Salt Water Shock. I'm stuck mid process.

[Pezman]

Hello,

I am a long-time reader here. After two years of owning a saltwater pool, I returned from vacation to algae. I tried to fix it, but now I'm unsure how to resolve my mistake.

What I did so far:

1. Returned from vacation and saw algae under Solar cover
2. Vacuumed Algae
3. Balanced Alkalinity
4. Balanced PH
5. Chlorine was very low (0.4ppm)
6. Added 3/4 a bag of "Regal Dy-Chlor II" in an attempt to stablize Chlorine before adding shock
7. Now I'm way above 2 ppm, I'm at 6!
8. Still trying to figure out what to do next.

Pool Details:

• Pool: Intex 24x12x52 Ultra XTR Saltwater.
• Gallons: 8,400
• Pump: QX 2100 /w boost
• Setup in Colorado, Air temp ~100 mid day
• Pool Temp ~83

Chemistry Details (at this moment in the messed up status):

• Kit: Taylor K-2006-SALT
• Free Chlorine: 6ppm! (Before adding 3/4 bag of Regal Dy-Chlor II it was 0.4)
  • Based upon forums I believe I need: 1-3ppm
• Combined Chlorine: 0.2ppm
• pH: 7.8
  • Targeting: 7.5
• Alkalinity: 110
  • Targeting: 100-150
• Stabilizer (CYA): 30
  • Targeting: 80
• Calcium Hardness: 120
  • Targeting: 150-250
• Sodium Chloride: 2,000
  • Targeting: 2,500-3,000

There you have it. What should I do to?

I'm primarily unclear if my Chlorine is supposed to spike before I add "Shock" or if I need to uncover and add peroxide or something to reduce Chlorine before proceeding with Shock to clear the water up.

TL;DR: I had Algae in my Saltwater pool, and I attempted to fix it. However, I am unclear on the next step since I made a mistake. Send help.

 

[Rancho Cost-a-Lotta]

To get rid of algae, you need to complete the SLAM Process. You'll need to maintain FC based on your CYA level. With a CYA of 30 ppm, you'll need to maintain FC at 12 ppm. The best way to do that is to use liquid chlorine. Trying to maintain FC levels with granular or solid forms of chlorine is too difficult.

Read the article on the slam process several times to make sure you completely understand it. Realize this is a process and not a one-time thing. It may take several days or even weeks to completely get rid of the algae.

 

[PoolStored]

Do not raise your CYA until you complete the SLAM process. Link-->SLAM Process

 

[JJ_Tex]

The worst thing you could do is lower your chlorine. Take a deep breath and keep in mind these key points:

• You have algae because your chlorine was too low
• Your chlorine of 6 is not high at all. Ignore other websites that make a blanket statement about chlorine needing to be 1-3, or some now say 1-5. That logic is from the 1950's when pools did not have CYA in them to buffer chlorine. Here at TFP, we look at FC and CYA as a ratio.
• To kill all of your algae, you need to follow the SLAM process which was posted above.
  • Read the SLAM process
  • Read it again and write down any supplies you need, probably liquid chlorine and some initial MA to lower your pH
  • Go buy said supplies (Walmart, Home Depot, Lowes are much better than the pool store)
  • Read the article one more time
  • Start the SLAM... it will take several days but you will have a crystal clear and healthy pool

 

[Pezman]

Ah, yes, SLAM. For some reason, I thought it was for non-SWG pools. Thanks for clarifying it will work. I downloaded the Pool Math app and will see how to load my info instead of using a Google Sheet for logging tests.

Based on the SLAM process, I'll double-check that my CYA is still 30 and, if not, get it there first. Then, I'll Lower my pH further and start adding the liquid Chlorine. I opted for the "Pool Essentials Chlorinating Liquid." From what I can see on other posts, it should be good. Do let me know if I've misstepped.

 

[Rancho Cost-a-Lotta]

Do let me know if I've misstepped.

Great plan. Keep us posted and let us know if you need help.

 

[Pezman]

An Update for Posterity!

If you're a newbie like me, here are some things I've noticed as a first-time SLAMer:

1. The documentation tells you to calculate how much liquid chlorine you need using the Pool Math app. However, this isn’t super intuitive in the app. It would be fantastic if the app had a more user-friendly calculator for this purpose. I'm not complaining, just sharing that it wasn't clear how to bring together disparate data to figure out the number of gallons needed. I ended up guessing poorly and had to make a trip back to Walmart after four days.
2. I discovered that using a pool filter sock can be helpful when vacuuming, so I’m giving that a try. Each day, I vacuum and scrub the walls, floor, and skimmer with a brush (I've removed the ladder). I’m not sure if this is necessary, but my pump hasn’t needed backwashing, even though I do it once a day. Also, vacuuming without some type of fine net seems ineffective.
3. Make sure you have enough testing chemicals. Oh boy, I have a Taylor 2006 kit, you'll need more than you thought, especially if you plan to test FC every 2-4 hours during the day.

After five days, I'm still not at the finish line. The water is less green but still cloudy. At my current pace, I presume I have another four days to go, but that’s just speculation.

 

[dereksanders]

Since you took the ladder out, disassemble it as much as you can and thoroughly clean/disinfect it to rid it of residual algae. You’ll be surprised at what it hides.

 

[Pezman]

Another update.

It took ten days, but my sand filter finally did the job. I only lost a little less than 1 ppm of FC last night. I'm thankful for this as I've been burning through liquid chlorine. Per the instructions, I've not been running the SWG, just leaving the pump running 24/7 without it.

From what I can tell, the documentation doesn't provide guidance on how best to "return to normal." Is there a suggested method any of you follow? Specifically, how should I reduce FC from 30 ppm back down to something like 3 ppm? Do I descend gradually? Just shut the pump off and let the sun bake the chlorine off? Only turn the SWG back on once I get to ~3 ppm?

Sorry if I'm being dense.

 

[ajw22]

From what I can tell, the documentation doesn't provide guidance on how best to "return to normal." Is there a suggested method any of you follow? Specifically, how should I reduce FC from 30 ppm back down to something like 3 ppm? Do I descend gradually? Just shut the pump off and let the sun bake the chlorine off? Only turn the SWG back on once I get to ~3 ppm?

Keep the pump running for filtering and water circulation.

Just stop adding liquid chlorine and the sun will reduce your FC.

Before your FC gets to your desired FC level, which I doubt is 3PPM, turn your SWG on.

With a CYA of 50 you want FC of 6-7PPM.

Turn on your SWG by 10ppm and just set the % to be a bit less then what is needed to slowly drop to 7ppm.

 

[JJ_Tex]

And make sure you pass all 3 criteria to exit a SLAM. When I hear things like "I only lost a little less than 1 FC last night" means you barely passed that single test. I would hate to see you get back down to normal and start having algae re-appear and you have to start all over.

Speaking of algae re-appearing, please don't go back to flirting with the 3 FC minimum. Keep that sucker at the upper end of your target range. I have the same CYA as you and look at the chlorine in my avatar. I start getting nervous if I'm even close to 5 FC.

 

[dereksanders]

And make sure you pass all 3 criteria to exit a SLAM. When I hear things like "I only lost a little less than 1 FC last night" means you barely passed that single test. I would hate to see you get back down to normal and start having algae re-appear and you have to start all over.

Speaking of algae re-appearing, please don't go back to flirting with the 3 FC minimum. Keep that sucker at the upper end of your target range. I have the same CYA as you and look at the chlorine in my avatar. I start getting nervous if I'm even close to 5 FC.

Amen. If you’re not checking FC at least thrice a day don’t flirt with the low end.