First time testing with TF100

[JimB]

Hi, all. I posted why and how I got here under 'Just getting started' so I won't go into that again. First test with TF100 today.
A little history of this year's trials and tribulations. Open pool early June-looked good-topped it off and everything hooked up. Took sample into local pool store-walked out with three pages of instructions and $125 worth of chemicals. Keeping up with sweeping, brushing and backwashing. About three weeks later-GREEN. Took sample to a different (national, I think) pool store. Much happier with them. Walked out with National Chemisty 'Phosfloc,' four gals MaintainProPool 'Liquid Shock,' Litehouse 'slow dissoving chlorine sticks' and paper style test strips. (I should add here that they did not 'push' any chemical on me except for the Phosfloc and two gallons shock recommendation. The other stuff was all my decision.) Added two gals shock and two lbs floc. It took three or four days vacuming to waste but got it all. Pool was slightly cloudy but good looking. About ten days ago, daily test showed no chlorine so I added a gallon of liquid shock. A week ago added three oz. BioGuard 'Polysheen Blue.' Two days later, this is the most crystal clear it's ever been. Sometime since opening I did add BioGuard algae treater but I don't remember when. Been keeping up with brushing and vacuming.

Test results taken today around noon
Daily test kit - total chlorine showed 5 (bright yellow) - pH showed 7.2
TF100 - FC 2.5 - CC 1.5 - TC 4 - T/A 70 - CH 180 - CYA 20 - pool temp 85

I'm sure some of this is subjective. Ex. for CH the sample turned pale blue at 18 drops. I added two more drops and a bit bluer. Similar on other tests.

So, I guess my question is, What do the experts here think of what I've done up to today and what do you think of the results of today's test? I'm still working my way through pool school. Sometimes I have to read things three or four times to get it to sink in. I do have a question about my filter but it can wait.

Thanks in advance,
JimB

p.s. I forgot about going to the Pool Calculator-just did-don't fully understand-Back to that topic in Pool School

 

[JasonLion]

The big question is your CC reading of 1.5. That might be testing error. When doing the full FAS-DPD chlorine test you need to make sure the sample goes completely clear when measuring FC, before you add the five drops that turn it pink again for CC. If you stopped a little early and the sample was just slightly pink the CC level would read higher than it actually is.

If your CC level is really 1.5 you need to shock the pool.

Your CYA level is a little low. If you are still using the slow dissolving sticks then you are fine, they will bring up the CYA level over time. If you keep using the sticks, the CYA level might eventually get too high, but probably not this season. If you are out of sticks and are just using the liquid "shock", you should add some CYA.

If you are using the sticks, you should raise your TA to around 100-120 with baking soda. The sticks are mostly trichlor, which contains chlorine, CYA, and lowers PH. Keeping TA around 100-120 makes it easier to keep the PH in range. If you aren't using the sticks any more then your TA is fine.

 

[JimB]

Thanks for your reply. My son wanted to see how the test kit works so we did it again at 7:10pm EDT.
Even before I posted this a.m. I was wondering if I had the colors as far as they go. For example, you mentioned the test for CC. It may have been a tinge pink when I called it. This time is was clear with one drop. As for the T/A test, how red is red? It did turn redder than this a.m. at 8 drops but I added a couple more, just to see what happens. It didn't darken noticeably. The same thing for CH. Between 22 and 25 drops it did seem to darken a bit but adding up to 5 more drops, no noticable change.
My son said that the test kit company should have a color chart so we had somethng to compare to. Would that work or is red/blue from one pool different from red/blue when testing another pool.

The numbers this time: FC 4 - CC .5 = TC 4.5 - Ph 7.4 - T/A 80 - CH 250 - CYA 30.

The water still looks good so I'm not going to add anything until I finish the pool school and test again.

The main thing I'm still confused on is the differences between FC and CC and how they inteact. Hopefully the school will enlighten me.

Thanks,
JimB

p.s. I just reread you first paragraph and the light bulb blinked. It's not on all the way but glowing brighter.

 

[JasonLion]

For the FAS-DPD chlorine test you want the water to go completely transparent, no pink at all.

For the TA and CH tests you are looking for a color change, it doesn't really really matter what the particular colors are. Once the color starts changing you keep adding drops till one drop doesn't change the color. The final drop, which doesn't change the color, is not counted. The colors will usually be the same, but can vary at high FC levels.

Since your CC level is 0.5 or lower there is no problem and no need to shock.

FC is free chlorine, the active disinfecting form. CC is combined chlorine, chemicals formed when chlorine has partially broken down a contaminate. Adding additional chlorine will break down the CC further till it "vanishes". FC helps keep your pool clean. CC above 0.5 causes irritation and bad smells.

 

[JimB]

Thanks again, Jason. I think I'm getting there. I have a bit of a thick head and sometimes it takes a while before it sinks in. That was the best explanation of FC vs. CC vs. TC that I ever received.

JimB

 

[JimB]

It's been a eight days since I started using the TF100. Pool has been nice and clear. It hasn't been used. I have to backwash everyday??? I added two inches water due to loss by backwashing and lack of significant rain. (We haven't had a decent rain in around two weeks.) It does need a brushing and I'll do that after I post. Some questions about using the Pool Calculator.

First, the test results
Temp-78 - FC 2.5 - CC 0 - ph 7.4 - T/A 70 - CH 180 - CYA 30

I plugged the # in to the Calculator. It says to add a 42oz. of 6% bleach. What difference does 'jug size' make in that calculation? What does it mean when adding something by weigth vs. volume? Is volume like using a measuring cup? I usually use a kitchen scales for weight measuments. Maybe I missed it somewhere but does the calculator all effects into consideration when giving suggested amounts? i.e. borax affecting ph and ta as well at baking soda affecting the same things? If I understood Pool School CH isn't a big concern for vinyl liner pools. Yes? No? Do I really need to add 160oz/weight of calcium chloride? Also the 18oz stabilizer...I'm thinking of just tossing in one or two chorine pucks to the skimmer and let that handle the CYA and FC adjustments? Am I off-base?

Sorry for all the Q's but thanks for all of the A's.

JimB

p.s. I came back here and edited amounts suggested because I forgot to specify #gallons.

 

[JasonLion]

You don't normally need to backwash every day. Is your filter pressure rising very quickly?

Jug size affects the comments that appear in the status area when you mouse over the number of oz. For large amounts of bleach, the status area will show you how many jugs of bleach you need to use.

Weight is measuring on a scale. Volume is measuring with a measuring cup.

No, the Pool Calculator does not take all effects into account. Each level is treated separately.

No need to add calcium. You do need to make sure it doesn't get too high.

Trichlor pucks will add both chlorine and CYA, but they add CYA fairly slowly.

 

[frustratedpoolmom]

Trichlor pucks will add both chlorine and CYA, but they add CYA fairly slowly.

Add they are acidic and will lower your PH so keep an eye on that if you decide to use them.

 

[JimB]

Aug 4th test results--FC 1.5; CC 0; TC 1.5 (-1.0 change from ten days ago); pH 7.5 (+.1 change); TA 70 (no change); CH 150 (-30 change); CYA 30 (no change); temp 79 (+1)

I've had to add about 4 inches of water due evaporation loss. I think I've only added one chlorine stick immediatly after the last full test. I'm still trying to learn and understand but the light bulb hasn't fully lit yet. The pool is still clear and I've had no problems since the green in June.

Jason, still the same situation with the filter. The pressure gauge doesn't change at all but when I backwash, the site glass will show dirt until it runs clear. It doesn't change when I vacum, either. I had to put a new gauge on this year. Is this part of the reason---My old pool store (the one I liked), said that I didn't have to change the sand every year. He said that the sand builds up something good that I'd lose if I changed every year. He said that he hadn't changed his sand for eight years and he's had no problems. After reading 'pool school' I see why sand needs to be changed but is it necessary every year? Mine is on it's third year.

A ? about TA and pH. My brother's pool vinyl liner is wrinkling. I think he said that his pool place said that's because of low TA. Yes/no? I have a call in to him to check my memory. I've notice a couple wrinkles starting in my pool's liner.
The calculator says to add 70oz baking soda. I'm going to add that plus the chlorine it suggests. I have some stabilizer (BioGuard Stabil 100) left over so I'll add that up the the amount suggested. If I have that much.

You guys are great, Thanks again.

Jim

 

[JasonLion]

Your FC level is too low for your CYA level. You should try to be sure to never let FC go below 2. Other than that your numbers look fairly good.

Some people never change their filter sand. People who do change their sand only change it once every five to seven years.

Low TA leads to the PH getting out of range very easily, which can damage the liner. If you are using trichlor, it is important to keep TA at 100 or higher to keep the PH from getting too low.