Thinking I Need to SLAM and the Rain!

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Dave, that's a big drop overnight compared to where you were a couple days ago (so close). Now may be a good time to step-back and review some SLAM basics. Perhaps start by verifying your CYA again under good sunlight to ensure your FC is still correct. I recall when you first started you had some confusion about FC testing, so hopefully that's good by now, but if you aren't sure let us know. If it is, then something must still be generating new algae and/or more scrubbing is required to break-up the old stuff. Did we ever discuss a light? I don't recall. If you have a large light, pull it out (power off first) and check the light niche. It's a very common place. Inspect and steps or ladders that may be in the water. Leave no stone un-turned. :)
 
Texas Splash said:
Dave, that's a big drop overnight compared to where you were a couple days ago (so close). Now may be a good time to step-back and review some SLAM basics. Perhaps start by verifying your CYA again under good sunlight to ensure your FC is still correct. I recall when you first started you had some confusion about FC testing, so hopefully that's good by now, but if you aren't sure let us know. If it is, then something must still be generating new algae and/or more scrubbing is required to break-up the old stuff. Did we ever discuss a light? I don't recall. If you have a large light, pull it out (power off first) and check the light niche. It's a very common place. Inspect and steps or ladders that may be in the water. Leave no stone un-turned. :)
Click to expand...

OK retested my CYA in bright sunlight as suggested and it came out between 50 and 60. Previous test before starting the SLAM process was 60 so I am targeting FC of 24. I am confident in the FC test process so can only presume there is something in the water using the FC!

Nooks and crannies - don't have any steps. There is an umbrella stand (hole is the bottom of the sun shelf) and the only way I can clean that is by jetting water from a hose pipe, unless I get a bottle brush. It appears to be clean and if there were any algae in there I wouldn't have thought it would result in such a large drop in FC? I have two lights and was thinking of pulling them although not sure i can get the one in the deep end, at least not without some difficulty.

Wondering if maybe I need to clean my cartridge filter. When clean the pressure is at 10psi, it is currently at 12psi so wouldnt have thought that was a problem either.

Just checked my skimmers and there are quite a few dune bugs in there. I also mowed the yard yesterday and although I made a point of skimming out the bit of grass that was in there, maybe there was some residue from that.

I will persevere. Keep the FC target of 24, and OCLT again tonight

Thanks
Dave
 
Kept my target FC at 24 today. Was a bright sunny day and added a total of 4 x 121oz 8.25% bleach to keep FC at or near target.

Tonight I tested at 8.10pm, sun had not set although there was no sun on the pool. FC was at 21. Per PoolMath added another 83oz to get FC to target of 24. Just tested again an hour later and FC is at 22 - seems odd! Don't plan to add any more tonight - will see what the OCLT tells me. Wish me luck!
 
Think I am nearly there - first time I have had the exact same results overnight.
Results of OCLT:
FC Loss = 0.0
CC = 2.0
Water is crystal clear

Will keep at it today and OCLT again tonight and hopefully see the CC go down to 0.5 or less

Dave
 
Well, really thought I was going to get there but then the rain came again and I am guessing that threw everything off.......Had a fairly heavy rain storm and then quite steady rain for a few hours yesterday afternoon.

A new question I have - does it make sense for FC to reduce overnight but CC to stay constant? Tested at 8:30 last night, FC = 23.5 and CC = 2.0

Tested at 5:15 this morning and FC=20.0 and CC=2.0

It seems to me that if the FC is reducing overnight that would mean it is working to reduce contaminants. From what I have read that means the FC is reacting with whatever nitrogen or ammonia compounds are present in the water and that would create CC. Hence my thinking that if FC goes down overnight then CC should go up? Am I missing something here?

Also, how does the CC go down. I understand it can go down by being burnt off by sunlight, but what about overnight, can it still breakdown without sunlight? If CC cannot break down without sunlight then that would indicate that unless my CC is 0.5 or less just after sunset then I cannot pass an OCLT since the CC will not reduce further?

As always appreciate all the help here!

Thanks
Dave
 
Yes it makes since that FC can reduce overnight and CC stay the same. While FC can show up as CC after it has been used, it doesn't mean that all used FC shows up as CC. FC does break down CC and sunlight also breaks down CC. While your CCs have been pretty high, you should not think that since your CC number has remained the same, doesn't mean that none of your CCs has been broken down.

Have you pulled out your lights and cleaned behind them? You could have some nasty stuff behind there and it could be what is keeping you from finishing your SLAM.

Not sure when you last cleaned your cart filters, but you should be cleaning them when the pressure is 25% higher than you clean pressure. I believe you posted earlier that your clean pressure is 10, so you should be cleaning them when your pressure reaches 12.5.
 
kcindc said:
Yes it makes since that FC can reduce overnight and CC stay the same. While FC can show up as CC after it has been used, it doesn't mean that all used FC shows up as CC. FC does break down CC and sunlight also breaks down CC. While your CCs have been pretty high, you should not think that since your CC number has remained the same, doesn't mean that none of your CCs has been broken down.

Have you pulled out your lights and cleaned behind them? You could have some nasty stuff behind there and it could be what is keeping you from finishing your SLAM.

Not sure when you last cleaned your cart filters, but you should be cleaning them when the pressure is 25% higher than you clean pressure. I believe you posted earlier that your clean pressure is 10, so you should be cleaning them when your pressure reaches 12.5.
Click to expand...

Thanks for the response. Have not pulled the lights yet - you will see from previous posts that OCLT this last Saturday everything stayed constant but the CC still did not pass. Figured I was almost there so just stuck at it and did OCLT again last night, was thinking that the rain storm yesterday afternoon messed it up - I'm sure that will have washed some nasties into the pool. The lights were next on the list to check behind if all else failed.

Interesting what you say about the cartridge filter - I did not know that. The pool company who did their 'pool school' with me told me I don't need to clean the filters till the pressure is at 20psi (that is also marked on the pressure gauge). Pressure is curently right around 12psi so could be time to pull the filters and clean them. May be able to do that later tonight and then run an OCLT again tonight

Thanks
Dave
 

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It seems I am almost there (again!)

Last night test results at 9.30pm: FC 26, CC 2.5
This morning test results at 5:20am: FC 26, CC 3.0
Water is crystal clear

Just need CC to go down!

Immediate problem I have now is that this morning I have run out of R-0871 reagent. I have more on order and it is in the mail but I don't think it will arrive today.

I know that 25oz of 8.25% bleach raises my FC by 1.0 so I am thinking that if I don't receive the new reagent today I will just add 2 jugs (242oz) 8.25% bleach tonight to keep the FC reasonably high and then carry on when I have the reagent - does this seem like a good approach?

Thanks
Dave
 
I am still in the middle of my SLAM process and waiting for a new bottle of reagent to arrive in the mail. I am sure I am really close to finished, just need the reagent so I can retest. In the meantime keeping my FC high by adding a couple bottles bleach each day.

So with regard to the testing I just came across this thread with the Extended Test Kit Directions:

http://www.troublefreepool.com/threads/24188-Extended-Test-Kit-Directions

The interesting point for me is that it says here that the FAS-DPD test when testing at high FC levels is accurate within 10%. So if I am targeting FC 24, when I get a result that gives me that FC, the true FC could be anywhere between 21.6 and 26.4

Assuming the test is done correctly each time, if two tests both show FC 24, then it is not possible that the two tests could be on opposite ends of the accuracy range i.e. one test shows FC 24 but due to accuracy the true FC is 21.6 and then the next test shows FC 24 but the true FC is 26.4. Maybe I am getting too into the weeds here but interested to hear any input

I also wish I had read the thread sooner as I think it is possible I was using too little R-0870 powder early on in my SLAM process and that was why I was getting some wild results. Note that the instructions say 'add one heaped spoon or two level spoons of powder' and also within reason more is better. I think some of my tests the spoon was possibly not really heaped!

This site is great - learning so much about maintaining my pool

Thanks to y'all
Dave
 
Not sure which kit you started with, but the TF-100 comes with an instruction card and clearly states to use one heaping scoop of powder and not to worry if some of the powder doesn't dissolve.

Using the 25 ml fas-dpd test is more accurate than the 10 ml. Generally, the 10 ml is good enough for a SLAM and good enough for most applications. As long as you are consistent with your scoops and drops, I wouldn't sweat this.

Try your best to control what you can, the size of the scoop, keeping the water meniscus line of the sample tube consistent, keeping track of the # of drops you've added and having a speedstir helps.
 
kcindc said:
Not sure which kit you started with, but the TF-100 comes with an instruction card and clearly states to use one heaping scoop of powder and not to worry if some of the powder doesn't dissolve.

Using the 25 ml fas-dpd test is more accurate than the 10 ml. Generally, the 10 ml is good enough for a SLAM and good enough for most applications. As long as you are consistent with your scoops and drops, I wouldn't sweat this.

Try your best to control what you can, the size of the scoop, keeping the water meniscus line of the sample tube consistent, keeping track of the # of drops you've added and having a speedstir helps.
Click to expand...

Thanks - figured I might be getting too far into the weeds there! I have the TF-100 so know it is meant to be heaped, but when I read that thread and it said 'one heaped or two level scoops' it made me think maybe I wasn't heaping enough.

I have definitely learned that consistency is key, and of late have been a lot more careful to ensure I am consistent with the volume of water i.e. I always aim for bottom of meniscus on the 10ml mark. I think when I started the SLAM process I wasn't being careful enough about that!

Also thinking maybe I should get a speed stir

Thanks
Dave
 
After a longer than expected wait on the USPS finally got my replacement R-0871 and recommenced the SLAM yesterday. I had maintained the FC fairly high while waiting for the reagent to arrive just by adding 2 jugs of 8.25% bleach each evening.

Didn't expect to pass the OCLT straight off the bat but....
Last night at 10:30:
FC = 21.5
CC = 0.0
Water Clear

This morning at 6:20
FC = 21.0
CC = 0.5 (could actually have been 0 but I added a drop to make sure it really was clear!)
Water is Crystal.....

IMG_1107.jpg

Thanks again to all for your help - this forum is AWESOME :D

Dave
 
Thanks for the congrats - pool is looking awesome and we are actually getting some good weather so been swimming all weekend :D

Now monitoring the FC loss so I can figure how much I need to add each day. It is currently looking like I am losing FC of about 0.6 per hour (this is in bright sunshine with 3 of us swimming). Current FC is 10.5 and I am aiming to let it drop to 7.0 (target for CYA of 60).

Question is: once I get to 7.0, if I know I am going to lose FC 0.6 per hour through the day. We currently have almost 14 hours of daylight and the pool will be in full sun for most of that (assuming the weather). So 14 hours with an FC loss of 0.6 would give me a total loss for the day of 8.4. That equates to 200oz of 10% bleach per day - seems like a lot?

I am going to continue monitoring the FC daily for a while to get a good feel for the loss versus weather and swim load etc

In the meantime, if my FC gets down to 7 (and I certainly don't want to get below 5) should I just add the 200oz which would raise the FC to 15 or so, this based on an expected loss of 8 through the day.....hope that is clear

Just not sure the best way to manage the FC level without it dropping too far.....

Thanks
Dave
 
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