chlorine levels barely budging

[danaz]

Returned a bucket of 3" pucks and other products to walmart yesterday and picked up 4 gallons of 10% liquid chlorine for $14 - it worked out cheaper than the 6% bleach.

Poured some in the pool last night to theoretically take me from 1ppm to 3ppm according to the pool calc and this morning it is looking clearer again. Hard to tell from the pics but the main drain at 10ft deep is a lot clearer than before. I will test and probably repeat again tonight depending on results and hopefully the test kit will arrive around thursday/friday.

 

[danaz]

Just done a test at lunch with basic HTH 2 test kit.
OTO test showed chlorine still between 1 and 2
Phenol PH test has dropped to 7.2

This is after pouring half a gallon of 10% chlorine into the pool last night. According the pool calc this should have increased chlorine from 1 to 3, but it's still hovering around 1 to 2, at least according to this test kit.

Interesting since i have never know the PH in this pool to drop below 7.6. Usually it tends to drift upwards and need lowering. Is this a side effect of using liquid chlorine last night for the first time?

Pool water is visibly looking much clearer though - it's definitely becoming more blue than green.

 

[jblizzle]

You may have raised FC from 1 to 3 last night, but if there are any organics they would have used some of it over night. If you want to check your dosing, add the chlorine in front of a return with the pump running and then test the FC level after 60 minutes (although if stuff is growing it will start depleting it pretty quickly).

Generally liquid chlorine does not have a long term affect on pH.

 

[danaz]

You may have raised FC from 1 to 3 last night, but if there are any organics they would have used some of it over night. If you want to check your dosing, add the chlorine in front of a return with the pump running and then test the FC level after 60 minutes (although if stuff is growing it will start depleting it pretty quickly).

Generally liquid chlorine does not have a long term affect on pH.

I also suspected that the cleaning of the pool had depleted the chlorine level, but was not 100% sure about it. After all, the pool is cleaner than before introducing the liquid chlorine so the water is certainly undergoing some kind of chemical process.

Curious about the PH dropping to 7.2 but if liquid chlorine does not effect PH then my next thought is suspect it might be the delayed effect of adding the PH minus a few days ago. Perhaps i added too much and by measuring it the day after i got a false reading due to the PH not yet being fully absorbed. 7.2 is not the end of the world tho.

 

[carlscan26]

pH changes should only take 1-2 hours to register if you have good circulation.

FYI - You will want to remove your cleaner and hoses before you begin shocking - high CL levels can damage the cleaner and hoses.

 

[danaz]

Hmm..well if pH changes occur that quickly then i'm at a loss at to why it went from 7.6 to 7.2 in 48hrs. Maybe human error on my part with the testing. I think the circulation is fine as the vacuum charges about and the return jets are nice and powerful. Something to keep an eye on when the test kit arrives.

Thanks for the advice on chlorine damaging the pool equipment when shocking.

 

[danaz]

Well got the test kit and here are the results

TA 110
CH 200
FC 2
CC 2
TC 5
CYA 110
PH 7.2

From the pool calc i think i need to remove about 40% of the water to reduce the CYA.

Now i have a TRITON II 140 filter and WhisperFLO pump and looking at the documentation i think both of these would pump out way more than the 12 gallons per minute recommended by the city for pumping water into the sewer clean-out.

I am guessing there is no way to inhibit the flow and i just have to rent a submersible pump for a couple of days to clear out 10,000 gallons of water?