New to Chemical Testing / FC not registering

[wjthomas42]

I am about to cancel my pool maintenance company and did my first chemical testing tonight which resulted in some concerns

1) When testing for FC, the pink solution never changed to colorless. I was doing the test with 10 mL of water and added 30 drops then tested a second time and added 20 drops and no change in color.
2) CH turned purple and not red when doing the test. I was testing at dusk with a headlamp, but definitely looked more purple than red.
3) What do you do with the tested solution? The manual says not to dump back in the pool.
4) I have 1 gallon of muriatic acid, 1 gallon of bleach, 1 box of borax, PVC gloves and safety glasses. What other chemicals or safety items should I purchase to keep on hand?
5) Any suggestions on a good brush and pole to purchase?

Results:
pH 7.4
TA 50-60
CYA 80-100


16,000 gallon pool/spa

 

[atttech-2]

It is possible the pool company has the FC sky high. Try adding 5ml of pool water and 5ml of distilled or bottled drinking water and run the test again whatever result you get your FC is approximately double.

For the CH test it sounds like what is called a fading endpoint. Take a look at the extended test kit directions in Pool school for additional steps you can try.

Safety gear is not a bad idea when dealing with MA but I must admit I don't use it.

I throw my samples down a sewer clean out that is near my equipment pad.

As for pool brush I can't say enough good things about the wall whale

 

[duraleigh]

Chances are very good your FC is Sky high.

Your CYA is certainly too high

The sample testing solution is minuscule. Use common sense but it is essentially harmless.

Is your CYA 80 or 100?

 

[wjthomas42]

What is the biggest negative (besides cost) to high FC levels?

I'm new to testing and was doing the black dot test for CYA and it was probably closer to 80

 

[mgmoore7]

I would do the TC test again and keep adding the drops. At some point it will start to change color. It does not go from red to clear in one drop. It leads up to it. You just may not have got there yet.

When I recently did a SLAM, I had to add 65 drops since I overshot the amount of Bleach to add and that made my TC 32.5.

 

[Catanzaro]

Please take 50% pool water and 50% tap water and test again for chlorine. Do you have a speed stir? If in fact, you believe your FC is sky high, you may want to fill a vial with 20 ml. of tap water, another vial with 10 ml. of pool water, mix properly, then place only 10 ml. in another vial and test again. If your FC is really high, your testing should show results with a lot less drops.

You may also want to call the pool maintenance company and ask them what they were adding to the pool, and how often. Most companies ask straight shock, either increasing your CYA or CH. Something is off. Please keep us posted and welcome to TFP.

 

[atttech-2]

What is the biggest negative (besides cost) to high FC levels?

You can live with a High CYA level and let it come down from splash out and draining a bit as you get rain you just have to be very diligent to make sure you don't get any algae while it's high.
The day to day cost is not much different with a high CYA level once you get to your target FC level. Your FC consumption will still be 1 to 3 PPM per day. The issue can be if you run into an algae bloom should you let your FC drop below the recommended level. Then you will need to SLAM and at that point you will have to use a whole lot more chlorine than those with lower CYA levels. You may have already seen the Chlorine / CYA chart but if not take a look you will see what I mean about the needing a lot of chlorines should you need to SLAM at your CYA level.

 

[pooldv]

 

[wjthomas42]

Thanks so much. What's the implications of too high FC levels?

 

[atttech-2]

Thanks so much. What's the implications of too high FC levels?

Not much unless we are talking about a FC over SLAM levels. Some even swim while SLAM-ing assuming they are just clearing a minor problem not dealing with a swamp. At higher levels bathing suits will not last as long but would have to be a constant condition not a one time overshoot. The farther you get outside of the recommended FC for your CYA the faster the FC will burn up so if you overshoot it usually will only stay that way for a day or two.

That is also why the SLAM process requires so much attention your FC is beyond the protection of the CYA being burned up by the sun while consuming organics at the same time so the level comes down quickly sometimes requiring additions hourly.

 

[wjthomas42]

We have had lots of rain in the Houston area recently. Would be the pool maintenance company intentionally put high FC levels prior to lots of rain?

 

[atttech-2]

They might but if they did it's ill advised.

1" of rain in a 15' X 30' pool is about a 2% increase in water assuming you don't have an overflow and it is not like that rain is 100% organics that has to be oxidized. So why increase the FC several times what is needed for a dilution factor that is statically insignificant. It is more likely they only visit once a week and they try to blast it sky high in hopes it will last till they get back to do it again. Problem is FC does not get consumed in a linear fashion once you are outside the level that the CYA can protect it burns up very quickly.

 

[duraleigh]

What is the biggest negative (besides cost) to high FC levels?

Chlorine in amounts greatly in excess of what we suggest is very corrosive. It can quickly damage exposed metal surfaces, it can fade swimwear and it can permanently damage vinyl liners.

 

[wjthomas42]

My pool maintenance company came yesterday (Tuesday), and I attempted testing FC again today (Wednesday).

1) 50:50 pool: tap water. the solution didn't change to colorless
2) 5mL pool: 20 mL tap water. the solution didn't change to colorless

Tested CYA and it is 50-55

I will call the pool company tomorrow. I will ask them the targets for the different components. Anything else I should ask?

 

[Catanzaro]

Based on a diluted CYA test (Which I am assuming you did), your CYA is between 80-100 (say 90). This is a little high, but can still be managed. Which tests did you perform with # 1 and # 2 ? If this for the FC? If # 2 is 1/5th pool water and 4/5th tap water and the solution did not change (please explain how many drops or exactly what you did?). Thank you.

 

[wjthomas42]

The CYA was not the diluted. #1&2 are for FC

I did 50 drops for the 5mL pool : 20mL solution

 

[Catanzaro]

Results: pH 7.4 TA 50-60 CYA 80-100

Originally, you tested:

The CYA was not the diluted. #1&2 are for FC I did 50 drops for the 5mL pool : 20mL solution Tested CYA and it is 50-55

Your CYA seems to have dropped significantly in a short period of time? Why?

Because your FC is so high!!!!, you may just want to assume you will loose 2-3 ppm per day and test when you suspect the FC range is near 10 or so, etc. This way you do not waste reagents. 50 drops with a 1/5 ratio puts your FC at over 100 ppm. Something just does not add up. What do you believe your FC reading is? Maybe I am missing something.

 

[wjthomas42]

I don't think CYA dropped that much in that timeframe. It's probably that I'm new to the testing. I would expect 50-60 is the current range and the last reading was overstated.

no clue the FC level as never turned colorless

 

[wjthomas42]

I tried testing the FC again today with 10 mL pool water and did 30 drops and it didn't change to colorless. The pool company came on Tues, and today is Sunday. So it has been 4 full days and surprised didn't see a big drop

 

[Catanzaro]

I tried testing the FC again today with 10 mL pool water and did 30 drops and it didn't change to colorless. The pool company came on Tues, and today is Sunday. So it has been 4 full days and surprised didn't see a big drop

To save reagents, every day If you have the Taylor K-1000 Kit with FC/BR on left (yellow) and PH on right (red), test with this. If you continue to see bright yellow, then you are fine. It is a good investment for like $10 on Amazon if you do not have one. Not too familiar with K-2006 Kit, but assume very similar. Also, I believe the FC test will change colors if the chlorine reading is real high.

QUOTE]The pool company came on Tues[/QUOTE] We here at TFP rely on our own testing and taking care of our own pools. Are you using the pool company for chemicals? What exactly are they doing? Recommend highly against any type of pool maintenance service.