SLAM ???

Debbie17

Active member
May 18, 2021
29
Middleton, MA
Pool Size
30000
Surface
Vinyl
Chlorine
Liquid Chlorine
Hello! New to TFP, First time pool owner, live in the Northeast, uncovered my green swamp Sunday. vinyl, 18x36, 30,000 Gallons. Prematurely my friend added 4 gallons of chlorine to the water before i had a chance to test after we took the cover off. Couldn’t figure out how to run the equipment until last night. I did take the filter apart yesterday, cleaned the cartridge, put it all back together then added Earth to the skimmer. I vacuumed this morning, skimmed the top and then scrubbed the walls. Same friend stopped by today and added another gallon of chlorine before I tested. So I am ready to start a slam but I don’t know my starting PH because 4 bottles of chlorine was added on Sunday and 1 bottle today.

I busted out my Taylor kit and after watching several YouTube videos I decided to give the FAS-DPD test a try. Here are my results:

FC - 5.8
CC - .2
CYA - I filled the entire tube and could still see the dot. The water was not at all cloudy so not sure how to get that reading.
PH - I gave it a shot anyway but the water was totally yellow so it didn’t match any result on the chart.
TA - I gave up after adding 30 drops and with no changes to the hello color.

I don’t even know where to start at this point since I’ve missed some steps in the SLAM process. Any advice would be greatly appreciated.
 
Welcome to TFP.
Just a couple of points I see
If you did your CYA test correctly then you have ZERO CYA - so maybe that is why your pool is consuming chlorine in addition to the green stuff.
Your FC may or may not be OK. For 30k gals, adding 5 gallons of LC (I assumed 10%) that would increase FC by 17ppm. You are now showing 5.8ppm. So either you have a lot of stuff consuming your FC or you need to redo your FC to confirm.
Also, you should be able to get a good pH test because it is valid up to 10ppm of FC. So if you are really at 5.8ppm then your pH test should be valid. It may be very low, but I would test your FC again (before your neighbor shows up), then if under 10ppm test your pH.
Others will chime in as well but this something to start with.
 
Thank you! It was my first time testing and i was feeling a bit intimidated so maybe i goofed. I watched you tube videos and followed along during my testing so I’m thinking I did them right. The only one I didn’t follow the video while testing was PH. I will retest all the levels tomorrow morning and report back. My filter pressure was getting high this evening so I ended up having to take the filter apart and clean the cartridge again and add earth. It weighed about 100lbs from all of the algae. It was so gross! So I’ll be starting with a clean filter once again.
 
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Thank you! It was my first time testing and i was feeling a bit intimidated so maybe i goofed. I watched you tube videos and followed along during my testing so I’m thinking I did them right. The only one I didn’t follow the video while testing was PH. I will retest all the levels tomorrow morning and report back. My filter pressure was getting high this evening so I ended up having to take the filter apart and clean the cartridge again and add earth. It weighed about 100lbs from all of the algae. It was so gross! So I’ll be starting with a clean filter once again.
Regarding pH testing. You are using the Taylor kit, so you fill the tube to the 44ml mark. I have read in other posts on this forum that some have only put in 4 drops of reagent. Try that and read the result. Then add the 5th drop and see if any change. Remember it is only good to test pH if your FC is under 10ppm.
For reference - I found this pH test using Taylor kit
 
Regarding pH testing. You are using the Taylor kit, so you fill the tube to the 44ml mark. I have read in other posts on this forum that some have only put in 4 drops of reagent. Try that and read the result. Then add the 5th drop and see if any change. Remember it is only good to test pH if your FC is under 10ppm.
For reference - I found this pH test using Taylor kit
Thank you for that video. I did do it wrong. I did not fill to the 44 ml line. I only filled to the 25. 🤦‍♀️ Videos are so helpful!
 
Just completed my tests again.

FC - 0 (water did not turn pink, tested twice to make sure and got the same result).
PH - I’m still not getting a result. I made sure to follow the video. I get a yellow color that does not match the chart. I attached a photo for reference.
CYA - 0 (I could see the black dot)

How do I fix my PH and CYA so I can start a slam? And should I add any chlorine in the meantime? There is still tons of algae in the pool even though it’s better than yesterday. 🤮. I’m planning to vaccum and brush walls when my twins go down for a nap at 11am.
 

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Suggest you add some more chlorine. Also, do you have enough to do a proper SLAM? You will need to get to at least 10ppm. Need to advise us what % Liquid Chlorine you are using. I assumed 10% in my earlier calculation but best to have what you are actually using. Also, do you have any Borax (just the plain stuff you can purchase at grocery store). You may need some to raise pH but the better way is to aerate to raise pH. Do you have any type of water feature or spillover that can cause aeration? That will raise your pH. Right now it is ok to have a lower pH to SLAM. In fact, please read the SLAM Process

I as asking @mknauss or @Texas Splash to chime in on other thoughts.
Also suggest you Create Your Signature to help us understand all of your equipment, do you have a spa, any water features, etc.
All we know now is 30,000gals vinyl, possibly a DE filter. Please update with correct info.
 
@Debbie17 I was reading another post on SLAM and these are the recommendations offered by @Newdude to a similar issue as you have. Hope this helps you understand the process.

Test and add chlorine, at first, every 2 hours is best as it will chew through your FC. After a day or 2, It will hold for 4 hours, then 6..... 8.... 12. The better you Maintain the FC up high, the quicker it goes. (That is why you have to have sufficient LC on hand) Once it’s gets blue and cloudy it’s mostly dead and you still maintain, but the battle shifts from a chemistry fight to a filter it all out fight. You still keep the FC up to not lose any ground, but the babysitting shifts focus to the filter. Backwash/rinse anytime the filter rises 25% of its psi.
 
If the TA test turned yellow, your TA is zero or less. With that and the yellow pH test result, you have vinegar in your pool . You need to aggressively raise the TA and pH NOW. The water is damaging your liner and if you have a heater, it is dissolving it.

Use soda ash. Soda ash is available as ARM & HAMMER® Super Washing Soda Detergent Booster. Do not confuse this with ARM & HAMMER® laundry detergent! It is sold in the laundry detergent section of most larger grocery stores and some big box stores. It is also sold by pool stores under various names, including PH Increaser, PH Up, Balance Pak 200, etc. Soda ash is best added by pre-dissolving it in a bucket of water and then pouring that slowly in front of a return.

Use Poolmath. I would suggest adding 5 pounds, circulate well, test TA again, if still yellow, add another 5 pounds.
 
If the TA test turned yellow, your TA is zero or less. With that and the yellow pH test result, you have vinegar in your pool . You need to aggressively raise the TA and pH NOW. The water is damaging your liner and if you have a heater, it is dissolving it.

Use soda ash. Soda ash is available as ARM & HAMMER® Super Washing Soda Detergent Booster. Do not confuse this with ARM & HAMMER® laundry detergent! It is sold in the laundry detergent section of most larger grocery stores and some big box stores. It is also sold by pool stores under various names, including PH Increaser, PH Up, Balance Pak 200, etc. Soda ash is best added by pre-dissolving it in a bucket of water and then pouring that slowly in front of a return.

Use Poolmath. I would suggest adding 5 pounds, circulate well, test TA again, if still yellow, add another 5 pounds.
It was my PH test that turned yellow. I did not do a TA test but will do that shortly to see what result I get.
 

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Suggest you add some more chlorine. Also, do you have enough to do a proper SLAM? You will need to get to at least 10ppm. Need to advise us what % Liquid Chlorine you are using. I assumed 10% in my earlier calculation but best to have what you are actually using. Also, do you have any Borax (just the plain stuff you can purchase at grocery store). You may need some to raise pH but the better way is to aerate to raise pH. Do you have any type of water feature or spillover that can cause aeration? That will raise your pH. Right now it is ok to have a lower pH to SLAM. In fact, please read the SLAM Process

I as asking @mknauss or @Texas Splash to chime in on other thoughts.
Also suggest you Create Your Signature to help us understand all of your equipment, do you have a spa, any water features, etc.
All we know now is 30,000gals vinyl, possibly a DE filter. Please update with correct info.
I’m attaching a picture of the chlorine I’m using. Can you check to make sure it’s what I should be using? It says 12.5%.

I’m also attaching a few pictures of my pool. I don’t have any waterfalls or spill overs. I do have Borax on hand though. The pool has a shallow and deep end. In the deep end there is a 3 person spa seat. I do have a heater but haven’t turned it on yet.

I’m going to work on my signature to provide all info.
 

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That result was yesterday. I started fresh this morning with new tests but did not test TA. I will go get a sample and see if I get the same result though. Unless you don’t think it would really change much by a day? I’m not educated enough at this point to know. Only thing I’ve noticed so far is that changes drastically is FC. I’ve gone from FC being 5.8. yesterday afternoon to 0 this morning.
 
Only way TA changes is by adding something to raise the TA. That is baking soda, soda ash/washing soda, or high TA fill water.
 
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@Debbie17 As noted by Marty, it is really important to understand if you have any Akalinity in your pool.
I have attached another video for you to view. It is a 25ml water sample and you should see GREEN solution prior to adding the final drops to count.
 
Only way TA changes is by adding something to raise the TA. That is baking soda, soda ash/washing soda, or high TA fill water.
Ok! Thanks for that info. Pool math says if I add 5lbs it will raise TA by 19 and my TA needs to be 80-120. So I’ll go buy and add 5 lbs to start. How long after can I retest so I can add more if needed? Should I do this before I start the SLAM? And in the meantime should I add some chlorine since my FC is 0? I’m also still unsure if I need to adjust my PH and CYA before slamming.
 
@Debbie17 As noted by Marty, it is really important to understand if you have any Akalinity in your pool.
I have attached another video for you to view. It is a 25ml water sample and you should see GREEN solution prior to adding the final drops to count.
Thank you! I’m going to follow the video and retest before I do anything. Thanks to everyone for your patience with me. I’m so clueless. Trying to learn it all but feeling extremely overwhelmed. I appreciate so much you sharing your expertise with me.
 
Ok! Thanks for that info. Pool math says if I add 5lbs it will raise TA by 19 and my TA needs to be 80-120. So I’ll go buy and add 5 lbs to start. How long after can I retest so I can add more if needed? Should I do this before I start the SLAM? And in the meantime should I add some chlorine since my FC is 0? I’m also still unsure if I need to adjust my PH and CYA before slamming.
You just need to get your TA to above 50 ppm. And pH in the 7's. You will most likely need more than 5 lbs of soda ash. I would suggest getting 7lbs of baking soda too. Once you get some reading of TA, you will switch to baking soda to raise TA.

You need to do this now. Your water is destroying your liner and heater. Quickly.

Dissolve the soda ash in a bucket of water (may need to do a few batches). Pour in around the pool with pump running. Wait 30 minutes and test TA. If still 0, add another 5 lbs of soda ash. Once you see a TA reading, test pH and use baking soda to raise TA to between 50-80 ppm.
 
@Debbie17 I was reading another post on SLAM and these are the recommendations offered by @Newdude to a similar issue as you have. Hope this helps you understand the process.

Test and add chlorine, at first, every 2 hours is best as it will chew through your FC. After a day or 2, It will hold for 4 hours, then 6..... 8.... 12. The better you Maintain the FC up high, the quicker it goes. (That is why you have to have sufficient LC on hand) Once it’s gets blue and cloudy it’s mostly dead and you still maintain, but the battle shifts from a chemistry fight to a filter it all out fight. You still keep the FC up to not lose any ground, but the babysitting shifts focus to the filter. Backwash/rinse anytime the filter rises 25% of its psi.
I can absolutely relate to the fight with the filter. I’ve had to take mine apart to clean it 3 times already (Mon, Tues and today) after each vaccum. Every time I brush walls and vacuum the algae the filter pressure rises up because there’s so much of it that backwashing doesn’t even help. My filter has been completely black each time. So gross. I’m finally starting to see the light at the end of the tunnel though. One more vaccum tomorrow should get rid of any remaining dead algae.

I added some chlorine and focused on PH/ TA today and plan to work on CYA tomorrow so I can do a real SLAM finally. Thanks for all your help!
 

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