Filter and pump sizing issue?

skimmerswimmer

Well-known member
Jul 30, 2013
357
Long Island, NY
Going far above your target slam level will not kill the algae any faster and could potentially cause other issues with your liner and equipment. If your target is 20 and you go a few ppm over, that is fine. I wouldn’t recommend swimming if you’re over slam level though.
 

TazJMT

Well-known member
Jun 19, 2014
97
Spotswood, NJ
Going far above your target slam level will not kill the algae any faster and could potentially cause other issues with your liner and equipment. If your target is 20 and you go a few ppm over, that is fine. I wouldn’t recommend swimming if you’re over slam level though.
No, I'm not doing that, I measured it to the exact ounce. I was just saying that even if i were to go way over, it is night time so i shouldnt lose anything if there was no issue. Meaning if my CYA is 40 i should SLAM at 16. I did 20 assuming CYA 50 just in case and should stay at 20 if all is good
 

setsailsoon

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Oct 25, 2015
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Stuart/FL
Surprising result. SLAMed the pool to 20 FC (from 3, added 17 with 1 gal, 1 qt, 2 cups). Checked an hour and a half later, was down to 16.5. Doing this after dark (how do people SLAM in the daylight and account for the light eating the FC?). Just added 3.5 more, going to check in an hour or so before bed.

Stunned it lost anything. Every day it was losing about 3 and water was clear, that did not stir up any suspicions on my part

As i said, i am SLAMing for a 50 CYA even though i am pretty sure i am lower than that-but i assume i can go as high as i want with FC at night-even if i put 100 FC in it (i won't) it shouldnt lose any at night, right?
Just test a little more frequently and adjust FC to SLAM level (or a little higher). SLAM is a 24/7 process that usually takes several days or more. During first stage FC consumption can be very high and require a LOT of liquid chlorine depending on how bad the bloom is. After that FC loss drops a lot and most of the work is done by your filter.
 

duraleigh

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Apr 1, 2007
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Taz,

1. Don't sweat the difficulty in reading CYA test. Pour it back and forth into the view tube as if you were taking a brand new sample each time and then take the average of your three observations.....you'll be close enough.

2. You're confusing your SLAM process and the OCLT. Replenish your SLAM value of FC 24/7......the daylight loss is really irrelevant to the goal of the SLAM. Now, when you perform the OCLT, you are eliminating daytime UV loss so your remaining loss is organic only.

3. As posted above, don't add FC wa-a-a-ay over the suggested dosage for SLAM. It can damage your liner and does little good anyway.
 

anotherpyr

Well-known member
Jun 22, 2007
90
Columbia, MD

TazJMT

Well-known member
Jun 19, 2014
97
Spotswood, NJ
Taz,

1. Don't sweat the difficulty in reading CYA test. Pour it back and forth into the view tube as if you were taking a brand new sample each time and then take the average of your three observations.....you'll be close enough.

2. You're confusing your SLAM process and the OCLT. Replenish your SLAM value of FC 24/7......the daylight loss is really irrelevant to the goal of the SLAM. Now, when you perform the OCLT, you are eliminating daytime UV loss so your remaining loss is organic only.

3. As posted above, don't add FC wa-a-a-ay over the suggested dosage for SLAM. It can damage your liner and does little good anyway.
2) I am not confusing the 2, i am just saying that it is easier to do when there is no light because then there is no sunlight loss at all. I know the sunlight loss is not significant, but losing 0 when it is dark is better than accounting for an insignificant amount, in my opinion. I understand SLAM is done all day (and wonder how people with a day job do it-i am off this week)

I also assumed this SLAM would not take as long as some because if there is something organic in the water, it can't be much since the water looks so good.

3) I was merely making an analogy that seems to have not landed. Again, I am not saying I would bring my FC up to 100! All I was saying is that I might have overdone the FC by doing 20 (for a 50 CYA) instead of 16 (for a 40 CYA), but no matter how high I brought it, even to 100 (which I would NEVER DO), I shouldn't be losing anything when SLAMing in nighttime hours unless there is something organic in the water
 
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TazJMT

Well-known member
Jun 19, 2014
97
Spotswood, NJ
Ok, on to some results-added to get to 20 before bed, woke up and checked it at 9am-it is a very cloudy day, so i would assume there isn't much effect from the light. I got a result of 17.5

But, we did get unexpected rain last night-not sure how much but at least 1/2 inch. That would have diluted a bit and given me a little more of a false FC loss. Yes I know it wuoldnt have been too much and yes I know I am not done, just bringing it up since it happened
 

TazJMT

Well-known member
Jun 19, 2014
97
Spotswood, NJ
Taz,

1. Don't sweat the difficulty in reading CYA test. Pour it back and forth into the view tube as if you were taking a brand new sample each time and then take the average of your three observations.....you'll be close enough.
I forgot to ask-ask far as CYA goes, here is my trouble. I think I can still see it when I know I am way past (lower/more weater in tube) than I should. Even this picture frm the link below from pool school/taylor shows when the test is ended and i think you can still see a black dot in there faintly

 

setsailsoon

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Oct 25, 2015
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Taz,

You're having the same problem I had. Don't over-work the problem and don't over-focus on the word "disappear". If the dot looks like the bottom view, you're done. I find it helps to look up then back down each time I add drops. If you really want to check yourself there is a standard solution of 50ppm cya that's available. You test it and fill the tube to 50 ppm. This shows what the dot should look like. But it's not really needed. The more you do the test the better you'll get.

I hope this helps.

Chris
 

TazJMT

Well-known member
Jun 19, 2014
97
Spotswood, NJ
Taz,

You're having the same problem I had. Don't over-work the problem and don't over-focus on the word "disappear". If the dot looks like the bottom view, you're done. I find it helps to look up then back down each time I add drops. If you really want to check yourself there is a standard solution of 50ppm cya that's available. You test it and fill the tube to 50 ppm. This shows what the dot should look like. But it's not really needed. The more you do the test the better you'll get.

I hope this helps.

Chris
@setsailsoon
yes it does-thanks! I always say disappear or totally gone here, good to know I'm not alone

do you find doing it in daylight is any different? i have seen that advice also
 

setsailsoon

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Oct 25, 2015
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Stuart/FL
@setsailsoon
yes it does-thanks! I always say disappear or totally gone here, good to know I'm not alone

do you find doing it in daylight is any different? i have seen that advice also
Taz,

Yes, just like the instructions say I find sunlight behind me is best and most repeatable. It's very difficult to do without sunlight. Also, you can repeat the test by pouring the mix back into the bottle. You can do it over and over 'till you're confident in the result. You'll find that you can almost start imagining a faint outline of the dot. As soon as it gets this close you're done. Take the reading as the next highest level on the tube. This test uses a logarithmic scale so you always round up.

Good luck!

Chris
 

TazJMT

Well-known member
Jun 19, 2014
97
Spotswood, NJ
Taz,

Yes, just like the instructions say I find sunlight behind me is best and most repeatable. It's very difficult to do without sunlight. Also, you can repeat the test by pouring the mix back into the bottle. You can do it over and over 'till you're confident in the result. You'll find that you can almost start imagining a faint outline of the dot. As soon as it gets this close you're done. Take the reading as the next highest level on the tube. This test uses a logarithmic scale so you always round up.

Good luck!

Chris
Thanks-i am always confident i see it the exact same way, i was just never confident that it was totally gone until way past where i should be