New guy with questions about my old sand filter

[Doug520]

I'm neither a pro nor a pool enthusiast. I have a backyard pool that we enjoy. I have a very old Pentair TR100 sand filter. I bought the house with the pool already installed so I have no idea how many gallons it is. I'm not happy with the performance of the sand filter. It used to work very well, but now the water isn't as clear as it once was, and I get lots of algae when the water is warm. The guy who maintains the pool for me insists that I replace the sand filter with a cartridge filter. I don't want to go through that expense unless I have to. He says the pool water chemistry is correct, the algae issue is because the sand in the filter is worn out and would need to be replaced, so the pool isn't being properly filtered. The sand is about 7 years old, and the filter hasn't been opened since the sand was replaced. The sand has never been cleaned as I now read here is necessary. I'd like to make this filter work properly, as it used to work very well and I was pleased with the results.
The question comes to this. I have searched both on here and on Google, and it seems to be a 50/50 split in opinion - one half says the sand wears out and needs to be replaced. The other half says to deep clean the sand and it'll be fine, sand replacement is not necessary. Can someone please lead me down the right path here? If I need to replace the sand, I believe the TR100 takes 600 lb? So many varied positions on what sand to use, I'm very confused. That's if I even need to replace the sand rather than clean it. Does my pool guy sound correct that a sand filter with 7 year old sand that was never cleaned since it was put in would be so bad at filtering that even with correct chemistry the algae can still be an issue?

 

[JohnT]

Welcome to TFP!

Algae is 100% a chemical issue. Lack of chlorine. A pool guy who shows up once a week simply can’t properly chlorinate a pool.

 

[wireform]

Fire the pool guy if he said the sand wears out because no such animal exists.
Question #1 is how's he coming up with the chemistry levels, like where is getting his testing ?
Sand will only go bad if he used stuff TFP doesn't approve which can at times gum up the sand and not let it filter properly. A sand filter needs to be deep cleaned when it starts not filtering as it used to but only if the cause is debris but if it's gummed up it'll need to be replaced.
Deep Cleaning a Sand Filter

 

[Bperry]

Does my pool guy sound correct that a sand filter with 7 year old sand that was never cleaned since it was put in would be so bad at filtering that even with correct chemistry the algae can still be an issue?

Sorry to say (like the others did above) but your pool guy doesnt seem to know what hes doing. Algae is always caused by inadequate chlorination so your chemistry is not correct.

TFP works by advising people to test their own water heres an article with links to the two test kits recommended.

Swimming Pool Test Kits Compared

What pool test kit should I buy? Why not use test strips? Our recommended test kits will pay for themselves in no time!

www.troublefreepool.com

The best advice would be to add 5ppm of chlorinating liquid each day to the pool while you get a test kit ordered and we can help you clear up the pool. Its not hard and doesnt require a new filter.

 

[1poolman1]

I'm neither a pro nor a pool enthusiast. I have a backyard pool that we enjoy. I have a very old Pentair TR100 sand filter. I bought the house with the pool already installed so I have no idea how many gallons it is. I'm not happy with the performance of the sand filter. It used to work very well, but now the water isn't as clear as it once was, and I get lots of algae when the water is warm. The guy who maintains the pool for me insists that I replace the sand filter with a cartridge filter. I don't want to go through that expense unless I have to. He says the pool water chemistry is correct, the algae issue is because the sand in the filter is worn out and would need to be replaced, so the pool isn't being properly filtered. The sand is about 7 years old, and the filter hasn't been opened since the sand was replaced. The sand has never been cleaned as I now read here is necessary. I'd like to make this filter work properly, as it used to work very well and I was pleased with the results.
The question comes to this. I have searched both on here and on Google, and it seems to be a 50/50 split in opinion - one half says the sand wears out and needs to be replaced. The other half says to deep clean the sand and it'll be fine, sand replacement is not necessary. Can someone please lead me down the right path here? If I need to replace the sand, I believe the TR100 takes 600 lb? So many varied positions on what sand to use, I'm very confused. That's if I even need to replace the sand rather than clean it. Does my pool guy sound correct that a sand filter with 7 year old sand that was never cleaned since it was put in would be so bad at filtering that even with correct chemistry the algae can still be an issue?

A TR100 requires 600# of dry sand when installed. After 7 years it likely needs to have 50#-100# of sand added as some is lost each time the filter is backwashed. No, it doesn't wear out.
Get your chemicals in order, eliminate (kill) the algae, add a couple of handfuls of cellulose fiber (my preference) or DE after each backwash until the water is clear. Sand and algae aren't a good mix so adding a filter aid helps clear the water faster. After that, add it or not, your choice.
Usually a good, long backwash once a year is enough to keep the filter working well. A "deep cleaning" is OK if you want.