Oops, added muriatic acid instead of CH during slam

[calstar]

Second day of slam, cya is 50, need to keep FC at 20. This evening pool tested FC16, needed to add 2qts 1cp of chlorine, by mistake I added 2qts of muriatic acid, started slam with ph of 7.3, can't test for ph because of the high FC. Typically ph around 7.3 which I do to balance the high calcium level of water. So....should I keep the slam going, will the low ph screw up the slam, should I add some borax not knowing what the ph is to try and raise the ph(according to poolmath it will need a boatload)? thanks in advance

 

[Bperry]

Second day of slam, cya is 50, need to keep CH at 20. This evening pool tested CH16, needed to add 2qts 1cp of CH, by mistake I added 2qts of muriatic acid, started slam with ph of 7.3, can't test for ph because of the high CH level so I don't know how much it dropped, maybe as low as 6.4. TA is is high at 140 typically I need to add acid a couple of times a week to keep it around 7.3 which I do to balance the high calcium level of water. So....should I keep the slam going, will the low ph screw up the slam, should I add some borax not knowing what the ph is to try and raise the ph(according to poolmath it will need a boatload)? thanks in advance

Just measure the pH and adjust it. Im assuming you mean FC and not CH. we use FC for free chlorine and use CH for “calcium hardness”.

 

[mknauss]

What is the TA after the acid addition?

 

[proavia]

FC - free chlorine
CH - calcium

Please clarify your terms above.

If your FC is 16, retest in the morning and if FC is 10 or less. Then adjust pH to 7.2-ish and restart the SLAM.

If your present TA is above 50, you should be ok - according to Marty (@mknauss)

 

[calstar]

Yes brain fart, FC is what I meant and CH for calcium hardness. I corrected in OP, I will test TA in the morning. I thought measurements of ph at high FC level will be very inaccurate, why read the level to adjust the ph if I don't know what it is? I forgot to say I did add the 2qts of chlorine after I made the mistake but the reading was questionable after an hour of high pump speed(dual speed Pentair), the 2qts added should have raised the FC to targeted 20 but only tested at 18, previous readings following pool math quantities were spot on, new Taylor chemicals used.

 

[AUSpool]

With a TA of 140 a cup of acid won’t hurt. Just keep going with the SLAM. The lower then expected FC is well, to be expected during a slam. It’s being consumed while killing the algae.

 

[proavia]

With a TA of 140 a cup of acid won’t hurt. Just keep going with the SLAM. The lower then expected FC is well, to be expected during a slam. It’s being consumed while killing the algae.

OP added 2 quarts and 1 cup - 9 cups (72 oz) total.

 

[AUSpool]

Sorry, I read that as 2 quarts = a cup. However I’ll still go with everything thing is OK. I read a paper on algae blooms a while back that suggested that algae will adjust the pH by around two points either way. With the slam starting the day before at 7.3 and the TA at 140 I think we can safely assume the pH would be close to 7.5 at the acid addition which with a high TA would bring it down to around 7.0ish and it will start to rebound from there. Even it it went slightly sub 7 it wouldn’t be there for long. So no harm done. I wouldn’t go adding borax without knowing where it’s at.

 

[calstar]

TA this morning was 150, up from 140, that's adding 009 one drop at a time until the color red stops increasing in intensity., and that may have been do to variation in how the color change appears to me between the two readings(before and during slam testing) I've tried lowering the TA several tiimes in the last few years by aeration using pvc to bring both returns up above pool level creating "fountains", several days did not lower TA. FC was 16, down from 18 last night which is to expected on the OCLT as chlorine is eating algae. Ph reading this morning was 7.2, I don't understand how this can be accurate since I started slam with ph at 7.3 and mistakenly added 2qts of acid, only .1 lower after adding 2qts?? Instructions on slamming here on TFP expressly state ph readings are inaccurate when elevated FC is present and not to try testing it during slam, so where do I go moving forward. As mentioned above testing chemicals used are from a brand new TF-100 refill kit. I'm thinking letting the FC go down and to 7.5 or so, then test the ph and try to adjust accordingly. FYI the water is and was crystal clear. Suggestions/thoughts much appreciated

 

[PoolStored]

With a TA of 150, your pH will rise on its own. Continue the SLAM and don't worry about pH for now.

 

[proavia]

Let the FC fall to 10 or less
Retest pH and adjust accordingly
Restart the SLAM Process

Aeration does not affect TA - aeration will increase pH
Adding acid will lower pH and also lower TA a little.
So aerate to raise pH, add acid to lower pH to 7.2 - rinse, repeat. Your TA will slowly decrease.

While doing the SLAM, don't worry about testing anything but FC.

 

[calstar]

Sorry, I read that as 2 quarts = a cup. However I’ll still go with everything thing is OK. I read a paper on algae blooms a while back that suggested that algae will adjust the pH by around two points either way. With the slam starting the day before at 7.3 and the TA at 140 I think we can safely assume the pH would be close to 7.5 at the acid addition which with a high TA would bring it down to around 7.0ish and it will start to rebound from there. Even it it went slightly sub 7 it wouldn’t be there for long. So no harm done. I wouldn’t go adding borax without knowing where it’s at.

Thanks, I missed this post this morning before I posted the above TA, FC, and ph test results I got this morning. Your information seems to indicate I keep going with the slam which is good news, and no I won't add borax. I don't know how to estimate(as you do) the results of ph given the TA and the 2qts of acid I added, maybe the 7.2 ph reading I got this morning is close to correct after all despite what poolmath says

EDIT: Poolstore and Proavia, sorry, againI didn't see your posts before I entered this one. many thanks. Going forward I will let the ph drift down below 10(I'll continue brushing)and start slam over, probably could just continue with slam but as I just started it I won't mind the extra day or so of brushing/vacuuming, just gives me a little more peace of mind and a learning opportunity . thanks

 

[PoolStored]

The pH test is invalid when FC >10.

 

[calstar]

"It is actually the acid which lowers TA. Adding acid lowers both the PH and the TA. Then aeration raises the PH without changing TA. Do not use chemicals to raise your pH during this procedure (unless your pH accidentally goes way too low); that will just raise your TA back up, which is exactly what you are trying to avoid."

Yes I was wrong about aeration lowering the TA, now I know how it works. Above quote from pool school, I was thinking the aeration lowered the TA, now I see the acid does it. QUESTION regarding reading chemical levels: When testing for example TA do I take the reading when the color just changes to red(or pinkish red) or do I continue to add drops of 009 until they no longer change the color intensity at all? In this case the TA can read with a variation of 20ppm, depending when I took the reading. I would think with the 2 quarts of acid I added that the TA would have dropped quite a bit, maybe I was reading the test wrong. TFP and its members are great! Many thanks to all of you.

 

[cwswifty]

"It is actually the acid which lowers TA. Adding acid lowers both the PH and the TA. Then aeration raises the PH without changing TA. Do not use chemicals to raise your pH during this procedure (unless your pH accidentally goes way too low); that will just raise your TA back up, which is exactly what you are trying to avoid."

Yes I was wrong about aeration lowering the TA, now I know how it works. Above quote from pool school, I was thinking the aeration that lowered the TA, now I see the acid does it. QUESTION regarding reading chemical levels: When testing for example TA do I take the reading when the color just changes to red(or pinkish red) or do I continue to add drops of 009 until they no longer change the color intensity at all? In this case the TA can read with a variation of 20ppm. I would think with the 2 quarts of acid I added that the TA would have dropped quite a bit, maybe I was reading the test wrong. thanks

Total Alkalinity Test

TA has a buffering effect on pH, preventing it from moving suddenly. Good TA readings will be around 70-90 for saltwater pools and 100-120 for normal pools.
1. Rinse and fill the clear plastic cylinder to the 25ml mark
2. Add two drops of R-0007 and mix. Then, add 5 drops of R-0008 and mix again. Solution will turn green.
3. Add R-0009 one drop at a time, swirling between each drop. Wipe the tip of the bottle after every drop with a damp cloth. Continue ‘til color changes to red. Multiply the number of drops you added times 10. (11 drops = T/A 110) Record it. TA can vary widely. but a range of 70-120 normally works well.

Once you add a drop and see no further color change, don't count that drop and you're done.

 

[calstar]

Mustard algae SLAM is not a thing... Mustard Algae levels are a separate part of the SLAM Process

TA would bring it down to around 7.0ish and it will start to rebound from there. Even it it went slightly sub 7 it wouldn’t be there for long. So no harm done. I wouldn’t go adding borax without knowing where it’s at.

With a TA of 150, your pH will rise on its own. Continue the SLAM and don't worry about pH for now.

Let the FC fall to 10 or less
Retest pH and adjust accordingly
Restart the SLAM Process

Aeration does not affect TA - aeration will increase pH
Adding acid will lower pH and also lower TA a little.
So aerate to raise pH, add acid to lower pH to 7.2 - rinse, repeat. Your TA will slowly decrease.

While doing the SLAM, don't worry about testing anything but FC.

Total Alkalinity Test

TA has a buffering effect on pH, preventing it from moving suddenly. Good TA readings will be around 70-90 for saltwater pools and 100-120 for normal pools.
1. Rinse and fill the clear plastic cylinder to the 25ml mark
2. Add two drops of R-0007 and mix. Then, add 5 drops of R-0008 and mix again. Solution will turn green.
3. Add R-0009 one drop at a time, swirling between each drop. Wipe the tip of the bottle after every drop with a damp cloth. Continue ‘til color changes to red. Multiply the number of drops you added times 10. (11 drops = T/A 110) Record it. TA can vary widely. but a range of 70-120 normally works well.

Once you add a drop and see no further color change, don't count that drop and you're done.

"Once you add a drop and see no further color change, don't count that drop and you're done."

Thanks for answer that

 

[AUSpool]

Thanks, I missed this post this morning before I posted the above TA, FC, and ph test results I got this morning. Your information seems to indicate I keep going with the slam which is good news, and no I won't add borax. I don't know how to estimate(as you do) the results of ph given the TA and the 2qts of acid I added, maybe the 7.2 ph reading I got this morning is close to correct after all despite what poolmath says

EDIT: Poolstore and Proavia, sorry, againI didn't see your posts before I entered this one. many thanks. Going forward I will let the ph drift down below 10(I'll continue brushing)and start slam over, probably could just continue with slam but as I just started it I won't mind the extra day or so of brushing/vacuuming, just gives me a little more peace of mind and a learning opportunity . thanks

Just continue the SLAM.

Don’t worry about the acid addition, your back on track on the SLAM.

pH moves, mostly up. Acid drops it down. We don’t normally bother with pH testing during a SLAM. Free chlorine, FC, above 10ppm can bleach out the pH die but it normally makes the pH look high. But a pH result of 7.2 is roughly where I would expect you to be. You started the SLAM at 7.3, adding bleach and the high total alkalinity will cause it to rise. It was probably at 7.5 when you added the acid which brought it down. More bleach, the high TA and time would have brought it back up. Just continue the SLAM, your all good.