I am looking for a little advice on the balance of my chemicals…more so the chlorine. I have about a 20,000 gallon in ground pool and use an Inline Hayward chlorinator (right size for the pool and I keep it full). The pump runs about 8 hours every night. Currently my total alkalinity is between 80-100, the ph was a little low 6.8 yesterday but should be back up to 7.2 as of this morning (because I put increaser in last night). The water looks crystal clear…but I started noticing some black staining sporadically appearing on the vinyl liner throughout the pool yesterday… more so in the deep end. I vacuumed the normal stuff off the bottom, but even with a brush the stains would not come off.
That’s when I tested the chlorine level. The kit I use is not the strips, it is called ‘pool trouble shooter’ and it only allows me to test the chorine, Ph, and alkalinity, and involves putting the drops in the little color coded container etc. My chlorine level was 0 when I checked this.
The thing that is confusing me is that my Chlorinator is using up the pucks…actually in what appears to be a pretty fast pace. So I know the chlorine is going into the pool, but I don’t get why it is not showing up on the test... and why I started to get the black stains. After putting in the liquid shock yesterday eve the stains from the bottom are gone this morning. I checked the chlorine levels with the test kit after putting in the shock, just out of curiosity (to rule out whether the test chemicals have gone bad over the winter) but sure enough it turned pink.
So my question is…why is the chlorine from the pucks not registering on the test kit. I keep the chlorinator at about a setting of 4, and like I said it’s flying through the pucks (I keep it full) so I know it’s going into the pool. The water is crystal clear but I started getting that dark staining...which disappeared with liquid shock. I know little about stabilizer… but the pucks I use are supposed to be stabilizing pucks (big tub from Costco).
Thanks in Advance for your help!