1st test with the TF100, high Calcium Hardness, Drain?

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D

DoAsFan

0
Sep 21, 2012
43
Foster City, CA
I've been a pool owner for about 6 months now. The water was green and cloudy when I moved into the house, so I opted to have the original pump and filter replaced back in January, and the pool had been clean ever since. I've been putting off testing the water, and just blindly dumping in a half gallon of 12% chlorine every week.

Well, now that the weather has warmed up, the water has taken on a greenish hue again. Not totally nasty, since I can still see the bottom, but I figured it was past time I started learning the chemistry.

TF100 results:
FC = 0
Ph = 8.2
TA = 120
CH = 440
CYA = 0

Based on Pool School and The Pool Calculator, sounds like step one is to drain about 40% of the water. My main drain and skimmers are all tied together, so I'm off to Home Depot for a submersible pump. I'm pretty close to sea level (on landfill) and not quite sure how to determine what the groundwater level water for my area is. The USGS site shows 22 feet Below Land Surface from about 15 miles east of me.
http://groundwaterwatch.usgs.gov/countymaps/CA_001.html
Safe to start pumping?
 
CH at 440 is livable if you need to. Before you replace any water it is important to find out your fill water CH level. If your fill water level is high (80+) you should leave things alone for now. If fill water CH is low, then don't risk the pool floating and instead just replace a foot to 18" at a time.
 
Thanks Jason!

I performed the CH test on my fill water and got 220. My water district reports an average of 13 ppm, ranging from 3-24. Not sure what the units for our test are. The water was clearly pink after mixing in the 5 drops of R-0011L, so there is definitely calcium in there.

Just read thru the extended directions you posted and realized I should be swirling after every drop of R-0012. The laminated instructions don't indicate mixing at all, which blows, since now I've used up 66 drops of the reagent! Oh well. Next time I'll do the 10mLx25 test instead.

Anyway, I'll follow your advice and drain out a foot for now, just to get that average down. So next steps are baking soda for pH, stablizer for CYA, then bleach?
 
CH test is ppm. Is your water from the same source as the numbers you posted...ie is it the same well/water source? Definitely use the 10 ml sample in the future, you really don't need better accuracy.

Draining is not going to do you much good at that high of CH fill (unless you do a lot), so don't do a drain/refill for now.

DoAsFan said:
So next steps are baking soda for pH, stablizer for CYA, then bleach?
Click to expand...
Your ph is high, so lower that to 7.2-7.4 using Muriatic Acid (MA). You may need to do this multiple times, since ph over 8.2 can read as 8.2. Dose with MA, leave circulating for an hour then test agian and adjust again. Do this until you ph is around 7.5. You will not need baking soda.

Next, you need to do the shocking process. After you get the shocking process started, then in parallel you can get the cya level up to 20 ppm.
 
Hard water is not surprising where you live.

Be extremely cautious about draining any water. The water table in Foster City is barely beneath the pavement, and changes with the tide. You run an enormous risk of floating the pool and snapping underground plumbing if you empty too much.
 
I'm not sure how this thread glided right into replacing water. I would leave it alone for now. CH of 440 is quite manageable.

What is FAR MORE IMPORTANT is that you get your pH down into the low to mid 7's and keep it there. Secondly, you need to shock your pool once your pH is down. Both of these items need attention before you begin to worry about CH.
 
Got it, CH is just not important for now. Not draining.

I thought pH and my brain immediately thought baking soda, but I see that I need muriatic acid instead. Thanks to all for the advice.

Poured in a gallon of 14.5% and tested an hour later. Now pH is at 7.2. That was easy!

Now onto my first attempt at shocking.
1) Filled two socks with about 2.5 lbs of dry CYA stabilizer/conditioner and dropped them in my skimmers. I targeted 20ppm, but wondering why not aim for 30-50 (per Pool School recommendations)?
2) Poured in 2 gallons of 10% chlorine to target shock FC of 10.
3) Brushed all around, and leaving the pump running.

So since the test kit only goes to FC 5ppm, I'm checking FC hourly until it drops to a measurable level, then aim for shock level again until the water looks good, then perform the OCLT?
 
Ah, so THAT'S what all the other bottles are for! I was so excited after running through the "daily" test instructions, I totally overlooked the FAS/DPD instructions. Sorry, absorbing a ton of great info all at once... but not all of it staying in there.
:hammer:

Just reviewed the abbreviations/definitions doc again, and I'm beginning to understand the difference/relationship between TC, FC, and CC. Also just watched the video for the FAS/DPD test. Good stuff.

Pool was looking better this morning, clear but still green. I'll test tonight and shock accordingly. Thanks!
 

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After raising FC to a targeted 10 on Sunday afternoon, here are the results from Monday 5pm:

FC 5.5
CC 0.5
pH 7.2
CYA should be at 20 based on what I put in Sunday, and I'm assuming CH and TA haven't changed

CYA chart says 10, but calculator says to shock to 11, so I added 1 gal of 10% chlorinating liquid at 5pm and tested at 7pm:
FC 12.5
CC 0.5

At 9pm:
FC 13
CC 0

I'm curious about the 0.5 uptick in FC results. Is this possible or more likely just inaccurate testing on my part.

After the shocking is done and the week wait for CYA is over, should I work on raising CYA and pH to the "recommended levels?"

BTW, I've got the pump running day and night at the lowest speed (<1000 rpm) during shocking, but bumping the speed up to 2700 rpm while brushing and dosing with chlorine.
 
Likely the 0.5 was just testing error ... the test is good to +/- 10%.

In a week, test the CYA again and adjust up to around 30ppm. Then after another week you can raise it some more if you want.

You can test and adjust the pH whenever the FC happens to drop below 10ppm.
 
5pm
FC 9.0
CC 0.5
ph 7.2

Shocked with ~64 oz 10%, brushed, ran the Polaris for an hour

9pm
FC 11
CC 0.5

Water looks clear green, that is until I brush. Then I get clouds of dark green. Should I be pumping at a higher speed to accelerate the shock process? I know, POP, but am I hampering the progress by trying to save on electricity, or is it just a matter of letting the chlorine work at its own pace?
 
Update on the past few days.

Wednesday
7am: Added 64oz of 10% liquid Cl on my way out of the house.
5pm: FC 11.5, CC 0.5
I drained the spa, removed the eyeballs, and scrubbed with a toothbrush.
10pm: FC 8, CC 0.5
Added 64oz 10%, target of 11ppm

Thursday
5pm: FC 6.5, CC 0.5... FC WAY down
Added 128oz 10% targeting 11.5ppm
Toothbrush again, inlets, skimmers, and UWF. Some nice dark green and BLACK gunk came off.
11pm: Added 64oz 10%, aiming to raise FC to around 14.5

Friday
7am: FC 15, CC 0.5... seems like it's starting to hold

5 days into shocking, water has just barely a little bit of green to it. Really struggling to get the last bits of dirt out with my Polaris 3900 Sport. I really hate that thing. But I have a pole attached garden hose/vac device arriving today! Plus a spring powered airsoft pellet gun to discourage the ducks that keep pooping in the pool. I may just break down and order the 3900 upgrade kit. Also considering taking apart the booster to see if its jammed or the impeller is worn.

Looking forward to testing CYA this weekend also.

Thanks all for letting me :rant:
 
Sunday 7pm
FC 2
CC 0.5
pH 7.4
TA 110
CH 190
CYA 30

FC level held overnight, but seems to drop about 2ppm during the day.
pH went up by 0.2 suddenly. Was consistently 7.2 all week, not sure what caused this.
CH dropped a bunch this week. Most likely that I tested poorly the 1st time. Didn't mix each drop.
CYA was around 27. Stabilizer socks are not yet fully absorbed.

I'm thinking of raising CYA to 40, so that my daytime FC will hold better, at least until I can get a solar cover. The chlorine costs are starting to add up! At least I'm done shocking, I hope. I may try a few trichlor pucks in a few weeks over a long weekend, for +CYA and +FC.

Should I be concerned with my CH at 190?

Thanks!
 
pH climbs because you have slightly high TA. Just keep adding acid when pH gets to high and it will fix itself. Nothing to worry about.

Losing only 2 ppm per day is excellent!

Don't worry too much about CH. It will go up fast enough when you start refilling your evaporation losses.

What cost? I'd guess maybe...maybe.. a buck to a buck and a quarter a day for chemicals. Under fifty bucks a month. Less if you cover the pool. Go loiter around a pool store some day and watch the people leaving. Odds are they'll have help carrying all their purchases out - one of the clerks will gladly load up a hand truck with three or four hundred dollars worth of plastic buckets.

It's worth shopping for chlorine. Sometimes Costco, sometime a hardware store, and amazingly, sometime a pool store will have the best price per %-oz. It might be worth making a call to one of the HASA dealers near you - I get refillable jugs of 12.5%.
 
Richard320, thanks for the tip! Home Depot is the cheapest of the box or grocery locations. I figured pool shops would charge a premium, but I'll check out the two nearest me and compare.

JohnN, just checked the socks and they were just puffed up with air. I'll check the CYA level again before using the trichlor in a couple of weeks.

TC is still reading at about -2ppm a day, and the water is looking good enough to drink!
pH however just clocked in around 7.7. It held at 7.2 for a whole week, then suddenly shooting up? Sounds like I'm ok up to 7.8, and I've got a gallon of 14.5% MA handy, but just very curious what could be causing the pH to rise so suddenly.
 
Your TA is a little on the high side contributing to your rising pH. As you use acid to bring pH down your TA will fall as well.

Any aeration will also contribute to rising pH like your spa.

Congrats on your successful shocking, now don't let the FC drip that low again. ;) You simply MUST keep your FC above the minimum for your CYA at all times. You will "get to know your pool" in terms of it's FC usage and pH and will be able to tell if something's awry just by looking at it or noticing an unusual trend.
 

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