SLAM question

rcs101

Member
Oct 24, 2013
11
Friendswood, TX
I'm working on my third day and have seen improvement in the water clarity, but FC is still inconsistent.

My CYA is 40, ph is 7.5, TA 130.

I'm adding smaller amounts of chlorine, 40 to 60 ounces, trying to get a shock level of 16. An hour after I add I'm still 1.5 points low of my goal. Swings were more exaggerated yesterday. What exactly does a "substantial fraction" represent, phrase taken from Turning Your Green Swamp article. Filter is working fine, backwashing every 8 hours. I've brushed the entire pool each day while chlorine level in the pool is at least at the shock level. When can I come off the Shock level?
 

Tvarnell

Well-known member
Jun 21, 2016
83
Central Oklahoma
Come off shock level when it 8s clear. That being said I really haven't done that to well lately. But it has been over a Month and half for me.

Sent from my SAMSUNG-SM-G920A using Tapatalk
 

Mr Bruce

TFP Guide
Mar 24, 2014
2,095
Greenville, SC
3 days is nothing. If you continue to see any improvement, keep doing what you are doing. Thoughts:

- Don't bother to test for anything other than FC / CC until you are done with your SLAM.
- Don't backwash the filter until the pressure gauge is 25% higher than what it is right after you backwash it.
- Don't look for consistency in FC loss.
- Don't go too crazy :) Test and add a few times a day, not as frequent as every hour (especially after Day 1). And brush once a day, like you said you were.

The SLAM article has the criteria for ending. Pool School - SLAM - Shock Level And Maintain

Take a picture everyday if you need convincing that it's getting clearer. :)

Edit for clarity. The FC should be tested and added more than twice a day but less than once an hour. Sounded like you driving yourself crazy, what frequency are you testing at?
 

rcs101

Member
Oct 24, 2013
11
Friendswood, TX
3 days is nothing. If you continue to see any improvement, keep doing what you are doing. Thoughts:

- Don't bother to test for anything other than FC / CC until you are done with your SLAM.
- Don't backwash the filter until the pressure gauge is 25% higher than what it is right after you backwash it.
- Don't look for consistency in FC loss.
- Don't go too crazy :) Test and add a few times a day, not as frequent as every hour (especially after Day 1). And brush once a day, like you said you were.

The SLAM article has the criteria for ending. Pool School - SLAM - Shock Level And Maintain

Take a picture everyday if you need convincing that it's getting clearer. :)

Edit for clarity. The FC should be tested and added more than twice a day but less than once an hour. Sounded like you driving yourself crazy, what frequency are you testing at?
I wasn't as anal the first couple days as I have been today. Been testing FC every hour, but my concern has been that I'm not getting to the shock level after an hour.
It's actually kinda fun, but I can become as fascinated by the process and trying to interpret that information and lose sight of the evidence that the pool water is improving and that it's working. :confused:results
 

Mr Bruce

TFP Guide
Mar 24, 2014
2,095
Greenville, SC
If you are never able to actually get to the SLAM level say after 20-30 minutes after adding with the pump running, it's possible

a) The chlorine is weaker than you think
b) Your pool is bigger than you think or
c) (unlikely IMO) You have a testing error.

If it were me I would be tempted to aim 1-2 ppm higher for a FC goal just to see what would happen. If in 20 minutes I got a 16 I would raise my pool volume by 2k and work from there.

Once an hour is too much, unless you just feel like it and don't mind burning through testing chemicals. Once every 2 hours is plenty, most people don't have that kind of time :)
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
20,404
San Dimas, CA (LA County)
If you are never able to actually get to the SLAM level say after 20-30 minutes after adding with the pump running, it's possible

a) The chlorine is weaker than you think
b) Your pool is bigger than you think or
c) (unlikely IMO) You have a testing error.

If it were me I would be tempted to aim 1-2 ppm higher for a FC goal just to see what would happen. If in 20 minutes I got a 16 I would raise my pool volume by 2k and work from there.

Once an hour is too much, unless you just feel like it and don't mind burning through testing chemicals. Once every 2 hours is plenty, most people don't have that kind of time :)
My thoughts exactly. Saves me typing. :goodjob:
 

rcs101

Member
Oct 24, 2013
11
Friendswood, TX
Several days later and the chlorine demand during the day isn't decreasing, water is much clearer, but still cloudy. I"ll bring it up to shock level at night and it stays within a 1-2 full points between last test at dark and first test before daylight.
By 12 pm the following day and not adding chlorine since the slab level was ok, the FC level several hours later has dropped 5-6 full points, after bring back to shock level and testing again that evening the FC level has dropped as much as 10 full points. Is this normal? I'm adding 3-5 gallons a day.
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
20,404
San Dimas, CA (LA County)
Several days later and the chlorine demand during the day isn't decreasing, water is much clearer, but still cloudy. I"ll bring it up to shock level at night and it stays within a 1-2 full points between last test at dark and first test before daylight.
By 12 pm the following day and not adding chlorine since the slab level was ok, the FC level several hours later has dropped 5-6 full points, after bring back to shock level and testing again that evening the FC level has dropped as much as 10 full points. Is this normal? I'm adding 3-5 gallons a day.
No. Demand should have fallen off by now.

A few things: can you see the floor, and is there any organic debris still in there?

Have you carefully checked ladders, steps, and lights?

Check out the pictures
Think I may have found my FC demand issue?
Water problems
Problem Found and Ideas needed
 

rcs101

Member
Oct 24, 2013
11
Friendswood, TX
I can see the drain covers in the deep end, though not clearly. There's a small amount of silty beige or gray along one of the seam lines that clouds up when I brush.

The ladder is frozen in the expansion anchors and I can't disassemble, but the outside has been thoroughly cleaned. I'll have to see if I can figure out how to get it apart without destroying the pipe.

I'll pull the light apart and check.

Filter seems to be working fine, but it's 4 years old. I've been planning on pulling the filter apart and deep cleaning but haven't, should I?

I checked out your links, Thanks.
 

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