Henry_R wrote::problem:
Once again the chlorine is near zero. I dumped what should have been enough to bring it up to 10ppm last night; two and a half gallons according to the poolcalculator. Either that 10% liquid shock was old
and ineffective or something else is wrong with the water chemistry. There are date codes on the liquid shock bottles. How do I read the codes? The bottles were dirty. Perhaps they were old stock. Is it not true that chlorine degrades in the bottle over time?
How long after adding liquid chlorine should I be able to get a good reading?
The test kit is a DPD type not OTO and I'm wondering if that the problem.
The OTO kit I returned since it was missing it's CYA testing tube(dot tube), but it showed
chlorine at least at 5 or more. The DPD test show no color at all. Even last night after I added all that chlorine there was no reading. Shoudn't there have been some reading?
The pH seems to have stabilized at 7.5 and it's staying put for now.
The water is still murky and still has a seafoam greenish look, at least to my eyes.
The filter pressure has bugged up to 15psi from 12.5psi it was staying at before.
I'm not entirely sure that gauge is accurate either due to it's age.
It's quite possible that the chlorine level is quite high and it's bleaching your test so showing clear. Chlorine does lose strength over time so it may have been weaker than expected.
The filter pressure going up is what you would expect as it cleans the water.
I forget if you have vacuum gear. Have you been able to vacuum the pool? Much debris in there?