We have a 3700 gal above ground pool with a newly installed Intex QX2100 Krystal Clear Sand Filter Pump and Saltwater System. We switched from the Intex cylinder paper cartridge filter that came with the pool because we just could not clear an algae bloom. Once the sand filter was installed, we were able to clear the bloom in about two weeks using SLAM. A few weeks later the pool deck was stained by a contractor using a Bahr water based stain. Since the stain I have been changing the skimmer sock twice a day as it gathers stain colored scum, and last night I vacuumed to get any larger tendrils. It has been 3 days since staining and i decided to backwash as water pressure seemed low. Mistake. I am now getting a 90 error code which the manual says could mean circulation line block. I backwashed and rinsed 4 times @30 seconds each time and while the flow looks better in the pool, the filter keeps yelling and flashing 90. Is this a contractor issue or just coincidental timing? Advice?
Sand Filter clog after deck stain?
- Thread starter vickiann
- Start date
- Jun 22, 2014
- 52,045
- Pool Size
- 17888
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
Welcome to TFP! 
It sounds like you may have two problems - one compounded by the other. First you had algae and I"m not so sure you ever really completed the SLAM Process properly. Do you have a TF-100, Pro-Series ,or Taylor K-200C test kit? You would need one of those and perform the SLAM until you passed all 3 criteria. So that was issue #1.
The second of course is the stain. Possibly a bit gummy and could've coagulated within the filter quickly, especially if the filter was already overwhelmed from organics.
So let's start with a full set of water test results from one of those kits. That would be step one. In the meantime, try running the filter on recirculate just so you can keep the water moving and chlorinated. If needed, add some liquid chlorine as well.
It sounds like you may have two problems - one compounded by the other. First you had algae and I"m not so sure you ever really completed the SLAM Process properly. Do you have a TF-100, Pro-Series ,or Taylor K-200C test kit? You would need one of those and perform the SLAM until you passed all 3 criteria. So that was issue #1.The second of course is the stain. Possibly a bit gummy and could've coagulated within the filter quickly, especially if the filter was already overwhelmed from organics.
So let's start with a full set of water test results from one of those kits. That would be step one. In the meantime, try running the filter on recirculate just so you can keep the water moving and chlorinated. If needed, add some liquid chlorine as well.
Thank you! You read and read but nothing beats talking with someone who is experienced! So I am not sure I completed the SLAM process completely either. Especially as the pool is now cloudy and a light teal color after just 12 hours with the filter off (it had been pretty clear). The filter seems to be mostly working again. The inflow is reduced and appears to be gradually decreasing (kids have been in pool for about an hour). It will likely need a backwash by this afternoon. I bit the bullet and ordered the TF-100. For the moment I'm depending on (nooooo) the pool store results. Will go again today if it's helpful. Last results were from 6 days ago. Don't know they will be of any help at all. Since then i've added about 400 gallons of water (well water - at least half softened), and 10 cups salt, and (when the kids get out in a bit) a gallon liquid bleach. Our pool is partially shadowed at least half of the day by live oaks and we are on a marsh - so we get debris. We use a skimmer with a sock, I vacuum and scrub once a week and have run the sand filter 24/7 since we installed it.
FC 4.26
TC 4.26
ph 7.7
alk 137
adj alk 95
calcium 32
CA 141
iron 0
copper 0
phosphate 258
salt 2625
saturation index neg .72
FC 4.26
TC 4.26
ph 7.7
alk 137
adj alk 95
calcium 32
CA 141
iron 0
copper 0
phosphate 258
salt 2625
saturation index neg .72
- Jun 22, 2014
- 52,045
- Pool Size
- 17888
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
The pool store testing isn't any help, so don't worry about it just yet. Until your TF-100 arrives (nice choice by the way), just add about 1-2 cups of liquid chlorine to the water each day to help the SWG and the cloudiness. Once your kit arrives, post those numbers and we'll get very accurate with the next steps. Don't worry, we have your back. 
- Jun 22, 2014
- 52,045
- Pool Size
- 17888
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
Also, don't forget to update your signature! 
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- Jun 1, 2018
- 16,027
- Pool Size
- 26000
- Surface
- Vinyl
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
Looking forward to seeing your results!
For the stain, Keep changing the skimmer sock & you may want to look into the disposable hairnets that many of us use.
In the future be sure to cover the pool when spraying/staining. I do mine when the pool is closed - early spring or late fall.
Same goes for if you need to paint anything in the vicinity- sprayed particles can really travel!
For the stain, Keep changing the skimmer sock & you may want to look into the disposable hairnets that many of us use.
In the future be sure to cover the pool when spraying/staining. I do mine when the pool is closed - early spring or late fall.
Same goes for if you need to paint anything in the vicinity- sprayed particles can really travel!
Hello again - I have a test kits and results! The pool company lady freaked (seriously freaked - DONT GET IN THE WATER!) when she tested. The next day I used my newly arrived test kit and I saw nothing to freak about. Interested to see what you guys think. TF-100 results:
FC 22.4 ph 8.5 TA 140 CYA 95 CH 75 Salt 2600 temp 85
Side note - live oaks above the pool so shaded after 3pm. Tree debris and a lot of pollen. Also getting a lot of rain right now. SWG and filter system seem to be doing well, but pool continues to have difficulty. Finally cleared the green tinge but cloudiness varies daily and we continue to have what I think is pollen (Silky clouds of brown yellow in wave patterns every couple of feet on the bottom, puff into the water when brushed or kicked.) Brushing daily. SWG set to generate for 15 hours with filter 24/7. I was adding chlorine daily but quit when the pool lady freaked. (I may have overdone the chlorine but she gave a Scream Queen performance. And of course wanted me to buy various chemicals.)
FC 22.4 ph 8.5 TA 140 CYA 95 CH 75 Salt 2600 temp 85
Side note - live oaks above the pool so shaded after 3pm. Tree debris and a lot of pollen. Also getting a lot of rain right now. SWG and filter system seem to be doing well, but pool continues to have difficulty. Finally cleared the green tinge but cloudiness varies daily and we continue to have what I think is pollen (Silky clouds of brown yellow in wave patterns every couple of feet on the bottom, puff into the water when brushed or kicked.) Brushing daily. SWG set to generate for 15 hours with filter 24/7. I was adding chlorine daily but quit when the pool lady freaked. (I may have overdone the chlorine but she gave a Scream Queen performance. And of course wanted me to buy various chemicals.)
- Jun 22, 2014
- 52,045
- Pool Size
- 17888
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
Nice to see you have a good test kit. Ideally, it would be good to exchange some water to bring that CYA down a bit. 70 would be a good CYA and requires less chlorine during the SLAM Process. You can't trust that pH result right now because you FC is well over 10.
So do you think you can exchange some water first?
Ideally, it would be good to exchange some water to bring that CYA down a bit. 70 would be a good CYA and requires less chlorine during the SLAM Process. You can't trust that pH result right now because you FC is well over 10.So do you think you can exchange some water first?
- Jun 22, 2014
- 52,045
- Pool Size
- 17888
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
For FC testing, be sure to use a 10 ml water sample with one generous scoop of power. Mix and add drops until clear and divide in half. Example, 40 drops to clear equals an FC of 20.
Hello and thank you! So - I admit it is not my FC result. My kit did not have the powder it needs and Nate said it is now on its way. So I used the pool store's reading. It is likely true as the square PH and chlorine color box from the kit shows the chlorine as orange. It was orange in pm a few days ago and turning yellow by the am so I assumed it was fighting something. It has held orange for two days and the green pool water is gone but the water is moderately cloudy. I will backwash today. Would a minute of Backwash and a minute of Rinse do enough? (So in April pool store said CYA was 140 - it's improving)
Also it has poured rain in the three days since testing which may impact current CYA
- Jun 22, 2014
- 52,045
- Pool Size
- 17888
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
That can vary. A backwash might take 1-2 minutes followed by a thorough rinse of about 30 sec to a minute or so. For rinse, once the waste line (or sight glass) is showing clear water, give it another 20-30 seconds.
- Jun 22, 2014
- 52,045
- Pool Size
- 17888
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
Not unless you overflowed and had to lose/exchange water. Simply getting rain won't change it. CYA does not dilute.
sktn77a
Gold Supporter
Well, it does dilute but probably not enough to make a measurable difference from one rainfall.
Typical Georgia rain will make a dent in an Intex pool. I'm assuming with so little gallons it's a 30 inch, but even if it's a 42, they get over 4 ft of rain annually on the coast. That's a free water exchange or more, a couple inches at a time.
It varies with the weather patterns so it may seem like a never ending chore at some times, then level off for a while, but given a couple of months, it'll almost always add up.
For sand pools the backwashing lowers the couple of inches the pool is always gaining so it probably doesnt seem like excessive 'overflow' for them. Cartridge pools will drain an inch or two here specifically because the water level is raised from the storms so they might recognize that they've actively been lowering the pool sooner.
Southeast inground pools will see more drop than most of the country also, but with more depth than above grounds, 2 inches at a time matters proportionally less.
It varies with the weather patterns so it may seem like a never ending chore at some times, then level off for a while, but given a couple of months, it'll almost always add up.
For sand pools the backwashing lowers the couple of inches the pool is always gaining so it probably doesnt seem like excessive 'overflow' for them. Cartridge pools will drain an inch or two here specifically because the water level is raised from the storms so they might recognize that they've actively been lowering the pool sooner.
Southeast inground pools will see more drop than most of the country also, but with more depth than above grounds, 2 inches at a time matters proportionally less.
sktn77a
Gold Supporter
Bottom line, though, is your CYA is high. Water replacement is the only practical solution. Get it down to 50-70 for a SWG.