Blue clear water, but green stains inside pool

[gdog2004]

Hi guys:
I have a TF-100 test kit. Here are my reading...

FC-4.0
PH-7.6
TA-60
CYA-less than 20 (black dot does not disappear completely)
Water Temp -87 degrees

My water is pretty blue and clear however I have these green stains along the vinyl liner in multiple spots that are hard to remove. They are very faint green.
I vacuumed and back washed and rinsed my sand filter.
I am assuming this is some form of Algae ?
I am prepared to SLAM if needed. I know I need more CYA but don't want to wait days for it to dissolve in skimmer sock (seems to take days)
As you can see my pool is pretty blue, the stains are hard to see.
Thank you all in advance for your advice.
On a side note, I am awaiting my Dolphin S200 so I hopefully don't have to vacuum anymore.
Also, if the CYA is less than 20, what is the harm in starting slam now ? I understand it has to be raised, but not sure why it needs to be prior to slam.

 

[gdog2004]

Updating on test results...

FC-4.0
CC-0.00 mayybbbeee .5 --slightly unclear..
PH-7.6
TA-60
CYA-less than 20 (black dot does not disappear completely)
Water Temp -87 degrees

 

[Texas Splash]

Gdog, it's hard for me to see the stain clearly, but if you're sure it's algae, then yes - SLAM now. Follow the SLAM Process instructions carefully using your TF-100. Now if you are on a well or known to have iron in your local water, try rubbing a Vitamin C tablet on that area first. Just a shot in the dark. But if there's no reaction, it's probably algae. It doesn't take weeks for the stabilizer to dissolve. Place the required amount in a sock or nylon, give it about 15-20 minutes to get soggy, then squeeze often. Once it's dissolved, consider the new CYA target reached. Use the PoolMath tool. You need a CYA of 30 so that you can SLAM at an FC of 12. Don't forget to lower the pH to 7.2 before increasing the FC to 12. Good luck!

 

[gdog2004]

Gdog, it's hard for me to see the stain clearly, but if you're sure it's algae, then yes - SLAM now. Follow the SLAM Process instructions carefully using your TF-100. Now if you are on a well or known to have iron in your local water, try rubbing a Vitamin C tablet on that area first. Just a shot in the dark. But if there's no reaction, it's probably algae. It doesn't take weeks for the stabilizer to dissolve. Place the required amount in a sock or nylon, give it about 15-20 minutes to get soggy, then squeeze often. Once it's dissolved, consider the new CYA target reached. Use the PoolMath tool. You need a CYA of 30 so that you can SLAM at an FC of 12. Don't forget to lower the pH to 7.2 before increasing the FC to 12. Good luck!

Thanks Texas! My local water does have iron however, the only water that has ever gone into the pool is water from a truck and rain water.
What do you mean by a vitamin C tablet ? Cant I slam with a CYA less than 20 or even a CYA of 10 or less ?
I am home and can monitor it. Also...can I swim while slamming ? Underwater ?

 

[Texas Splash]

What do you mean by a vitamin C tablet ? Cant I slam with a CYA less than 20 or even a CYA of 10 or less ?

We use Vitamin C tablets as a way to test staining for iron. You can take a tablet and rub it on the stain to see if it lifts it (iron). Of course if there is no change, it's probably what you assume to be an organic stain from algae. But may be good to confirm.

As for the CYA, you do want to ensure you have at least 30 so that you can perform the SLAM Process with an elevated FC level of '12". The CYA viewing tube doesn't give accurate (estimated) results below 30, so trying to estimate an CYA of 20 or 10 is not really feasible. Plus, your chlorine needs the protection a CYA of 30 provides during the SLAM.

During the SLAM, you can swim as long as the FC level does not exceed what it is allowed for the current CYA (see FC/CYA Levels). Many find it easier to get in there and inspect, clean, etc anyways. You may want to rinse-off your swimwear afterwards, but it's totally fine as long as your CYA is 30 and FC does not exceed 12.

 

[gdog2004]

We use Vitamin C tablets as a way to test staining for iron. You can take a tablet and rub it on the stain to see if it lifts it (iron). Of course if there is no change, it's probably what you assume to be an organic stain from algae. But may be good to confirm.

As for the CYA, you do want to ensure you have at least 30 so that you can perform the SLAM Process with an elevated FC level of '12". The CYA viewing tube doesn't give accurate (estimated) results below 30, so trying to estimate an CYA of 20 or 10 is not really feasible. Plus, your chlorine needs the protection a CYA of 30 provides during the SLAM.

During the SLAM, you can swim as long as the FC level does not exceed what it is allowed for the current CYA (see FC/CYA Levels). Many find it easier to get in there and inspect, clean, etc anyways. You may want to rinse-off your swimwear afterwards, but it's totally fine as long as your CYA is 30 and FC does not exceed 12.

OK, I have put granulated stabilizer in a stocking in the skimmer and it did take a few days to dissolve. There has to be a better way than that....is there a brand of Stabilizer that dissolves easier ? Can I put it in a bucket of hot water and dissolve it that way ?

 

[Texas Splash]

I have put granulated stabilizer in a stocking in the skimmer and it did take a few days to dissolve.

It should never take that long. Just last week I placed stabilizer in a regular white tube sock, let it pre-soak for about 15-20 minutes to get all nice & soggy, then I would squeeze often. I can get about 1-2 lbs to dissolve in about 15 minutes once soggy. The only time I had difficulty getting the granules to dissolve quicker was when I used an old batch.

 

[IceShadow]

Squeeze it every few minutes and it goes much faster. I also prefer to hang it in front of a return jet, just in case my pump goes out or something - I don't want acidic water sitting in the skimmer.

There is liquid stabilizer but it is 3-4 times as expensive for the amount you get from granulated.

 

[gdog2004]

It should never take that long. Just last week I placed stabilizer in a regular white tube sock, let it pre-soak for about 15-20 minutes to get all nice & soggy, then I would squeeze often. I can get about 1-2 lbs to dissolve in about 15 minutes once soggy. The only time I had difficulty getting the granules to dissolve quicker was when I used an old batch.

OK, I used the stabilizer that came with my pool. Maybe is was old. I will go buy some new stabilizer from Lowes or amazon. I am assuming something like this is fine.

Amazon.com : Clorox Pool&Spa Chlorine Stabilizer 4 lb : Garden & Outdoor

Amazon.com : Clorox Pool&Spa Chlorine Stabilizer 4 lb : Garden & Outdoor

www.amazon.com

.

 

[Texas Splash]

That's exactly what I use. 100% cyanuric acid.

 

[gdog2004]

That's exactly what I use. 100% cyanuric acid.

OK guys, using the Clorox Stabilizer is MUCH better than the stuff that came with my pool (must have been old...would not dissolve)
I added about 5 lbs of it to bring my CYA up.
Current measurements
CYA 45-50
PH 7.0 (approximately)
TA 50 (approximately--color STARTED to turn very light pink/red at 50 much deeper pink/red at 60)
FC 6.0
CC .5
TC 6.5

Pool is pretty darn clear as you can see but still has light greenish stains at liner seams and a few other spots(some of them do wipe away with a towel).
I received my Dolphin S200. OK to vacuum algae with it ? I can't really vacuum to backwash.
If my pool is this clear...is it really Algae or just dirt ?

 

[ajw22]

Do an Overnight Chlorine Loss Test to determine if you need the SLAM Process.