issue, or the stuff simply didn't make it there, such as the heavier sediment that settled on the floor. No filter will get that without brushing/ vac-ing. Any floating particles you see will eventually find the filter, they just haven't found it yet.

My old place had a bunch of oak trees that dropped particles all season. It might take 2 days for the floating particles to find the filter, at which point many new floating particles had been added. I came to learn that it was a neverending battle, even with 24/7 operation.

I think that the human eye can see down to 5 microns but I am not an ophthalmologist!

 

[Newdude]

I think that the human eye can see down to 5 microns but I am not an ophthalmologist!

.1mm per the googs. (100 microns). Even if it's off by a couple dozen microns a sand filter can still do 2X what we can see.

 

[JayH]

I have to go by memory here because my pool is still covered until about Memorial Day. I do remember shocking the pool last season and even doing an overnight test. However, I suppose that the bacteria may still have been suspended and needed time to settle out of the water. This sediment problem just seemed to go on and on. I use a Taylor K-2006 and TFP's recommended ideal levels for vinyl pools with liquid chlorine. I printed them out and keep them in my Taylor kit. I use liquid chlorine to avoid too much cyanuric acid even though I would prefer tablets and I don't use the Calcium Hypochlorite tablets because my well water is already as hard as nails.
Anyway, the annoying deposits on the bottom of the pool do have an iron color to them. They are here and there, maybe taking up areas about 9 inches x 13 inches? They are easily disturbed. If only I had a picture. The water was clear. We were adding water frequently last year due to what I was hoping was evaporation but now I know I have a water leak because I have needed to add water this winter under my cover because of it sinking into the pool too much. So, if my problem is somehow the result of my well water there was a lot of it added.
Perhaps with my lifestyle of having 4 minor children and a senior parent living in the house I am not giving the pool maintenance it requires regardless of filter. But, if a cartridge filter will help to achieve a better experience than I will get it.
Thank you to everybody who has contributed to this thread!

 

[Newdude]

Perhaps with my lifestyle of having 4 minor children and a senior parent living in the house I am not giving the pool maintenance it requires regardless of filter

^^^^this. Life has a way of getting in the way for all of us. If you want a pool on easy mode, consider a SWG. At 19k gallons it will more than pay for itself over its lifespan at today's chlorine prices.

I spent about 20 mins on sanitation from June to November, including getting the test kit from the closet and getting a pool sample. Brushing / Vacuuming, and the other parameters will require their normal attention, but they all are forgiving in the short term and you won't be green when you have the time to work on them.

*disclaimer that I'm a decade in with SWGs and it's second nature now. There will be some learning curve if you switch so you won't be 0 to Easy Street, but even with the learning curve, your sanitation demands will be drastically reduced on day 1 as you learn.