Over the weekend we got around to doing the first drain of our new hot tub. I've been running the thing with the Frog @Ease cartridges that it came with since July with what seemed like decent results. Water was clear and only occasionally foamy if I let the pH or TA wander too much.
Prior to draining, we did an AHH-some purge for 45 minutes with the filters pulled out and floating and all the air valves open. Plenty of green goop showed up, and we wiped it up and then dumped the water. Wiped down the shell and refilled. I used a filter on the hose like the first time. I was excited to fire up the SmarterSpa, so I put in half a box of borax (enough to bring it to 80ppm) , and 12 cups of pool salt and put the cell in before it was even all the way full. The salt level read okay and it started making bubbles. Hooray!
Once the spa was full, I did check the levels of everything and adjusted the CH and pH which was way high from the borax. Didn't occur to me that the calcium chloride I added for the CH is also salt, so now the cell is saying the salt concentration is high, but still working. Not worried about that too much. I can dump some water and add fresh if I need to. I also did a start up shock with 1 oz dichlor to add some CYA and get the FC up quick. That took the FC up to 6ish.
This is where it gets weird. I left the spa to warm up over night, going from 60 degrees out of the hose to the 80 degree setpoint. When I left it for the night, it was reading 3.6ppm FC. The next morning the SmarterSpa was on, generating, I don't know for how long. I tested the water and the FC was 0.4 ppm but everything else was pretty good. I shut off the SWCG and added another half an ounce of dichlor to help the SWCG catch up and to get even more CYA into the water, should be around 10ppm now.
That brought the FC to 2.6ppm. That time I checked the CCs too and they were at 4.0ppm. I then turned up the water temp to 100 hoping to use it tonight.
Left it for most of the day. Noticed that the SmarterSpa again turned on fairly early in the day. I don't know the precise setpoint yet, but I had bumped it up a bit from the factory default, since 0.4ppm is too low for my taste. I checked the FC after it was running for all day, about its whole 7 hour cycle, I checked the chlorine again and it was 1.8 FC, meaning that it had dropped from 2.6 far enough to trigger the cell and the cell had spent hours pumping it back up to 1.8 ppm. CC was 3.6ppm.
This seems like a lot of chlorine demand for an empty spa with the top on.
One more item, after we refilled the water, we noticed we were getting weird deposits around the waterline, different from what had shown up with the Ahh-some purge. Like black or reddish flecks, almost like pepper. That seems to be clearing up, but it makes me think we didn't get everything with the purge.
What steps should I take now?
I'm probably going to hit it hard with another big shot of dichlor to bring the CYA to 20 and kill whatever is still in there hopefully, but if this is still being dodgy by next weekend I'll purge and dump again. I just hope the weather holds, November is getting pretty late to be messing around with the hose.
Prior to draining, we did an AHH-some purge for 45 minutes with the filters pulled out and floating and all the air valves open. Plenty of green goop showed up, and we wiped it up and then dumped the water. Wiped down the shell and refilled. I used a filter on the hose like the first time. I was excited to fire up the SmarterSpa, so I put in half a box of borax (enough to bring it to 80ppm) , and 12 cups of pool salt and put the cell in before it was even all the way full. The salt level read okay and it started making bubbles. Hooray!
Once the spa was full, I did check the levels of everything and adjusted the CH and pH which was way high from the borax. Didn't occur to me that the calcium chloride I added for the CH is also salt, so now the cell is saying the salt concentration is high, but still working. Not worried about that too much. I can dump some water and add fresh if I need to. I also did a start up shock with 1 oz dichlor to add some CYA and get the FC up quick. That took the FC up to 6ish.
This is where it gets weird. I left the spa to warm up over night, going from 60 degrees out of the hose to the 80 degree setpoint. When I left it for the night, it was reading 3.6ppm FC. The next morning the SmarterSpa was on, generating, I don't know for how long. I tested the water and the FC was 0.4 ppm but everything else was pretty good. I shut off the SWCG and added another half an ounce of dichlor to help the SWCG catch up and to get even more CYA into the water, should be around 10ppm now.
That brought the FC to 2.6ppm. That time I checked the CCs too and they were at 4.0ppm. I then turned up the water temp to 100 hoping to use it tonight.
Left it for most of the day. Noticed that the SmarterSpa again turned on fairly early in the day. I don't know the precise setpoint yet, but I had bumped it up a bit from the factory default, since 0.4ppm is too low for my taste. I checked the FC after it was running for all day, about its whole 7 hour cycle, I checked the chlorine again and it was 1.8 FC, meaning that it had dropped from 2.6 far enough to trigger the cell and the cell had spent hours pumping it back up to 1.8 ppm. CC was 3.6ppm.
This seems like a lot of chlorine demand for an empty spa with the top on.
One more item, after we refilled the water, we noticed we were getting weird deposits around the waterline, different from what had shown up with the Ahh-some purge. Like black or reddish flecks, almost like pepper. That seems to be clearing up, but it makes me think we didn't get everything with the purge.
What steps should I take now?
I'm probably going to hit it hard with another big shot of dichlor to bring the CYA to 20 and kill whatever is still in there hopefully, but if this is still being dodgy by next weekend I'll purge and dump again. I just hope the weather holds, November is getting pretty late to be messing around with the hose.