First results. First steps.

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BS_LM

Active member
Aug 11, 2019
30
Twin Cities, MN
Received TF-100 yesterday and started testing this am after previously using up some dichlor with the intent of actually seeing some chlorine and bringing up CYA(based on very low values of both per our pool store and test strips). As evident from the testing below, didn’t need the CYA, and we have decided to live with the slightly high level for now rather than replacing water. Based on the results below with the TF test kit, I am now starting a SLAM after adding Borax to address a low pH(from test strips and store, I believe the pH has been fine until the last 2 days and 8 cups of dichlor).


First result from TF-100:

Water: slightly hazy
FC: 1 (0.5?)
CC: 3.5
pH: 6.8
TA: 260
CH: 500(1000?-stopped at 40 drops, lavender color after 15-20 w/o further change-never blue)
CYA: 85 (maybe only 80)


After the above and the addition of 512 oz of 10% liquid chlorine and 325 oz of Borax, I obtained the following:

FC: 1.5
CC: 3
pH: 7.2


I then added 869 oz of 12.5% liquid chlorine and am off in moment to recheck the FC, CC, and pH, I hope to reach a FC of >30 and maintain it until SLAM complete. Meanwhile working on the TA by running the cleaner as my aerator.


We have an autocover that is closed about 90% of the time, so I expect that chlorine degradation by sunlight should be limited.


Input welcome.


-Bryan
 
Depending on your water source, the CH in your pool may be quite high, so your results of over 1000 could be true. PM me for what I know about hard water in the twin cities, if you want.

Do you have a SWG? A CYA of 90 (we round up by 10s), is high for our part of the country. You might want to drain/refill to reduce to 40. But at this point in the season with impending drain for winterizing in October, you may not want to do that and instead work with what you have.

You need to get some sun on the pool to help burn off the CCs. (I know this week is supposed to be pretty cloudy, but that may work to your advantage.)
 
Well, that was disappointing. The latest numbers, following 7 gallons of 12.5% liquid chlorine, follow:


FC: 1
CC: 5
pH: 7.2


I will have to pause the SLAM till tomorrow. Right or wrong, I have left the SWG going throughout.


@gonfishin. We certainly see minerals/calcium buildup around shower heads, faucets, etc, but it has never been apparent in the pool. I think we may have misinterpreted the color change and thus put in way too many drops. I will see the next time I run the CH, which may not happen until this coming weekend.


Yes to the SWG. From our last in store reading, we were under the impression that the CYA was 10, and were expecting the need for stabilizer. The TF-100 test suggests otherwise. For various reasons, we are not anxious to drain and replace water right now, though I am concerned that with the 80+ CYA, we may be buying an awful lot of liquid chlorine.


I have not heard of getting some sun to burn CCs, but I will look on this site for a reference(s). I am trying to get my head around the CCs. As an example, why would the CC go up from afternoon to evening, after the addition of 11 gallons of liquid chlorine over the course of the day?


I haven’t looked a week ahead, but I hope the clouds you anticipate here in MN this week dissipate by the weekend. We are hosting a family gathering(pool!).


-Bryan
 
The CC of 5 is very concerning. Have you added algaecides or other pool store potions in the recent past?
 
We used a Clorox branded dichlor on Friday and again Yesterday as we were aware of the very low chlorine(based on test strips) and not terribly concerned about increasing CYA, as a pool store sample suggested CYA of 10. One week ago, we added Proteam Phosfree(I believe I have the name right), again based upon pool store sample indicating very high phosphates. Found this site in the process of trying to figure out why the phosphates were so high. Previous use of Zipchlor. Nothing else comes to mind at the moment.
 
Zipchlor is dichlor too. No wonder your CYA is so high.

The CC being that high is implying ammonia type compounds in the water. Or the use of MPS, non chlorine shock.
 
Until coming to this site in the last week, I did not recognize the CYA challenge associated with dichlor use. And then when I was under the impression of a low CYA, I thought it a good opportunity to use the dichlor on hand while searching for local sources of liquid chlorine. So much for thinking. :)

I am learning now that, at the advice of the local pool store, my other half added about two quarts of an algecide about one month ago. I don’t know what type of algecide.

-Bryan
 
Hello and Welcome to TFP!!

I didn't see you write why you were in the SLAM process. What does your water look like? How does the pool smell? Have you been able to get a chlorine reading prior to today? When did you open your pool for the season?

Don't add any other chemicals to make adjustments unless advised to do so. That includes purposefully running aeration. Only liquid chlorine for now.

To confirm your testing methods:
When testing for FC, you use 10ml of water, then add the R-0870 powder, then the R-0871 drops until the solution goes from pink to clear. Then immediately (not waiting more than 30 seconds) adding 5 drops of R-0003, then using the R-0871 drops until the solution goes from pink to clear again? With a CC of 5, you are using 10 drops the second time after you added the R-0003? Making sure to constantly swirl while you are adding the drops.
 
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Water is slightly hazy(deep end is not absolutely clear). Pool smells fine. The only chlorine readings before today were from the pool shop, or, more commonly from test strips. Opened the pool in April, but payed little attention to it for a month due to low temps(air and water-we typically let the water temp gradually climb up to upper 60s before turning on the heater). Lori recalls that she was sold much more product than usual at the beginning of this season. I am unaware of the details, but this could have a bearing on mknauss’ question above about what has gone into the pool. I was considering the SLAM because of the hazy water, but the first CC showing 3.5 decided it.

Got it.

I have followed the FC testing pretty much as you described. There may have been minor delay when moving from reagent to reagent.
 
I am HOPING the cc of 5 is just showing us the chlorine did it's job.

The big drop in FC does show there is something in the water. My guess is you were right on the edge of a full blown algae bloom. You got the test kit just in time to stop it.

Please leave the cover open during the night so the CC can outgas. That might help with the CC levels.

Kim:kim:
 

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Opened the auto cover this morning so the CC can outgas. Water is clear. Test results as follows:

FC: 2.5
pH: 7.1

Should I continue to add liquid chlorine to raise the FC and/or add more Borax to raise the pH?

Thanks in advance for recommendations.
-Lori
 
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Evening update-Lori thought we were aiming for a FC of 7, rather than SLAMming to 33, and so she added about 1.3 gallons of 12.5% liquid chlorine this morning. The result:

A crystal clear pool!
FC: 0.5
CC: 3

In response, she added the last of our liquid chlorine supply-3.7 gallons of 12.5% liquid chlorine. Back at it tomorrow, hopefully we can find enough chlorine to SLAM.

-Bryan
 
We estimate that 6-7 hours passed between the am chlorine and the pm tests. Another trip to Menards tomorrow for more chlorine! Over the last 4 days, we have added 7 gallons of 10% and 12 gallons of 12.5% liquid chlorine(and about 8 cups of dichlor)!
-Bryan
 
Today's test readings:

FC: 0.5
CC: 2.5
pH: 7.0

Sparkling clear water. Kept autocover open all day so the CC can outgas. Completed slamming with 9 gallons of 12.5% liquid chlorine. (no more dichlor for us!)

@frogabog ....and the best advice ever was adding the adult beverage to the regimen!
-Lori :)?
 
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It's good to see the CC is coming down and you have clear water. But the SLAM process continues until CC is 0.5ppm or less.
Clear water means that the water body isn't cloudy, no visible algae AND there is no white or brown sediment that occurs after a while.

Can you run a test, after you add your dose of chlorine, let the water circulate for 30 minutes and retest FC. You can use the 5mL water sample to save some reagents for this test (and only this test). Report back the intended FC level and the tested FC level.
 
We can certainly repeat the FC test 30 minutes after adding the next chlorine, though it was my impression that more time is needed to allow for circulation to mix the chlorine evenly. As to the intended FC level, we are aiming to SLAM to FC 33 with CYA of 80.
-Bryan
 
30 minutes is generally considered plenty of time for any additions to mix with the water. As long as the pump is running.

I feel like it's possible that the cover is what could be running up the CC. It may take a day or so for that to sort out. Are you closing it at night still? If so, leave it open.

Also, are you running FC up to SLAM level once or twice a day or are you testing and re-adding multiple times a day?
 

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