Green Pool - High Phosphate Level

[Tom Tank]

Bought a home with inground vinyl pool - my first pool ever!. Replaced the liner and everything was fine until we had some soaking rain for three days. I saw this forum and now looking to convert from using 3" pucks and shocking weekly to TFPC. I ordered the TF100 and waiting for it to arrive. After the rain, pool turned a slight greenish color. I could still see the bottom, but not very clear. I shocked it with what I thought was the appropriate level of liquid bleach (4 gallons) and pool is still green. Went to pool store today and they indicated my phosphate levels were high and was the cause of the algae/green color. After reading pool school and looking at my test results below from the pool store, I believe I need almost 6 gallons to shock the pool based on my CYA level. Can someone just confirm that this is the right path? I have a 22200 gallon inground vinyl pool.
Here are my test results...
FC= 5
TC=5
CH-200
CYA-60
TA-80
ph-7.4
Copper - 0
Iron - 0
Total Dissolved Solids - 800
Phosphates - 1000 (the recommendation from pool store is below 100)

 

[jblizzle]

Welcome to TFP!!!

Can you add a little more info to your location? I have no idea where that is.

So, you have seen Pool School, that is good. Have you read the ABCs of Water Chemistry?

We do not "shock" our pools. We follow the ShockLevelAndMAINTAIN Process which requires you to maintain the FC at the shock level until you pass 3 criteria to stop. In order to test these high FC levels, you must have one of the Recommended Test Kits with the FAS-DPD chlorine test ... this is a great investment to cut the cord from the pool store who are trying to sell you useless chemicals, like reducing the phosphates which are meaningless in a properly chlorinated pool.

 

[Tom Tank]

I live outside Raleigh, NC. I am familiar with the SLAM process which I cant really do until I have the TF 100 that I ordered today. So, if the test results above are correct, should I try to reduce the phosphates or SLAM?

 

[jblizzle]

We ignore phosphates. You need to SLAM.

 

[Tom Tank]

That is what I thought. Thanks for the quick reply. Can I just stop using the chlorinator with the tri pucks completely and start the TFPC approach? Or is do I need to do something to get started? Just a newbie and not 100% sure how to get started.

 

[jblizzle]

Definitely stop using tablets before your CYA gets any higher ... might already be too high. Just start and stick with liquid chlorine.

 

[Tom Tank]

Thanks for your help!

 

[tim5055]

Seeing that the TF-100 is shipped from Raleigh I would assume you will see it quickly.

Welcome!!

 

[S4cruiser]

I'm in Durham and i bet the same store that preached to you about phosphates is the one that preached to me. I think mine are in the 2ks but I've ignored them, kept my FC in the appropriate range based on my CYA and water stays clear day in day out!! Cheers to the TFPC!!!

 

[Tom Tank]

I got my TF 100 test kit today and FC= 30 and when I went to do the CC test it = 0. In addition, my CYA = 100!!! Here are two additional questions: 1.) Is it possible to have such a high CYA when I have only been using tri pucks about since beginning of May? 2) When I tested for CC, the water was clear. However, by the time i finished testing for CYA, the tube was a light pink? How long do you wait for the pink color to appear when doing the CC test? From the looks of it, i need to drain 50% of my pool to get back down to an acceptable CYA level. I can't believe using tri pucks for three months (3-5 a week) would cause the CYA to sky rocket like that.

 

[jblizzle]

1) It is possible. How many did you use? Are you sure the CYA was 0 to start with?
In your pool, each 8oz tablet of trichlor would add 2.5ppm FC and 1.5ppm CYA. So 3-5 tablets for 12 weeks, would be 36-60 tablets. Which would have added 54-90 ppm of CYA. And if you used any dichlor powder, that would have added more. And I am not sure if you started at 0 to begin with.

2) You do the FAS-DPD test fairly quickly. Count FC drops to turn clear. Then add the 5 drops for the CC test. Then count the CC drops until clear. You are done. If you leave it sit, it will turn pink again which is meaningless.

 

[jcowart]

Very possible with pucks and weekly shock. For your pool size one 8 oz puck adds 1.5ppm cya. A 25# bucket adds 75ppm. The test only goes up to 100. CYA is only in pool water. Next time mix the test again. 7ml of water and 7ml of regent and shake it up, then pour out 7ml of the mix and replace it with 7ml of tap water. Then run the test and multiply by 2. It could very well be above 100.

 

[jblizzle]

Very possible with pucks and weekly shock. For your pool size one 8 oz puck adds 1.5ppm cya. A 25# bucket adds 75ppm. The test only goes up to 100. CYA is only in pool water. Next time mix the test again. 7ml of water and 7ml of regent and shake it up, then pour out 7ml of the mix and replace it with 7ml of tap water. Then run the test and multiply by 2. It could very well be above 100.

Usually better to start with a 50/50 mix of pool and tap water and then add the reagent. If the CYA is very high, the 7ml of reagent may not be enough to react with all the CYA in the sample and cause bad results.

 

[jcowart]

Usually better to start with a 50/50 mix of pool and tap water and then add the reagent. If the CYA is very high, the 7ml of reagent may not be enough to react with all the CYA in the sample and cause bad results.

My bad... never had to deal with high CYA. I assumed that if you ran the test and got 100 you could just mix it 50/50 and multiply by 2. Still learning new stuff everyday. OP, do what jblizzle said. It could be higher than 100 if you added any during startup and added a lot of dichlor or trichlor shock.

 

[jblizzle]

It should work as you describe if the CYA is not WAY too high, but better safe than sorry

 

[tim5055]

You just don't want to see 100 again

 

[Tom Tank]

Another question I failed to ask is how could my FC=30, CC=0, but the pool is still green and cloudy? I put in the recommended amount of bleach last night based on the pool stores test of CYA=60. I do not know if it FC held because i did not get my test kit until today. However, would there be some CC in the pool by now (3pm over 18 hours later?).

 

[jblizzle]

CC does not always show up in the water just due to algae.

 

[Tom Tank]

I am just confused on how the CC does not show up. I never saw that anywhere in the articles i read. In any case, i just tested again and have the exact same results from 2pm. FC=30 and CC=0. With my CYA level of 100, I need to raise the FC to 39. Should I do that? I would hate to drain half my pool to get the CYA down. Any thoughts or suggestions? Thanks.

 

[jblizzle]

2 options:
1. Replace the water to lower the CYA and make your SLAM and maintenance easier
2. Live the the high CYA, resulting in high shock levels, high FC maintenance levels (>7ppm) and not be able to test the pH when the FC > 10ppm