New to using a real test kit. (ColorQ Pro 7)

Chlorinating, maintaining the right chlorine levels,
chlorine problems. Dichlor, trichlor, cal hypo, bleach,
granules, chlorine pucks and chlorine sticks.
Tommyt
Pool Newbie
Pool Newbie
Posts: 4
Joined: Wed 01 Jun, 2011 06:48
My Pool: 13,000 gallon - Fiberglass
Sand Filter/2HP pump
Stamped concrete deck with custom tile
3 inch chlorine for sanitizing

New to using a real test kit. (ColorQ Pro 7)

Postby Tommyt » Wed 01 Jun, 2011 06:59

Problem:
Got a real test kit and dumped the test strips, but need help with ALL the new data that I'm getting. Pool looks great, but it seems that my FC/TC are out of wack and I may need to shock my pool.

Temp: 84
FC: 5.53
TC: 6.38
pH: 7.2


My pool: Fiberglass
Pool chemicals: 3 inch tablets
My pump & filter: 2 hp/Sand
Other info:

I'm also trying to find an ideal TC/FC for my pool. a Google search finds a ton of mis-information.

APPECIATE ANY HELP.....


chem geek
Pool Industry Leader
Pool Industry Leader
Posts: 2382
Joined: Thu 21 Jun, 2007 21:27
Location: San Rafael, California

New to using a real test kit. (ColorQ Pro 7)

Postby chem geek » Wed 01 Jun, 2011 20:31

The appropriate Free Chlorine (FC) level for your pool depends on the Cyanuric Acid (CYA) level as shown in the Chlorine / CYA Chart . While you are there, you can read other areas of the Pool School as well.
Gator12

New to using a real test kit. (ColorQ Pro 7)

Postby Gator12 » Sat 11 Jun, 2011 23:59

Your Combined Chlorine (TC-FC) should be between 0.00 and 0.2ppm, yours is .85ppm. In order for you remedy this problem you need to figure out what your Breakpoint Chlorination is.
1. Calculate your CC (TC-FC)
2. Calculate Breakpoint Chlorination BPC= CC x 10. (.85ppm x 10 = 8.5)
3. Determine amount of change BPC – FC = (8.5 – 5.53 = 2.97ppm)

Now you can figure out how much of a given chemical to add to your pool to change it by that amount.

Amount of Chemical x Pool Volume x Desired Change = Total Amount to Add
2.0oz x 1.3 x 2.97 = 7.7oz of Cal Hypo

Amount of Chemical
-If you add 2oz of Cal hypo to a 10,000 gal pool it will raise the chlorine level by 1 ppm

Pool Volume
-Most pool chemicals that you add seem to be based on a 10,000 gal pool. Since yours is 13,000gal, 13,000/10,000= 1.3

Desired Change
-You determined that you need to change it by 2.97ppm/ 1ppm(the change amount for adding 2oz of cal hypo to the pool

Now I am not too familiar with Fiberglass pools, I would look into whether or not calcium hypochlorite is the best choice of chemical to shock your pool. You might be better using lithium hypochlorite which is 3.8oz for a 1ppm change.

As for an Ideal FC level, it really depends on where you live. In FL in the summer/ hot seasons, I test my pool once a week and keep it at 5ppm. The ideal range is 2 – 4ppm.
chem geek
Pool Industry Leader
Pool Industry Leader
Posts: 2382
Joined: Thu 21 Jun, 2007 21:27
Location: San Rafael, California

New to using a real test kit. (ColorQ Pro 7)

Postby chem geek » Wed 15 Jun, 2011 21:52

I'm assuming his ColorQ is giving him some bogus readings for TC-FC=CC. It's unlikely the CC is that high if this is an outdoor residential pool exposed to sunlight unless his CYA level is extremely high.

The 10x rule for breakpoint chlorination is wrong. It is based on the chlorine oxidation of ammonia which each measured in their own units of measurement does result in about 10x. It's 3 chlorine to 2 ammonia, but chlorine is measured in ppm Cl2 while ammonia is measured in ppm N which is a factor of 5 different so the ratio is 7.6 which with side reactions is 8-10 so people just simplified that to call it 10x. However, CC is not measured in ammonia ppm N units, but rather in ppm Cl2 units so there is no factor of 5. Also, one of the chlorine is already attached to ammonia in monochloramine. Anyway, shocking with chlorine will make oxidation of CC go faster, but I doubt there's real CC in this person's pool. I suggest using a real test kit that is known to be accurate such as the Taylor K-2006 or the TFTestkits TF-100 .

As for shocking the pool, why in the world would one ever use lithium hypochorite which is extraordinarily expensive when they can instead use chlorinating liquid or bleach?
Tommyt
Pool Newbie
Pool Newbie
Posts: 4
Joined: Wed 01 Jun, 2011 06:48
My Pool: 13,000 gallon - Fiberglass
Sand Filter/2HP pump
Stamped concrete deck with custom tile
3 inch chlorine for sanitizing

New to using a real test kit. (ColorQ Pro 7)

Postby Tommyt » Sun 19 Jun, 2011 10:15

I really appericate the help... Probably information overload, but I'm looking at all the details I can find to try to find a simple process to determine the action I need to take with the results I find...
Updated test:

Temp=79
CL=.84
TC=1.57
Ph=7.1
Aly=81
CH=103
CYA=119

Looking at the CYA chart, Its seems to be high. What I'm reading, I may need to replace about 30% of my water to lower my CYA. Did I miss something?
chem geek
Pool Industry Leader
Pool Industry Leader
Posts: 2382
Joined: Thu 21 Jun, 2007 21:27
Location: San Rafael, California

New to using a real test kit. (ColorQ Pro 7)

Postby chem geek » Sun 19 Jun, 2011 18:10

Assuming your CYA reading is accurate, then you are correct. Note that the ColorQ is known for the worst accuracy with the CYA test and for high CH levels. The other tests are usually OK.

So yes, dilute your water to get the CYA lower as that will make any chlorine you add more effective. Add more chlorine to get your FC up as prescribed earlier.
Tommyt
Pool Newbie
Pool Newbie
Posts: 4
Joined: Wed 01 Jun, 2011 06:48
My Pool: 13,000 gallon - Fiberglass
Sand Filter/2HP pump
Stamped concrete deck with custom tile
3 inch chlorine for sanitizing

New to using a real test kit. (ColorQ Pro 7)

Postby Tommyt » Sun 19 Jun, 2011 19:30

Thanks for the quick response... Already working on "add water" issue first and will retest. Also added some chlorine even thought I understand its not as effective right now.

May also get a "store" test done to validate my ColorQ 7 test.

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