Our pool is green and pool store says to replace sand
- Thread starter Smileysjs
- Start date
mguzzy
Gold Supporter
OK.. now that you got your chem numbers back in line lets start the SLAM Process to kill the Algae and get your pool crystal clear. I re quoted Zea's post so you know where we are in the process. Add some more MA to get the pH down to 7.2 and start SLAMing away. A SLAM takes a few days depending on how bad the algae is so be patient. The more diligent you are with brushing the nooks and crannies will help the process along. Trust us, you husband will be impressed with the final outcome.
You are ready to start your slam! You will need a lot of liquid chlorine. The 10% from Walmart is usually a good value, but any liquid chlorine will work. You can use PoolMath (there is a link to the web based pool math at the bottom of the page) to help you determine how much chlorine to use to bring the pool to slam (or shock) level. Bring the pool to slam level and keep the pump running. Test the FC an hour after you brought it to slam level, and add more FC to bring it back up as needed. The first day or two of a slam you will usually be adding chlorine pretty frequently to keep it at slam levels. When the chlorine loss drops to 2-3 ppm between additions you can test less frequently. Don't worry about any other tests while you are slamming the pool. Once the slam is completed you can re-balance the pool if needed. The only thing you need to add now is liquid chlorine. No dry chlorine products allowed!
Just go slow. You overdid the baking soda a bit. Now that the numbers are in the correct range, follow the SLAM process (it’s a process) and ask questions, and keep posting results. Chlorine is what gets rid of green pool. So you’ll be adding a lot of it.
After your slam is done we can look at those options. Neither will help during a slam.
Yes, you can change to a SWG. But not yet. SWGs are really good at maintaining chlorine, but no good at making a lot quickly. What you need right now is a lot of chlorine in relatively short time. As your water has algae, some of the algae and the chlorine kill each other, and then the rest of the algae keep right on multiplying - unless you get your chlorine level high enough, and keep it there long enough, to outpace the algae reproduction.
Once you no longer have large amounts of algae in the water consuming your chlorine, an SWG will do a great job of keeping up with the little bit of chlorine consumed by UV and normal conditions (bathers, pollen, etc).
Take photos of your pool, now (start) and periodically throughout the SLAM process. It's normal for it to go from dark green, to light green, to bluish white within a couple days. Then the white cloudiness will clear, very slowly, as your filter removes the dead algae. Photos help to look back on and see the daily process. I also measured visible depth - at first I could only see 3 inches of the vacuum pole, then I could see a foot, then I could see two feet, etc.
Once you no longer have large amounts of algae in the water consuming your chlorine, an SWG will do a great job of keeping up with the little bit of chlorine consumed by UV and normal conditions (bathers, pollen, etc).
Take photos of your pool, now (start) and periodically throughout the SLAM process. It's normal for it to go from dark green, to light green, to bluish white within a couple days. Then the white cloudiness will clear, very slowly, as your filter removes the dead algae. Photos help to look back on and see the daily process. I also measured visible depth - at first I could only see 3 inches of the vacuum pole, then I could see a foot, then I could see two feet, etc.
It’s at 13tc and I’ve just added another 94oz bleach. Set the timer for another hour. Still green with a few tiny bubbles. Pool vacuum is going and I just brushed it.
So this time I only got 11tc. So it went down two in one hour.
mguzzy
Gold Supporter
Yup, that is the chlorine killing off the algae.. As that happens your CC should be rising. what was your CC reading? Isn't this fun!
No ccYup, that is the chlorine killing off the algae.. As that happens your CC should be rising. what was your CC reading? Isn't this fun!
Tested again. it’s at 14.5 tc no cc.
- May 3, 2014
- 62,708
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
No real reason to test CC. It will typically be 0 or close to it if sun is shining on the pool. Do the CC test the morning of the OCLT to check for completion of SLAM.
Make sure you’re testing the right things:
FC = free chlorine, the stuff that’s cleaning the water
CC= combined Chlorine/chloramines, the bad stuff
TC = total chlorine, a math expression of FC+CC=TC. Generally a useless number if you are testing FC and CC separately anyway. You can ignore TC with a Taylor kit.
- Jul 9, 2016
- 227
- Pool Size
- 24000
- Surface
- Vinyl
- Chlorine
- Salt Water Generator
- SWG Type
- Pureline Crystal Pure 60,000
I've been following your thread. Just wanted to make sure you keep an eye on the pressure gauge on your sand filter. The filter pressures can rise quickly during a slam and may require frequent backwash cycles depending on how high your algae load is. First, make sure your pressure gauge is working, if it does not return to zero when the pump is off then it should be replaced. The gauge itself is usually inexpensive and easy to replace, I usually have to replace mine every couple of years. I'm currently on day four of my slam, my pool was VERY green (swamp) and full of tadpoles and frogs. I'm having to backwash mine every three hours or so. My pressures go from 19 right after a backwash to 25 in about three hours. As the sand gets full of organics it decreased your waterflow through the filter which greatly slows down the progress of your SLAM.
- Jul 9, 2016
- 227
- Pool Size
- 24000
- Surface
- Vinyl
- Chlorine
- Salt Water Generator
- SWG Type
- Pureline Crystal Pure 60,000
Every time you test, you should add enough chlorine to bring it back up to your SLAM level. You can test less often as your chlorine demands slow down during the process.
I backwashed this morning before I started adding bleach. The pressure is 35-40. Didn’t think to look to see if it goes to 0 when I turn it off.
You do want to keep the FC up, however if you are only losing 1-2 ppm in an hour's time, you can wait a little longer to bump it up. The FC is still working, we just don't want it dropping from 16 to 4 in an hour.
Check the pressure gage next time you go out to add chlorine. Turn off the pump and see if the gauge goes to zero. It is pretty easy to swap out if the gauge is broken.
Check the pressure gage next time you go out to add chlorine. Turn off the pump and see if the gauge goes to zero. It is pretty easy to swap out if the gauge is broken.
- Jul 9, 2016
- 227
- Pool Size
- 24000
- Surface
- Vinyl
- Chlorine
- Salt Water Generator
- SWG Type
- Pureline Crystal Pure 60,000
I've got my eyeball jets set so that they lightly ripple the surface of the water, when the sand filter needs backwashing the pressure from the returns is so low that I can not see any movement on the surface. I use that as a quick visual clue to go check my pressure and backwash.