Hello Everyone - I've had a recent repeating problem with my 7 year old Pentair TR100 filter. I've never changed the sand in it that cleans the water and the guy at the pool store is telling me that the sand needs changing. It makes sense how he describes the problem. Does anyone out there know where I could find instructions on how to change the sand in this filter? I appreciate the help!
Pentair TR100 Filter
- Thread starter rjaysea
- Start date
The water in the pool is turning green. I've added a lot of chlorine and various other chemicals, based on the results of the water tests at the pool store, and within a day or two it starts to turn green again. When I take the water to the pool store, the guy says there's no chlorine left. I tell him I can't keep buying chlorine, that there has to be another problem. He started asking me questions about the filter. When he found out that I never changed the sand, he said that was the problem. He said that as the sand filters the water over and over, eventually the sharp edges on the sand are worn down and it doesn't do a good job. And he also says the sand gets dense and the pressure in the filter will go up, and it has. Does he sound correct?
Okay, well the sand definately needs to be changed. Chlorine users want to change the sand every 3-5 years. Also, has the pool store checked for phosphates and/or Nitrates? They can have a big impact on chlorine residual. What type of chlorine are you using? How long have you noticed that the pool wasn't holding a chlorine level? Is it something recent?
Your pool problem has nothing to do with sand. It is because of inadequate chlorine in your pool. You need to start reading in pool school and understand the function of chlorine.....that's what keeps your pool from turning green. There are many here on the forum who's sand is older than 10 years. Mine is 6-7 and the pool is sparkling.
There is also a good chance you have no CYA which adds to your chlorine loss.
In any event, if you can post a complete sete of test resuilts, we will all hel[p you get your pool crystal clear.......but it's going top take chlorine.....there's no other way.
There is also a good chance you have no CYA which adds to your chlorine loss.
In any event, if you can post a complete sete of test resuilts, we will all hel[p you get your pool crystal clear.......but it's going top take chlorine.....there's no other way.
Hi rjaysea,rjaysea said:
What we really need is a full set of water test results. You are fighting algae and we can't help without knowing the numbers. We need:
FC
CC
pH
TA
CH
CYA
The sand in your sand filter is probably just fine. The pressure goes up when it is trying to clear algae and junk from a pool. That is normal. What is your clean psi reading and how high is it reading? Usually, we backwash when the psi rises 6 higher than the clean filter psi.
It would also be helpful to have your pool and equipment specs added to your sig.
Go to Pool School (upper right button) and read the first few articles.
They will explain how to add the needed info.
Welcome to the forum
katthepoolchick said:
Kat...this is simply not true about sand. Sadly this seems to be another case of an overstabilized pool with inadequate chlorine levels. Phosphates and Nitrates may help algae live, but chlorine kills algae
To the OP...click on poolschool...read it thouroughly, get a good test kit and be prepared to shock your water with liquid chlorine...we have an article for the shocking process as well
Whatever issue you may or may not be having with the sand, it has nothing to do with the pool being green. Old sand doesn't filter quite as well, but the difference is small and will not cause the pool to turn green. Many people never change their sand, and they don't have any significant problems because of that. After seven years, it is a reasonable time to change the sand, but doing so won't solve your current problem.
I am sure we can help you solve your current problem, but to do that we need a full set of water test results, as Butterfly suggested.
I am sure we can help you solve your current problem, but to do that we need a full set of water test results, as Butterfly suggested.
I didn't state that the sand change was going to get rid of the green pool. The reason the pressure on a sand filter increases is due to dirty sand. If you are having to backwash a filter once a week that is too much. When your sand is that old it can take longer to clean the pool up. I do not disagree with the fact that chlorine is going to clear the pool up, but in order for you to get the most effectiveness from your shocks, you need to have a good pH level as well as a cyanuric level of at least 30ppm. I deal with pools everyday and I usually can clear a green pool up within 48hrs. If you remove high phospahtes then algae won't have anything to eat to grow. Natural Chemistry have great phosphate products.
Thanks for all the feedback! OK, here are the test results that I just received about an hour ago (4 pounds of chloro bright chlorine were added two days ago):
FAC - 0 (!)
TAC - 0 (!)
CYA - 95 (OK)
TA - 100 (OK)
pH - 7.2 (OK)
TDS - 1700 (OK)
Pho - 2000 ppb (Wow!)
The phosphate condition was probably always there, but we just didn't notice it. So now, I running the pool for 48 hours with 3 liters of PHOSfree from Natural Chemistry. I'll get back to you all in a couple of days!
FAC - 0 (!)
TAC - 0 (!)
CYA - 95 (OK)
TA - 100 (OK)
pH - 7.2 (OK)
TDS - 1700 (OK)
Pho - 2000 ppb (Wow!)
The phosphate condition was probably always there, but we just didn't notice it. So now, I running the pool for 48 hours with 3 liters of PHOSfree from Natural Chemistry. I'll get back to you all in a couple of days!
Given how high your phosphate level is, PhosFree is going to be both expensive and troublesome. I really don't recommend it. Having phosphates in the pool is really not a problem, my phosphate level is around 4,000 (and has been higher) and I never have any problems. Pool stores push phosphate removers because it makes them money, not because it is a good solution for the problem you are having.
Your fundamental problem is the high CYA level. High CYA levels make chlorine less effective than it would be at lower CYA level. You have two choices, either lower the CYA level or use massive amounts of chlorine to compensate for the high CYA level.
I recommend replacing about 40% of your water with new water, to get your CYA level down to around 60. Then shock the pool with a chlorine source that does not contain CYA, preferably liquid chlorine or bleach.
Chlor Brite contains CYA. Every time you use it your CYA level goes up and it becomes more difficult to keep your pool sanitized.
Your fundamental problem is the high CYA level. High CYA levels make chlorine less effective than it would be at lower CYA level. You have two choices, either lower the CYA level or use massive amounts of chlorine to compensate for the high CYA level.
I recommend replacing about 40% of your water with new water, to get your CYA level down to around 60. Then shock the pool with a chlorine source that does not contain CYA, preferably liquid chlorine or bleach.
Chlor Brite contains CYA. Every time you use it your CYA level goes up and it becomes more difficult to keep your pool sanitized.
