Low chlorine reading

[PoolDoc]

Did your chlorine also drop? When chlorine is used up, the end product is acidic.

[sabres07]

Yes, I dumped in 7 gallons of bleach at 8 PM and tested the water shortly after. I finally had a high chlorine reading. At 11 PM I retested and the chlorine was at 0 and ph was at 7.8 or so. This morning I tested the water, and chlorine was still 0 but ph had dropped to 7.2.

My plan is to put 7 more gallons in tonight at 7 PM, and then re-test at 11 PM to see if it held or not. If it dropped again, I will reapply 7 more gallons of bleach. I am trying to break this ammonia or bacterial trap I am in. I was just wondering about this ph drop I had and how I should handle it in the middle of this trap I am in.

At 7:30 PM I added 6 gallons of bleach, chlorine readings were very high. I have retested every half hour since then and the chlorine seems to be holding. The ph however is dropping. It is at 6.8 now at 9:45 PM. Should I address this or should I just stay the course and keep the pool in shock mode?

[PoolDoc]

If you have some borax, I'd go ahead and add a box. It's not a crisis, but you don't want to leave the pH below 7.0 indefinitely.

[sabres07]

So after testing the pool at 11:30 PM last night, I was showing a reading above 5 ppm (as high as my test allows) but it was not as yellow as when 6 gallons of bleach was added at 7:30 PM. I added another 6 gallons of bleach. At 6 AM this morning, I tested and re-added 6 more gallons of bleach. Ph seems to be spiking when chlorine is added, as expected, and settles in at 7.2 hours later. Water is still cloudy, though.

I think I have turned the corner in my battle with whatever is causing my chlorine demand. Now I need a test kit that reads higher than 5 ppm chlorine. Does the 6 way HTH kit from Walmart read that high? I can get one today, otherwise I will order one from Amazon.

[Watermom]

The 6-Way kit does not read higher than 5. Only a FAS-DPD test can. That is why we encourage people to buy the Taylor K-2006 or 2006C kit.

[sabres07]

OK, I will get that test kit ASAP. In the meantime, based on amounts of bleach I have used, my chlorine levels should be 15-20 at the least, which is where I want to be for now, right?

[PoolDoc]

Just one emendation: the 6-way does not READ higher than 5 ppm, but it does INDICATE higher levels, by a transition from dark yellow (~10 ppm) to orange (~30 ppm) to brown (> 60 ppm).

This is a VERY important difference from the DPD color match tests, which can bleach out and read 0.0 at FC levels as low as 15 ppm! Before we began pushing OTO *or* DPD-FAS kits, we used to have lots of problems with people adding more and more chlorine to their pool, think they had none, when in fact it was way too high.