Slamming AGP with 10% bleach and 0 CYA

[path331]

I live in Alabama. The pool has been clear all winter. The last few weeks we have been warm and the pool is now green. I want to slam with 10% pool bleach from Walmart. I just tested the CYA and the dot never disappeared. So I'm guessing I have 0 or very little CYA left. Do I need to raise CYA or just slam with bleach until I get the water clear. PH is 7.2. CL is .5. Then raise my CYA to 70-80

 

[Texas Splash]

Do I need to raise CYA or just slam with bleach until I get the water clear.

Hello and welcome to TFP! Yes, definitely add stabilizer now with a target goal of at least 30 ppm for now. That would mean increasing the FC to "12" to perform the SLAM (link below). Once you have passed all 3 SLAM criteria, THEN increase your CYA to 70 to help your SWG work more efficiently. Good luck!

PS ~ Wal-Mart should also have some HTH brand granular stabilizer on the shelf for about $16 or so. Use the sock-soaking method we discuss here at TFP to help is dissolve.

 

[cfherrman]

A slam is done when the water is clear and when the pool passed oclt.

 

[Teald024]

Hello and Welcome to TFP!

Did you have CYA and FC in the pool when you "closed it" for the season? What is your current water temp?

Before you add your CYA, it may be prudent to add some bleach to the pool and test it in 15 minutes to see if any of it held for that time.

 

[Bama Rambler]

As eluded to above, if this water has ever had CYA in it, then assume it's about 10ppm. If it has never had any CYA in it I'd suggest adding enough to get to about 20ppm (or 30ppm), and then SLAM.

 

[path331]

Thank you for your help. Yes, it has had CYA in it from last year. So I will assume it has about 10ppms of CYA. According to Pool Math I will need to add 8oz of granular in a sock to hopefully raise to 30ppm.

 

[Bama Rambler]

IF that's Dichlor, then that sounds about right. I'd probably just use 10ppm as the CYA for the slam and then raise it after you complete the slam. You can use granular CYA or you could chlorinate with tablets until you've added enough to get to your final target.

 

[Teald024]

Thank you for your help. Yes, it has had CYA in it from last year. So I will assume it has about 10ppms of CYA. According to Pool Math I will need to add 8oz of granular in a sock to hopefully raise to 30ppm.

For a 5300 gallon pool, you would want about 14oz (weight) of granular CYA to raise from 10 to 30ppm CYA.

But as previous said, you may want to wait til after the SLAM is done to add the CYA.

 

[path331]

OK guys. Still need help. I added CYA to pool. Below are my numbers. Pool is still light green. This morning FC still 25, CC is 1.5. Does this mean I still have algae or something in the pool. We've been backwashing the filter (2800 GPH). Do you think I might need to change sand or wash sand? This is the 3rd year for the pool and filter. Any suggestions or should I just keep on until water is clear. Never had these problems before. Water usually clears after a few days.

FC 25.5
CC 1
TA 50
CYA 30
PH 7.2

 

[mknauss]

No need to test pH, not accurate with a FC above 10.

Also no need to go to high FC with a CYA of 30. Shock is 12ppm FC.

Keep testing and adding every few hours. Brush, run pump, etc. Go until you meet the three criteria.

Monitor your back pressures on filter and backwash when pressure rises 25% above clean. Algae is not a filtering problem, but a chemistry problem. You may want to plan a deep clean of your filter after the SLAM.

Good luck.

 

[Teald024]

Likely still have algae, although it’s only been a day or two. Have you noticed it improving at all?Are you following the SLAM procedures in Pool School? How often are you testing and dosing? That 25ppm is fairly high for the first morning test. You really don’t need to be that much higher than your recommended FC based on your CYA. What was your target point last night?

If you have a pressure gauge on your filter, you don’t really need to backwash until the pressure goes up 25% above normal (clean) pressure. Sand filter cleans a little better when it’s a bit dirty.

Take a picture standing from the same spot every day and maybe that will be able to show you progress from day to day. Sometimes it’s hard to notice the gradual change as you are staring at it.
Keep up the SLAM procedure, that is the best course of action.

 

[path331]

If I'm understanding you right my FC is really high. Should I not add anymore Liquid Chlorine until it drops under 12? Mknauss you said keep testing and adding. What should I be adding? If my FC is so high should I wait until it goes down? Sorry for being such a pain but I really want to learn from this experience.

 

[Teald024]

Just test every couple of hours. When FC gets below 12, then you can add more chlorine. No need to add chlorine until then.
Brush often. Run pump constantly.
Nothing else needs to go into the pool

 

[mknauss]

I want to confirm your FC testing process. You used a 10 ml sample of pool water. You then added 2 scoops of DPD powder. You then used 51 drops of reagent to go from pink to clear?

 

[path331]

Mknauss according to my instructions on TF-100 I put 1 scoop of R-0870 then swirled it around. I then added 51 drops of R-0871 to get it to
clear. Multiplied 51x.0.5. Its raining here now so I'm hoping the rain will delute my chlorine a bit. When it quits I will go test again and report the results.

 

[mknauss]

Sounds good. I said two scoops as when you get to high FC testing, more powder may be needed.

Be sure you are swirling the vial while putting in the drops. That is what makes the Speedstir so great!

I just wanted to be sure on the drops. You may consider ordering a FAS-DPD refill as your test reagents are going to go quickly with high FC.

 

[path331]

I just retested FC and CC. FC is coming down a little 22ppm and CC is 0. Pool still light green. My husband is fixing to backwash so I hope this will help. Thanks for putting up with me until I get this problem cleared.

 

[cfherrman]

Stay the course, make sure you are brushing the whole pool

 

[path331]

Update: Water still a very light green. Still checking FC its been over 12 until this afternoon. Sun was shinning most of the day. FC fell to 9.5. I put in 19oz 10% bleach to raise to 12 per CYA at 30. We decided to replace filter sand so I'm hoping we will have clear water within the next few days. Thanks for all your help!!!

 

[mknauss]

Algae in a pool is not a filtering problem, it is a chemistry problem.

Sand has been around millions of years, there is no way you have done anything to it.

Now if you have used pool store potions that have it all gummed up, that is another story.

Good luck.