Water Clarity/Sand Filter Help

Jul 6, 2016
34
Mebane/NC
Hi All,

I need some major help with my pool. I've had a green pool over the winter due to equipment changes and then a delayed shipment on chlorine pucks. Due to the pandemic, bleach was too hard to find last summer/fall so I used pucks to keep the chlorine in check. Once the CYA got to around 50 I stopped using the pucks due to winter approaching. Fast forward to two weeks ago: in preparation for installing the CircuPool Core 55 SWG, I got the water balanced and was fortunate enough to find liquid bleach. The pump was running 23 hours per day. Once the water was balanced for the SWG, I installed the SWG last weekend. I tested the SWG by taking some before and after Chlorine readings to make sure it was working (works great), but then turned the SWG off while I did the SLAM process to get the water clear. Pump still running 23 hours per day. A week has now passed and the water clarity has not changed a bit. Looked for sand in the sight glass and backwash, no sand visible. Took the valve off my Hayward S244T (Valve SP0714G11) to check the spider gasket and it looks fine. I then decided to deep clean the sand utilizing the Deep Cleaning a Sand Filter instructions. Water in the sight glass and passing through the clear CORE 55 SWG look clear. I just checked the water this morning and the pool clarity has not changed a bit in over two weeks. The only thing I noticed is the pool water changed from a deep green to a reddish brown color once the SLAM was underway, but it has looked like brown pond water for two weeks now. I'm not expecting the pool to be crystal clear within a few days or anything, but I should be seeing some improvement by now. The ONLY thing I'm a little concerned about is the amount of sand that was in the filter. I put 300 pounds in 5 years ago when I installed it but I had to put the garden hose a good ways down before I hit sand. I'm not seeing sand anywhere so I'm assuming it's all still in there but it seems low to me. Other than adding sand, I'm at a complete loss as to why my water is not clearing up. Here's my latest readings from TF100 and the Pool Math app:

FC: 32
CC: 0
PH: 7.5
TA: 80
CH: 50
CYA: 70
Salt: 3070

Thanks in advance for reading through this long post.
 
Just checked everything again and the sight glass and return side of the SWG is clear. Here's some pictures and one of the pond I'm dealing with.
 

Attachments

  • A716AAFA-662E-4099-AA55-EF235DE12D71.jpeg
    A716AAFA-662E-4099-AA55-EF235DE12D71.jpeg
    374.9 KB · Views: 21
  • 0D7C5E70-79AB-42F5-8536-43A4CFE9132E.jpeg
    0D7C5E70-79AB-42F5-8536-43A4CFE9132E.jpeg
    460.2 KB · Views: 21
  • 732019F2-0380-4284-97AE-A894BBB7A286.jpeg
    732019F2-0380-4284-97AE-A894BBB7A286.jpeg
    1.1 MB · Views: 21
How often are you checking your FC?

Log all of your tests and amounts of FC added either here or in PoolMath. If you are using PoolMath please share the logs.

Take your water to a pool store and have the water tested for metals. I suspect you have an iron problem in the water causing the brown color.

@mknauss
 
You are not losing FC like you would if you had algae and you show no CC.

I suspect you have iron in your water.
 
Ok, so some updates on this over the past few weeks. I had the water tested for metals at the pool store and copper and iron came back at 0.00. I noticed some water passing through the SWG when the filter was in backwash/waste/rinse so I installed a new handle assembly. Water flowing properly after install. Water still not getting clear. Pool store lady is stumped and recommends using Stain Free which I had a spare bottle. Added Stain Free and no change in water clarity after a week. I’m at a loss. Is it possible I have a broken lateral? Backwash is dirty so the sand is capturing something, but clarity hasn’t changed...any ideas?

FC: 10
CC: 0
PH: 7.5
TA: 80
CH: 50
CYA: 70
 
I checked it about 2-3 weeks ago. Opened it up and did the cleaning procedure. The sand itself seemed fine and I moved it around a bit with the hose. My only concern was the amount of sand in the filter since it seemed low. It was below the halfway point, but I put the recommended 300 pounds in when I first installed it. I haven’t seen any sand in the sight glass or backwash (can’t tell if it’s in the pool since the water is so bad). I’m going to do the sock test this weekend and check the laterals as well. At this point I’m not sure what else to check.
 

Enjoying this content?

Support TFP with a donation.

Give Support
What type of sand did you use in the fiter?

 
It was regular pool store sand. It was put in 5-6 years ago so I don’t recall the brand. But it was just regular pool sand, nothing special.

Did you read the link above? Some pool store sand is better then other.
 
Yeah I’ve read that link in the past. Unfortunately it was so long ago I don’t remember the specifics. I’ve had crystal clear water every year until now so I think the sand was fine. I’m leaning towards a broken lateral at this point since the sand was much lower than I expected. I’m taking it out Friday to inspect the laterals/stand pipe and will provide updates then.
 
As a side note. I just broke a lateral (stupidly) and decided to replace the sand since it is all coming out anway. Depot, Lowes and some Ace products are carrying Pool Filter Sand. The bags had no real information on them other than they are pool sand. I went to their web site and I noticed that the data sheet(s) were described as being ranged between #20 - #40 (HTH is #20).

Depot and Lowes carry Quikrete Pool Filter Sand which is 20/40. Ace was able to order HTH for me.
 
Last edited:
Just a few updates...I decided to remove the sand and inspect the laterals. The sand level seemed fine and I haven’t noticed sand in the backwash or anywhere else. I’ve attached a pic of the sand level before I emptied it. I found one lateral with a very small hole (pic attached). I replaced the lateral and put 300 pounds of new sand from the pool store. This was done Friday and the pump has been running 23 hours per day. It’s now Sunday and the water clarity hasn’t changed a bit. I feel like I should be see some slight changes but nothing so far. Maybe I need to be more patient? How long does it typically take to see changes with a sand filter? I’m used to dealing with algae where the water would clear quickly, so this is different to me.

FC: 15
CC: 0
PH: 7.5
TA: 80
CH: 50
CYA: 70
 

Attachments

  • 2553F544-BD41-4B15-98F6-EB5D56785A32.jpeg
    2553F544-BD41-4B15-98F6-EB5D56785A32.jpeg
    352.1 KB · Views: 8
  • 33AC1C46-CA93-4DA0-B0DF-25936CB3516E.jpeg
    33AC1C46-CA93-4DA0-B0DF-25936CB3516E.jpeg
    234.7 KB · Views: 8
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.