High acid demand and salt question

[DeliciousBass]

Hi all, new pool owner, just over 2 months in managing my water (filled on 3/7) and with some help on a previous thread, I've gotten my numbers where I want them with a few exceptions/questions. My pb had my pool mode set to run the vs pump wide open (3300rpm) which had the spa spillover and the bubblers (our only two water features) running for 11 hours a day. With some help in previous thread, I was able to set my pool mode down to 1600rpm (stops the spillover), and I configured some other speeds on difference circuits, and now run 9 hours a day, where 7 hours are at 1650 and 2 hours are at 2700 to circulate water through the spa.

I can get my pH down to 7.0 and within 2 days it was running 7.8 - 8.0. After reducing the pump speed and run time, I can hold in the 7's for maybe 3 days, but I am basically adding 1-2 gallons of acid every week to week and a half to stay in the mid 7's. I've been reading other posts about pH/rain/aeration/new plaster, etc and am wondering if this is to be expected with plaster only being 2 months old? Also read that aeration can cause the pH to spike, so I found the valve that controls the bubblers and have them off for now to test. I turned them off yesterday with a pH of 7.2 and today pH is 7.6. Would like to eventually have an actuator installed on the valve for the bubblers, but that is above my pay grade atm. My current numbers are:
FC - 5.5
CC - 0
pH - 7.6
CH - 210 (going to work on bringing this up to around 250 this week)
CYA - 70
TA - 70

My other question is around salt. Until yesterday, I've been relying on the IC40 to tell me salt content, but my taylor kit arrived yesterday. In the 2 months I've been managing the pool, I've added at least 4, 40lb bags (possibly 6, but not positive) of salt to stay in the 3000's and closer to 3600, according to the IC40. Yesterday, I tested with the taylor kit and read 3600, today reads 3400, all while the IC40 on the app is telling me 2900. We had 14" of rain in April (avg is 10") and have already had 10.5" this month, 6" of that in last 3 days and have already beaten the May avg. Plus, kids have been using the pool since early April, so assume splash out as well. Is it normal to have that wide of a range between IC40 and taylor test? IC40 is scheduled for first cleaning 6/1, but has only been running since middle of March. With the test kit, I can keep a better eye on the salt level, but if it gets to 2800 on the IC40, the low salt light will come on.

Thanks !
Chad

 

[pjt]

You might be able to run your pump at an even lower RPM. See what it takes to close the flow switch of your SWG and provide adequate skimming, then add a little bit.

For salt readings, my K-1766 shows 3,600 but my IC60 indicates 2,900. It's common to have a difference between the two readings.

 

[ajw22]

Leave your bubblers off.

Your plaster is still curing and may be curing for a year or more. So get used to adding acid every 3 to 4 days.

Salt tests can be +/- 500 ppm. Add enough salt to keep the IC40 happy and don't exceed 3800 ppm as tested on the K-1766. As long as you stay in that range and keep the IC40 happy you are good.

Do NOT clean your cell with acid unless it absolutely needs it. Everytime you clean the cell with acid you remove some of the rare earths from the plates and decrease the cell life. Just look at the cell plates and if you se any scale use a strong stream of water to remove it or pick it off with a Popsicle stick.

 

[Jimrahbe]

Chad,

The IC40 has a tolerance of +/- 500 or 600 ppm.. I NEVER rely on what my cell says the salt level is... I do try to keep the cell happy, so that it produces chlorine, but I never try to keep what the cell reports at 3500.. As long as the cell is happy and I can keep the actual salt level (K-1766) below 3600 then that is what I do..

If the cell reports low salt, with the actual at 3500 or so, then I replace the flow switch. The flow switch assembly has a thermistor which measures water temp and the cell uses this info to determine salinity.. They go bad about once every 30 seconds..

Thanks,

Jim R.

 

[DeliciousBass]

Leave your bubblers off.

Your plaster is still curing and may be curing for a year or more. So get used to adding acid every 3 to 4 days.

Salt tests can be +/- 500 ppm. Add enough salt to keep the IC40 happy and don't exceed 3800 ppm as tested on the K-1766. As long as you stay in that range and keep the IC40 happy you are good.

Do NOT clean your cell with acid unless it absolutely needs it. Everytime you clean the cell with acid you remove some of the rare earths from the plates and decrease the cell life. Just look at the cell plates and if you se any scale use a strong stream of water to remove it or pick it off with a Popsicle stick.

Thanks, just wanted to make sure that was expected, so will continue to monitor and add. Good to know about cleaning, pb recommended cleaning every 3 months, so I was going to look into this on 6/1. I'm sure there are some good threads on here showing how to open it up, so will give it a shot and only use water. As for the bubblers, I have them off, but assume it is ok to run them on weekends if we have people over to swim, or if my wife and I want to have them on while we use the pool on occasion? Kids don't care, lol.

 

[DeliciousBass]

If the cell reports low salt, with the actual at 3500 or so, then I replace the flow switch. The flow switch assembly has a thermistor which measures water temp and the cell uses this info to determine salinity.. They go bad about once every 30 seconds..

Good to know, hoping this does not happen since it is less than 3 months old. Now that I have the K-1766, I can keep a better eye on the actual level and see when the IC40 reports low salt in comparison to what I actually have. Water temp has been between 76-80, with a couple days up to 84.

 

[ajw22]

pb recommended cleaning every 3 months, so I was going to look into this on 6/1. I'm sure there are some good threads on here showing how to open it up, so will give it a shot and only use water.

I would ignore the PB and check your cell maybe once or twice a year. The less you fool with it the less likely you will create a maintenance induced failure. If you follow TFP Recommended Levels the cell should never need cleaning.

To open it up you just turn off your pump and unscrew the two unions that hold it on the pipe.

As for the bubblers, I have them off, but assume it is ok to run them on weekends if we have people over to swim, or if my wife and I want to have them on while we use the pool on occasion? Kids don't care, lol.

Yeah, run your bubblers when someone is out there enjoying it. Turn it off when no one is around.