Problem with my filter

[Paul.]

Hi everyone, this is my first post on the site,

I am a new homeowner and purchased a home last year that included an above ground pool.
I was told very little about the pool by the old home owner and have been learning as I go along. I had used the pool all of last summer without much incident. I had purchased a new 55btu heater, since the old one was rusted becuase of the salt water. (the model was suggested to me by my local pool store).
When I purchased the pool last year, I was told by the homeowner that the sand was due to be changed. Nearing the end of last summer season, I had the sand changed by the pool store. When the sand was changed, I had noticed that sand was entering the pool. I was told by the pool store that this was normal and that it would go away when the sand settled. I vaccumed the pool on waste, and it went away. I winterized the pool properly at the end of the season.
At the beginning of this season, I noticed that the filter seemed to not work properly. It seems like the bigger particles are not being filtered and are going back directly into the pool. Everytime I vacuum the pool (on filter), it seems that everything goes back to the bottom of the pool within hours. Contacted the pool store and was told that the particles I see in the pool may be too fine to be removed by the filter, and suggested I vacuum it on waste. This seems to be very inconvenient because I am losing whatever chemicals I put into the pool, (cya, salt etc.) and seems to add up to an extra cost.
So I decided to try out the efficacy of the filter. As I was adding the CYA into the pool, I decided to vacuum some of it out to see if it would return into the pool. And to my surprise, it did!
My pool store does not really seem reliable to be since all of my questions concerning my filter, and chemicals do not seem very helpful.
I have been using the TFP method to balance out my water and everything seems to be fine.

Just wondering if anyone could help me out with any ideas on what might be wrong with my filter and if I might need to replace it for next season. If it helps, I have a 5 function valve on the filter, not sure of the brand since the markings have been erased over the years. I experimented with the different valve functions, and I found it odd that circulation was still possible when the valve was on "winterize". I thought that winterize was supposed to close all ports. Could it be the head of the filter that is the problem?


FC: 9.92
CC: 0
PH: 7.2
CYA: 80
TA: 90
Calcium Hardness: 343
Salt: 3300
Borates: (currently researching, might add them next year, since the season is almost over).

Thanks for any information,

Paul.

 

[YippeeSkippy]

Are you able to open the filter up and check to see if there is *enough* sand in there? Is the sand channeled, which diminishes filtration? Can you inspect the sand and confirm that the pool guy put the right type in-I refer you to this recent thread here on TFP:
My findings on how not all sand is created equal

 

[Bama Rambler]

It sounds like they may have broken a lateral when replacing the sand or that the spider gasket is out of place. It's pretty easy to remove the top of the multiport valve and inspect the gasket, and even replace it if needed.

FYI. Winterize opens all the passages so the valve will drain. Closed, (if your filter has that position) closes all the passages.

 

[Paul.]

Thanks for the help ?

I went to the pool store and got the gasket. I was going to take apart the multiport valve to change the gasket, but it was all rusted shut. All the screws were snapping as i was removing them.
Went to the pool store and asked how much to replsce the valve completely. It would have cost 136$ to replace the valve of the 15 year old filter, not knowing if it would fix the problem. A new filter was on sale for a cost 200$. Seemed like a safer choice.