UPDATE DAY 3: SEE PICS from Green Pool, Cloudy to DAY 3 - CYA 60, FC 5, TC 5, Ph 7.6, TA 100 NOW WHAT???

[MAGnet_ManNY]

Rookie mistake here, CYA Testing kit liquid replacement for my Taylor 2006 is shipping but I decided to use test strips in the interim but misread CYA adding stabilizer where none was probably needed. Thus, high CYA reading of 80 and clear water no longer clear and turning green (see picture). FC is 4 but obviously not working and my Ph 7.8 & TA 110 are a little high. In reading here it looks like I need to add muratic acid to lower Ph (maybe as low as 7.2) and/or do SLAM and/or add Liquid Chlorine to get FC to level of 9-11 and/or lower pool water and and add more water.

My question is which of these do I do and in what order?

I am leaning to adding the Muratic Acid to lower Ph to 7.2 and then do SLAM (but do I wait a day or an hour or other time after adding Muratic Acid)? I could also lower water before or after SLAM.

The other choice I was thinking of was adding Liquid Chlorine (after Muratic Acid as in the last example) to get level to 9-11 and then possibly lowering/adding water.

Please see picture and advise. My thinking is that with sunny, warm South Florida Weather with near 0% rain chance that I need to act sooner rather than later.

 

[amwillg]

Note: I also claim novice status, so hopefully the experts chime in soon.
As you've noticed, the 4ppm FC won't cut it with your CYA level. Getting it up to target range will help, but is for maintenance. Looks like SLAM is coming up, but its not easy to do a SLAM at CYA of 80. I expect smarter minds will recommend some water replacement to get CYA down, then muriatic acid to get pH 7.2, then SLAM levels of Cl.

 

[MAGnet_ManNY]

Note: I also claim novice status, so hopefully the experts chime in soon.
As you've noticed, the 4ppm FC won't cut it with your CYA level. Getting it up to target range will help, but is for maintenance. Looks like SLAM is coming up, but its not easy to do a SLAM at CYA of 80. I expect smarter minds will recommend some water replacement to get CYA down, then muriatic acid to get pH 7.2, then SLAM levels of Cl.

Thanks for the feedback. I put in Muratic Acid after the post and Ph dropped... The new readings as of 6 PM are TC 4, FC, 4, CC 0, PH 7.4, TA 100, CYA 80

 

[YippeeSkippy]

You have two choices. One is you keep 80 whatever parts per million of CYA in the pool and after a SLAM process, you keep using a LOT more chlorine than normal to keep the pool clear.
Second choice is to drain the water by half and replace with fresh, CYA free water.

Then you perform a SLAM process to rid your pool of the algae that took hold when your CYA was too high for the amount of FC you were giving the pool.
SLAM Process

FC/CYA Levels

Any questions

Maddie

 

[YippeeSkippy]

As you are in Miami, I would be very cautious draining the pool. We don't want it to float! Try this instead-

Draining - Further Reading

www.troublefreepool.com

 

[DeanP66]

You only need about a 37.5% drain and refill. That will get your CYA down to 50, which is probably where you want it in Miami. Although your SLAM level will be a little higher (20ppm), that will only be the initial dose. Then you just top it back up to 20 during your SLAM and when you're done, you're at the perfect CYA level for you and you've drained less water.

 

[MAGnet_ManNY]

You only need about a 37.5% drain and refill. That will get your CYA down to 50, which is probably where you want it in Miami. Although your SLAM level will be a little higher (20ppm), that will only be the initial dose. Then you just top it back up to 20 during your SLAM and when you're done, you're at the perfect CYA level for you and you've drained less water.

Thanks for the info. That is certainly a relief. 37.5% is better than 50%, 75% or more. Problem is that here in Miami, pool filling credit is only given once per calendar year and I've already used that in 2021 so I may need to ride it out until January unless I can do it in several stages to soften the blow$ but not sure that is possible.

 

[IceShadow]

You can SLAM at CYA 80, but your target will be 31ppm of FC. So I guess the question is: do you have a steady supply of cheap liquid chlorine, or will it cost less to replace water first?

 

[MAGnet_ManNY]

UPDATE: DAY 3 after slamming day 1 with CYA 80 per TFP (about 540 fl Liquid Chlorine), Day 2 SLAM (again 540 fl oz Liquid Chlorine 10%) AND it RAINED HEAVILY (Like typical South Florida Summer shower) in the early evening. Before the shower I had removed 3+ inches of pool water (via Vacuum and Backwash) and had rain and water from garden hose refill. See results in picture (big difference from before SLAM): No longer green but not yet 100% clear. CYA now measured at 60, TA still 100 FC way down now to 5 though with sun and rain, 7.6 PH. I Vacuumed and did another Backwash an hour ago dropping pool water 4+ inches. It has been raining for the last hour and will top that off with garden hose when done.

I have read that SLAM should be continued until water is clear and color is good. Does that mean I should slam to DAY 1/DAY 2 levels (540 fl oz of Liquid Chlorine) or should I put in the new readings that I measured this evening before tonight's rain storm OR should I do new readings after the rain and SLAM off those readings. Please Advise. Thanks to everyone for your help!

 

[IceShadow]

The amount of chlorine you add will depend on your SLAM target for your CYA, your current FC level, and how big your pool is. It’s not a set amount each day - it’s a varying amount depending on how much you need to get your FC up to the target. Test FC every couple of hours if you can and add after each test to reach the target.

Now that the green is mostly gone it’s a filtering game to remove the dead algae, but you don’t want to allow it to come back while you’re filtering the dead stuff out. So keep the FC up at SLAM level as much as you can.

 

[DeanP66]

You can adjust down to CYA 60 now that it has dropped. So, your target FC will now be 24 ppm.

 

[MAGnet_ManNY]

The amount of chlorine you add will depend on your SLAM target for your CYA, your current FC level, and how big your pool is. It’s not a set amount each day - it’s a varying amount depending on how much you need to get your FC up to the target. Test FC every couple of hours if you can and add after each test to reach the target.

Now that the green is mostly gone it’s a filtering game to remove the dead algae, but you don’t want to allow it to come back while you’re filtering the dead stuff out. So keep the FC up at SLAM level as much as you can.

Ok, I will check levels again shortly this morning, I added some more water had a question regarding PH since I had read that it can vary some during SLAM. Do I adjust this down from 7.6 to maybe 7.4 or 7.2 to lower TA to target of 80 for my pool or do I not concern myself with that until my SLAM process is done? Let me preface this with the fact that my pool was resurfaced at the end of March (so I am already past the brush twice a day, brush once a day & other newly plastered advice).

I am receiving my FAS/DPD replacement chems today. Should I just wait until they arrive sometime later this afternoon or measure as I have been for Chlorine with my Taylor kit sans FAS/DPD?

Thanks!

 

[IceShadow]

Without the FAS/DPD testing you’re kinda flying blind so wait for that.

pH testing is not reliable if FC is over 10, and you can’t tell if that’s the case right now. Wait for the reagents, test again. If below 10 FC and you can trust the pH reading, go ahead and take it back down to 7.2 and then continue the SLAM.

I don’t have experience with plaster pools but perhaps some of the cloudiness is from the fresh plaster?

 

[MAGnet_ManNY]

After resurfacing my pool, I replaced the sand in my sand filter because it had degraded badly over the last 7 years+. Now, reading here on TFP, I have not found the answer to this question. For a sand filter with new sand, do you add DE (And if so then how much?). I believe the recommendation is to backwash the sand filter adding new sand, so my first guess is to add it after that initial backwashing and EVERY time you backwash the sand filter, correct??

Lastly, how OFTEN do you need to BACKWASH? Is it per what I followed before when pressure went up considerably or is there another TFP Rule of Thumb for backwashing??

 

[MAGnet_ManNY]

IceShadow, saw that you have a Sand Filter. I also have one and just asked in newbie section regarding adding DE to a sand filter with newly replaced sand and also if there were any TFP Rule of Thumb's for backwashing (I had always followed it was necessary after pressure went up a one full PSI) and just wondering your experience/thoughts on these?

 

[amwillg]

Backwashing is generally done when pressure goes 25% higher than baseline.
DE is optional and not required for sand filters; only required for DE filters. If you do want to use some DE for extra clarification/finer filtration, it is added after backwashing since it will get backwashed out each time. With the TFP method, the filtration provided by the sand itself will be just fine.

 

[mknauss]

After resurfacing my pool, I replaced the sand in my sand filter because it had degraded badly over the last 7 years+. Now, reading here on TFP, I have not found the answer to this question. For a sand filter with new sand, do you add DE (And if so then how much?). I believe the recommendation is to backwash the sand filter adding new sand, so my first guess is to add it after that initial backwashing and EVERY time you backwash the sand filter, correct??

Lastly, how OFTEN do you need to BACKWASH? Is it per what I followed before when pressure went up considerably or is there another TFP Rule of Thumb for backwashing??

Add DE to a Sand Filter

A clean pool filter will increase the efficiency of your pool! ... your filter are to backwash it, clean the manifolds and grids, and add new DE.

www.troublefreepool.com

 

[MAGnet_ManNY]

You can adjust down to CYA 60 now that it has dropped. So, your target FC will now be 24 ppm.

Thanks, Dean.... anxiously awaiting my FAS/DPD reagents resupply this afternoon to test

Backwashing is generally done when pressure goes 25% higher than baseline.
DE is optional and not required for sand filters; only required for DE filters. If you do want to use some DE for extra clarification/finer filtration, it is added after backwashing since it will get backwashed out each time. With the TFP method, the filtration provided by the sand itself wil

Add DE to a Sand Filter

A clean pool filter will increase the efficiency of your pool! ... your filter are to backwash it, clean the manifolds and grids, and add new DE.

www.troublefreepool.com

As you are in Miami, I would be very cautious draining the pool. We don't want it to float! Try this instead-

Draining - Further Reading

www.troublefreepool.com

Great article and since I am here in South Florida, I have decided to move more slowly with this and use the downpours that begin as the late Spring/early Summer kick in to my advantage by lowering the pool before the afternoon showers roll in and use rain water along with garden hose to replace water. Had a big shower the last two afternoons/evenings and lowered pool beforehand each time before refilling (rain+garden hose) and my confirmed CYA dropped from 80 to 60. So, I am encouraged this will save me some $ from taking the initial hit of emptying down to to needed levels & then refilling all at once.