Hi TFP,
I just bought a home in Santa Barbara which came with an outdoor above-ground 235 gallon hot tub made out of roto-molded polyethelene. This is my first time owning a spa so I'm trying to get up to speed on pool chemistry and maintenance.
The tub was well maintained by the previous owner (using Dichlor granules), but was not balanced for several weeks while the house sat empty before we moved in. The house was also tented for termites before we moved in, which killed some plants near the spa and a big handful of dead leaves fell into the spa the first few times I opened the cover.
The water in Santa Barbara is quite hard- my test strip shows 250ppm CH in both the spa and the water supply. Test strips also show CYA in the spa is 150ppm from all the dichlor use. TA is on the high side but I was able to bring it down to ~100ppm with dry acid. Aerating usually brings the pH up to around 7.4, and the local spa shop told me not to worry about pH because it's "such a small body of water". (I understand that strips are not ideal but that's all I have right now; a Taylor K-2006 is arriving in a few days).
Now I've been trying to sanitize the spa for the last few days and having a really hard time keeping any FC. Yesterday I drained and refilled half the water to reduce CYA (now reads 150ppm). Overnight the water heated back up to 104F, and today I have added over 70oz of Bleach and still have no residual FC. CC started to rise initially but I think I reached breakpoint because TC matches FC now. I shocked with 3 cups of bleach this afternoon and read FC off the scale on my strips, but it was back down to zero a few hours later.
My plan now is to Ahhsome purge tomorrow and then drain/refill to start over without all the CYA. (But I'm not sure yet if I should fill with the 250ppm CH water or use softened water from inside our house.)
I'm guessing the purge and stabilizer reset will fix a lot of my problems, but I would like to know what is happening for future reference. If I understand correctly, the water has high chlorine demand from the dead leaves, and growth while FC was zero for extended period of time? (I read some things about "chlorine lock" due to high CYA as well, but it was unclear if that is a real thing). Theoretically If I kept dumping bleach into the water, would it eventually quench the demand and start retaining FC for more than a few hours?
I just bought a home in Santa Barbara which came with an outdoor above-ground 235 gallon hot tub made out of roto-molded polyethelene. This is my first time owning a spa so I'm trying to get up to speed on pool chemistry and maintenance.
The tub was well maintained by the previous owner (using Dichlor granules), but was not balanced for several weeks while the house sat empty before we moved in. The house was also tented for termites before we moved in, which killed some plants near the spa and a big handful of dead leaves fell into the spa the first few times I opened the cover.
The water in Santa Barbara is quite hard- my test strip shows 250ppm CH in both the spa and the water supply. Test strips also show CYA in the spa is 150ppm from all the dichlor use. TA is on the high side but I was able to bring it down to ~100ppm with dry acid. Aerating usually brings the pH up to around 7.4, and the local spa shop told me not to worry about pH because it's "such a small body of water". (I understand that strips are not ideal but that's all I have right now; a Taylor K-2006 is arriving in a few days).
Now I've been trying to sanitize the spa for the last few days and having a really hard time keeping any FC. Yesterday I drained and refilled half the water to reduce CYA (now reads 150ppm). Overnight the water heated back up to 104F, and today I have added over 70oz of Bleach and still have no residual FC. CC started to rise initially but I think I reached breakpoint because TC matches FC now. I shocked with 3 cups of bleach this afternoon and read FC off the scale on my strips, but it was back down to zero a few hours later.
My plan now is to Ahhsome purge tomorrow and then drain/refill to start over without all the CYA. (But I'm not sure yet if I should fill with the 250ppm CH water or use softened water from inside our house.)
I'm guessing the purge and stabilizer reset will fix a lot of my problems, but I would like to know what is happening for future reference. If I understand correctly, the water has high chlorine demand from the dead leaves, and growth while FC was zero for extended period of time? (I read some things about "chlorine lock" due to high CYA as well, but it was unclear if that is a real thing). Theoretically If I kept dumping bleach into the water, would it eventually quench the demand and start retaining FC for more than a few hours?
