Help with high combined chlorine!

[frogabog]

Here's some good reading for you (you really don't need to read anywhere else). You're not fighting CC, you're fighting organics. The last link is what you will want to use in the future to determine how much to add. If you don't have/use a smart phone or tablet, you can always use the browser version of Pool Math.

ABCs of Pool Water Chemistry
FC/CYA Levels
SLAM Process
PoolMath

 

[Mr. Scott]

No place for that much water to go in a short period of time. Especially with having a record rainfall this year, water table is really high. Getting more water is easy.

 

[TexasPool128]

Your high CC is the result of all that chlorine attacking and killing something organic. When there's nothing to kill, your CC will go back to 0.

Idk why you didn’t post this in my thread but I’m glad to see it here. When I stated CC was from chlorine killing algae (organic), I was “corrected” and told I was wrong and that CC is from chlorine reacting to other chemicals. (See pic below of post)







Glad I wasn’t losing my mind and I was correct!

 

[frogabog]

I believe there's a chemical change that is the byproduct of the algae being killed. Chlorine combines with ammonia and nitrogen, creating chloramines. So what he said was true. It's just a little less specific to say it's the result of chlorine killing algae or biologicals. Nitrogen is the results of biological demise or rather, decay. So... I'm no chemist. It's accurate enough for purposes of general understanding what's happening in the water to say either way, I believe.

 

[Donldson]

Yeah, what I said was true. And it still is, no matter how much one wants to believe it isn't.

For reference, a quote from JamesW:

Many people doing a SLAM for algae expect to see CC as part of the process.

However, algae should not react with chlorine in a way that creates CC.

CC is a result of chlorine combining with something like ammonia where the chlorine is still in the active +1 state.

For the most part, the reaction of chlorine and algae is an oxidation reaction with the chlorine being reduced to inactive chloride in a -1 state.

If CC is present, that usually points to some contaminants in the water.

Until the OP's chlorine level drops I would suggest we stop talking as if the ColorQ is giving accurate results. Not that I would suggest ever trusting a ColorQ to be accurate, but that's a whole other discussion.

 

[JamesW]

You can get some CC during a SLAM for algae, but it's typically minor and short lived. Many times, a SLAM doesn't produce any CCs.

High CCs are mostly due to ammonia type compounds.

 

[Mr. Scott]

Sorry for the delay, I am going to pick up a FAS-DPD test kit at a local pool store in the morning and run tests. Also I can pick up some sodium thiosulfate for 75 cents a pound, should I get some?

 

[mknauss]

Unless you have an exceptional pool store, you will need to order the FAS-DPD online.

 

[tabitha_599]

Taylor Test kits are what is recommended here at TFP. I ordered mine on Friday and it arrived yesterday so they are fast. You can order at TFTestkits here. The T-100 seems to be the preferred kit if your budget can afford it. The people in this group are a wonderful resource. Good luck to you.

Sorry for the delay, I am going to pick up a FAS-DPD test kit at a local pool store in the morning and run tests. Also I can pick up some sodium thiosulfate for 75 cents a pound, should I get some?

 

[Mr. Scott]

Taylor is what I am getting, store doesn't have it in stock despite their website saying so. However, they can get it for me Thursday. I will get a OTO kit just to see what my total chlorine currently is. My water level was a little low so I did add some water.

 

[Mr. Scott]

I used a Walmart OTO kit and some sodium thiosulfate to knock the TC down to about 12. Just completed the Taylor K-2006 test today here are the results.

FC is 5.5

CC is .5

PH is 7.1

TA is 100

CH is 310

Having trouble with the CYA test as the instructions are pretty vague. Adding liquid to the dot just disappears is pretty subjective. All I can say is the water in the test tube is somewhat cloudy at the 40 PPM mark and even more cloudy at the 30 mark, but the dot doesn't really disappear. A little confused by the CYA test.

 

[mknauss]

When you do the CYA test, try this next time.

Once you have your solution ready, back to the sun, etc. Fill the vial to a line, say 80, lower the vial to your waist level and glance for the dot, you see it, add solution to the 70 line, glance, see it, repeat until you no longer see it with a glance. Then use the CYA value one step above the line you read. So if you stopped at 50, use 60 ppm CYA.

The vial is in logarithmic scale. So it is not viable to interpolate between the lines. Just use the whole numbers, such as 50, 40, 30, ....