Need some (lots of) help diagramming my plumbing, backwashing DE filter, and troubleshooting Polaris

reefpool

Active member
Apr 12, 2020
34
Houston, TX
Hi there,

I've just purchased a home with a pool and it's my first time as a pool owner. I'm super excited to have found this site, because I'm having a lot of challenges! First things first, the pool is 50 ft x 20 ft and has an average depth of 7 feet (deepest end is 10 feet). It's massive... but presently we are trying to remedy multiple issues before swimming.

PROBLEM AREA #1) DE FILTER AT HIGH PRESSURE
Pool has a DE filter (Pentaire NSP 72) with the push style backwash valve. 12 days ago the seller had the DE filter cleaned by a pool company. I do not know whether they just cleaned it, cleaned and refilled DE, backwashed, backwashed and refilled. After this the pressure gauge was reading about 15 PSI, but now it is reading 35 PSI!!! Clearly I need to backwash this asap, but I have not found a good Youtube video for this model. Any instructions for this from the photo below? (REF PHOTO #1)

PROBLEM AREA #2) No clue what's up with this pool plumbing! Now, I've got a tiny bit of experience plumbing reef aquaria, but this thing has bare minimal valves and no labels on anything. These things coupled with my lack of experience in pools leaves me unsure what's going where, or how to do basic things like divert water to waste. Can anyone help me diagram this? (SEE REF PHOTO #1)


PLUMBING.jpg


PROBLEM #3) Polaris backflow valve may be shot- it's always shooting high pressure water out of that backflow tail and there is pretty much no suction at the body into the filter bag at all. Rather the thing just kinda wanders around past stuff on the bottom and nothing is being pulled in. Is this the only issue? There is also a leak at the wall (PHOTO #2) and the body has some apparent degradation (PHOTO #3)
WALL LEAK.jpg
POLARIS BODY.jpg

Thank you so much in advance for your time and help!
Angela
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
18,072
Northern NJ
Angela, welcome to TFP.

You have a slider valve in your filter. It only has two positions - FILTER or BACKWASH to waste. Read Slide Valves - Further Reading




I will diagram your plumbing tomorrow.

What model Polaris do you have? Post some clear pics of the complete hose and cleaner. I can’t tell what part of the cleaner the third pic is showing.

Please create your signature with details of your pool and equipment.

How are you chlorinating your pool? What test kit do you have?

Your filter pressure is probably high because you have an algae problem that is clogging your filter.

I suggest you read ABCs of Pool Water Chemistry and we can discuss how to deal with algae.
 
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clambert1273

Gold Supporter
Jun 13, 2013
629
Gilbert, AZ
AJ has you well covered but I popped in since I am a DE filter girl and the same type of push pull for mine.. for mine, I turn handle counter clockwise and lift up to start backwash.. I use timers and backwash 2 min then push down and turn it back clockwise and filter for 30-45 sec then repeat backwash for 1 min... it seems to work well for me.. after the last backwash, I put it back on filter and put my 4 scoops of DE in... I wait about 30 min THEN check pressure and record that. That 4 scoops is for me and about 80% of a full charge
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
18,072
Northern NJ
Below is your pool flow. It is really pretty simple.

Skimmers -> Pump -> Filter -> Return

You have a pickoff that can't be seen for the cleaner pump.

The pipe with a ?? are from something that was removed.

reefpool flow.jpg
 
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reefpool

Active member
Apr 12, 2020
34
Houston, TX
Hi there Allen & Christina!

Just put the signature in. I have made a little progress. First, thank you so much for the diagram. VERY helpful! I did ditch the pool service the prior owner had, the pool was doing poorly and was getting random people servicing it and I've now got it crystal clear! I have a feeling they were overfilling his pool purposely to keep it full of garbage and keep the need for the service up at worst, but at best just out of laziness in not having to fill it regularly with their visits. Before I let them go I had them repair timers they just installed and while the tech was out he was nice enough to take apart and clean out the water works in the Polaris 280 and now that's running just fine (great tool!).

I've done lots of skimming, brushing and I've lowered the water level and backwashed the filter and replaced just 4 scoops DE (supposedly 1 lb each) for the NSP 72 DE filter. I'm not sure if I did the backwash well or not, there is no window in the plumbing. The pressure returned to the "clean" level of 15 PSI. Does this mean I have sufficient DE? How can I know?? (Christina, is your filter the same size as mine?)

At present my free chlorine is 12ppm. I had shocked it and the kits I had were poor so thought it went down later but when I received the Taylor kit is read 13 ppm two days ago now it's about 12-12.5. I'm waiting on the Taylor T100 kit to arrive in the mail and meanwhile I have no tests because the store obviously has an issue testing since they had reported 8ppm on the FC. FWIW, their other numbers were CC 0; pH 7.6; TA 100; CH 350; CYA 40; TDS 1500. (but again, take it with a grain of salt. I'll do the measurements Monday. FWIW I'm a Ph.D. chemist so I can do a titration;)) When/at what FC level can we actually swim? The kids are anxious and the pool is so clean haha.

I'd like to add borates to the pool as we like the feel of saltwater but not a fan of corrosion and for my size pool I'd need a huge SWG to keep it up in Houston so I was thinking to stick with liquid chlorine and stabilizer and that perhaps borates might help the water feel. I was just going to go grab some Borax and HCl to do the job- probably do it this weekend but kinda nervous about these garbage test kits I have so I might wait for the good one.

I'd also like to install a multiport valve and a viewing window in the not distant future. I'll probably DIY that as I have some experience with plumbing reef systems. Any thoughts on other plumbing opportunities? One thing to note is that the whole pad has sunk in the back a bit. I'm not sure if it's worth waiting on plumbing to address that or if that's nbd. Thoughts?

Thanks so much. I'll be faster back next time:)
Angela
 
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ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
18,072
Northern NJ
I've done lots of skimming, brushing and I've lowered the water level and backwashed the filter and replaced just 4 scoops DE (supposedly 1 lb each) for the NSP 72 DE filter. I'm not sure if I did the backwash well or not, there is no window in the plumbing. The pressure returned to the "clean" level of 15 PSI. Does this mean I have sufficient DE? How can I know?? (Christina, is your filter the same size as mine?)
Without a clear window in your waste pipe you just have to waste water and judge when the waste water is clean.

My 60 sq inch DE filter takes 6lbs of DE. Your 72 sq inch filter should take maybe 7 lbs of DE after a breakdown cleaning and 80% of that or about 5.5 lbs of DE after a backwash.

At present my free chlorine is 12ppm. I had shocked it and the kits I had were poor so thought it went down later but when I received the Taylor kit is read 13 ppm two days ago now it's about 12-12.5. I'm waiting on the Taylor T100 kit to arrive in the mail and meanwhile I have no tests because the store obviously has an issue testing since they had reported 8ppm on the FC. FWIW, their other numbers were CC 0; pH 7.6; TA 100; CH 350; CYA 40; TDS 1500. (but again, take it with a grain of salt. I'll do the measurements Monday. FWIW I'm a Ph.D. chemist so I can do a titration;)) When/at what FC level can we actually swim?
Ignore pool store test results. They are inaccurate enough to just cause confusion. Just manage FC and pH until you get your TF-100 test kit.

We use the FC/CYA Chart. Let's assume the CYA 40 is accurate. Maintain a minimum FC of 3 and target your FC to be between 5-7 on a daily basis. Y0ur pool is safe to swim in at any FC level below SLAM FC which is 40% of CYA or 16 for CYA 40.

Let the kids jump in! :swim:

I'd like to add borates to the pool as we like the feel of saltwater
I suggest you wait on borates until you get a better feel for your TA and pH and get them under control.

Read Borates in pool - Further Reading

but not a fan of corrosion and for my size pool I'd need a huge SWG to keep it up in Houston so I was thinking borates might help the water feel. I was just going to go grab some Borax and HCl to do the job- probably do it this weekend but kinda nervous about these garbage test kits I have so I might wait for the good one.
Better to use Boric Acid from Duda Diesel which is in the link in the article above.

If you are using Liquid Chlorine then you pool may have salt already or it will over time. 2 gallons of liquid chlorine will rasie your FC by 4 and add 6.6 ppm of salt to the water. In a year of using Liquid Chorine you can have 2000 ppm of salt in the water if you don;t drain any water.

How are you chlorinating your pool?


I'd also like to install a multiport valve and a viewing window in the not distant future. I'll probably DIY that as I have some experience with plumbing reef systems. Any thoughts on other plumbing opportunities? One thing to note is that the whole pad has sunk in the back a bit. I'm not sure if it's worth waiting on plumbing to address that or if that's nbd. Thoughts?
Post complete pics of your entire pool pad and also the sunk area.
 

clambert1273

Gold Supporter
Jun 13, 2013
629
Gilbert, AZ
My fiter is smaller than yours I believe I have a hayward DE4820 So on mine after tear down cleaning is 6 lbs for full so after I backwash (I can't see mine either so I just use times) I do about 4 lbs back in, it seems to work for mine and if its happy Im happy lol
 

RDspaguy

In The Industry
Mar 21, 2020
709
Cabool, Mo

reefpool

Active member
Apr 12, 2020
34
Houston, TX
That’s okay I caught that:) meanwhile, big leak in that terrible push pull valve. I might have to spring for store price in multi port. They want 289$ for the part! I’ll just install it myself but it’s 140$ less online so I’m really not happy about that price. That’s for the Pentair. They have some generic cheaper but I feel I should probably go with the brand. Thoughts?
 

reefpool

Active member
Apr 12, 2020
34
Houston, TX
Okay so lots of issues came up suddenly! Isn’t that always the way?

1) that silly backwash valve is leaking at about 3drops per second- if it went up slightly it would be a steady stream. It’s creating a pool. They want 290$ for the multivalve and I might just grab it out of desperation and install in the morning.

2) husband removed the Polaris from the wall and didn’t replace anything in the port and I think this caused some issue. In any case I was convinced the filter was clogged due to too low DE and I backwashed 3x and then added 7 lbs. pressure is back to 15.

3) forgot to mention I now have one return line with air bubbles as well. There is a minor leak on the pressure side of return line above the pool I’ve photographed below. I’ll rip everything apart and replumb I guess tomorrow. We justmoved in a week ago so was hoping this would wait

To answer on questions:

- prior owner was using triclor tablets which I’ve removed. I have yet to use liquid chlorine but have it on hand.

-the pool pad holding filter is canted but not sure how long it’s been that way. Photo below. I’m sure the new pool of water isn’t helping!

-thanks for the tip on boric acid source. Okay I can wait until I have the kit and get this all stabilized. Appreciate the tip.

thanks, RD!


image.jpg
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
18,072
Northern NJ
You can replace the O rings in the slide valve which should fix the leak if you don’t want to do the MPV install now. There are youtube videos showing how to do it.

I would ignore the tilted equipment pad until you have a reason to replace the filter.

I don’t think turning on the booster pump without the Polaris connected will damage anything. The water will just jet out if the fitting. I have done it a few times.
 
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reefpool

Active member
Apr 12, 2020
34
Houston, TX
Hi guys. OK so you think even with the dripping and the pooling that's happening with the leak I could still wait on the MPV? I can order that online now and maybe I can install next weekend. Should I meanwhile replace the o-ring or nbd on the dripping? Can I grab that at a pool store? HD?

So, good news is my chem kit arrived! I have a couple questions.

First, I collected all of the data and then did the SI calculation. Because my FC was quite high I did do the chlorine neutralization before running the pH and alk tests. The SI calculator I used online (pentair) does the correction of alk for CYA level. Here are my numbers:

pH = 7.6
FC = 12-13
CYA = 52-53 (I am pretty sure I could not see the dot anymore at this point, despite it sticking in my brain)
Alkalinity measured = 105
Alk corrected for CYA = 88
CH = 365
Temperature = 75
TDS (using TDS meter that only reads to 999) = 120

It seems from the CYA/FC chart that my target for this high level of CYA is 6-8 ppm FC and SLAM level would be up at 20ppm FC. So I guess the kids can swim!

The SI by the calculator online is +0.17. The calculator says this is OK and the Taylor book agrees. Is there any reason to do some water change in the pool at all at this point? Just let it ride?

Funny about the comment on the electric bill. Ours was a monster just for the week! We were running everything 24/7. Thoughts on timing? This is a very large pool and the deep end is very deep for diving so I do want to maintain circulation. That said, it's pretty clean now except some dead bodies (algae) that I need to vacuum into the filter. Will be doing that tomorrow.
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
18,072
Northern NJ
Please use PoolMath. It does all the CSI corrections for you and keeps us all on the same page for comparison.

FC & pH are fine.

If the dot disappears between 60 and 50 we round up and call CYA 60. We only deal with round numbers and the CYA lines are logarithmic, not linear, and you can’t eyeball values between the lines.

TDS is meaningless to us - TDS - Further Reading

CSI between -0.3 and +0.3 is fine. Preferably keep your CSI on the negative side.
 

reefpool

Active member
Apr 12, 2020
34
Houston, TX
Thanks AJ. One quick question also, when you shut the pump off is the filter supposed to drain back to pool? I’m wondering if this is abnormal and whether it impacts my DE at all that it drains every shutdown.
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
18,072
Northern NJ
Thanks AJ. One quick question also, when you shut the pump off is the filter supposed to drain back to pool? I’m wondering if this is abnormal and whether it impacts my DE at all that it drains every shutdown.
That is normal if your equipment is higher then your pool. You can put a check valve in the suction line to the pump to prevent that. But if your pump starts and primes well it does not effect your DE and I would leave it as is.