High TA and CH levels.

[jschner]

I have an older 17,000 gal inground plaster pool in Arizona, lots of sun. I almost always use liquid chlorine.
Using a Taylor Kit
FC 2.6
CC 0.2
PH 7.4
TA 125
CH 700
CYA <30

Ph was 8.0 a few hours ago. Used Clorox ph Down. I think these levels are ok now, I will add a gallon of chlorine which would raise FC levels to about 7ppm. Also TA and CH are always high due to city water in Arizona. I think that is why my PH is always creeping up. I have started using 3" tablets again for a short period to help bring CYA up slowly.

One note, my MX8 crawler does not have a basket and feeds whatever it picks up straight to the DE filter. With so many sand storms, German Shepard always jumping in, and wind blowing green material in the pool I have to backwash my DE filter at least 6 times a year. This brings in more hard water from the city so I live with the high TA and CH levels and deal with the creeping PH and some tile scaling issues. Curious if I am on the right track here or suggestions?

 

[Rancho Cost-a-Lotta]

What's the CH of your fill water?

You should figure out a way to top off with softened water to slow down/eliminate CH rise. If you have a whole-home softener you could tap into that. There are smaller automated units that are relatively inexpensive you could use for the pool only, but you need power, a water source, and a sewer cleanout for the effluent. I use an portable RV softener. I get about 3-4 weeks of softened water out of mine before it needs manual flushing (link in my sig). With higher CH levels, more frequent flushing is required.

It may be better to disassemble and clean the filter as opposed to backwashing which requires more top-off water.

Tablets will help to control pH. Just keep "tabs" on your CYA level.

TFP recommends the use of muriatic acid as opposed to sodium bisulfate. Dry acid causes a build up of sulfates in the pool which can damage metals and plaster.

Monitor your CSI. Try to maintain a slightly negative value (0.0 to -0.30) to mitigate scale build up. When it be becomes unmanageable, you'll need to reduce calcium levels by doing a water exchange or reverse osmosis.

 

[jschner]

Fill water is straight from city, does not go through our water softener. No easy way to change that. Maybe I could occasionally hook up a few hoses from the softener to the pool, probably about 150-200ft.

CH of fill water varies but is around 600 right now. TDS is high right now at 1400. I don't drink our water, even when it goes through our softener.
Pool water is currently around 86-88F degrees. I will try figuring out CSI and watch that.

I did not know tablets might help with pH, I will definitely watch how the pH reacts to tablets, watch CYA and switch back to Muriatic acid. Many times I am dumping two gallons in to reach normal pH levels so this will be interesting to see if tablets help. Just don't want my CYA levels to creep too high though.

Things to try, thank you!

 

[Rancho Cost-a-Lotta]

I doubt your calcium level is that high. I would guess it's around 200 to 250. Did you perhaps use a 25 ml sample as opposed to a 10?

If it were my pool, I would find a way to plumb The Fill line to the softener. It will save you money in the future and is a worthwhile investment.

Best wishes!

 

[jschner]

I used 10ml because it is always really high. When I moved in 5 years ago, CYA was through the roof, around 180 and I backwashed regularly and switched to liquid chlorine to get that down. CH stayed the same TA fluctuates sometimes around 60-80 but usually around 100.

City fill water is horrendously hard and full of calcium. It is impossible to wash my beater vehicles with it and leaves them almost worse then before you washed them, regardless if you jump in and drive fast to dry the vehicle or wipe with a towel. I sure miss my Northern California water near the Oregon border.

I'll look into the small water softener for the pool as all those lines and power converge there.

 

[Rattus Suffocatus]

What's the CH of your fill water?

You should figure out a way to top off with softened water to slow down/eliminate CH rise. If you have a whole-home softener you could tap into that. There are smaller automated units that are relatively inexpensive you could use for the pool only, but you need power, a water source, and a sewer cleanout for the effluent. I use an portable RV softener. I get about 3-4 weeks of softened water out of mine before it needs manual flushing (link in my sig). With higher CH levels, more frequent flushing is required.

I'll have to do the math but it is possible that one of the smaller units could work for me, especially if I did something like recharging it bi-weekly. I assume you add the four boxes of table salt (in the camping world description) that to the unit by unscrewing the top to do the recharge? Can you use pool salt or water softener rock type salt or does it have to be fine?

I have to admit since I am not a RVer that I never thought of this. It certainly is intriguing and I probably ought to be doing it. I'll have to start working some math tonight up based on the water reports. I wonder if running a second pump through it from the pool water could also lower CH in the existing pool water. I might be missing something here, like other chemicals in the water like CYA being bad for the exchange resin. I probably have a suitable pump even, since it's water hose in and out....

 

[mknauss]

I assume you add the four boxes of table salt (in the camping world description) that to the unit by unscrewing the top to do the recharge? Can you use pool salt or water softener rock type salt or does it have to be fine?

yes, but use pool salt or pickling salt. No additives.

I wonder if running a second pump through it from the pool water could also lower CH in the existing pool water. I might be missing something here, like other chemicals in the water like CYA being bad for the exchange resin.

Chlorine will destroy the resin beads, so no go on putting the pool water through it.

 

[Rattus Suffocatus]

Gotcha. Makes sense. Ultimately, even here in the desert, doing a partial water exchange doesn't cost that much in reality. I don't know if I want to go back to the solar cover, except maybe in the winter as a winter cover, and in the spring as a solar heater... and that is enough to push me into having to think about this issue and probably act. It made the CH creep a LOT less, believe it or not, but it also made the rest of the family not use the pool

I have a weekend place (it's a fully redone double wide) down near Sierra Vista, AZ (currently plan on retiring there in 5-7 years, selling the pool for good but likely keeping a standalone hot tub) that has a loop and previously had a rented outdoor softener .. I might consider the RV type there too 9 months a year as I don't like how they did the outside enclosure for the softener... that could be a temporary solution for a couple of years until I add a small heated shed on end the place to replace the poorly insulated "box" they used.. It's 1200' higher than my place in the outskirts of Tucson and probably 2200' higher than the airport, so it DOES freeze at night in the winter and rarely during the day there even though it's 40 miles further south (whoo hoo! 100 MPH high speed border chases every day! The struggle is real!). It also rarely breaks 100F there. But.... I have to cut the grass there this weekend... a few times a year.... that I didn't miss from the Midwest with the Xeriscaping in Tucson...