Recommendations to remove hardness in salt water pool

[aerobatix]

I live in Southern California, and my Calcium levels are up to 550 in my 15k gal salt water pool. I've been having problems with calcium flaking off my SWG, and scale around the tiles at water level. I have a couple of options:
1. Drain totally and fill with tap water (~30 ppm Ca here, but high in carbonates)
2. Partially draining, and refilling with tap water to bring the Ca down to ~200 ppm
3. Same as #2 but refilling with softened (ion exchange) water
4. Using one of these services that brings a truck by to "restore" the water by pumping it back through RO membranes.

#1 is very expensive where I live because we are in a partial drought and water is expensive.
#2 would be a cheaper way to go, but would I just be punting the problem for a year or two?
#3 seems the most attractive to me, as I have a whole-house RO system, and salt is cheap. I've read concerns in these forums about high sodium levels with ion-exchange water, but do I need to be concerned with a salt water pool?
#4 seems like snake oil, but I know it is popular around here. Apparently the pump trailer stays in your driveway for 24-48 hrs., and the service runs about $1K for a pool my size.

All suggestion welcome, and thanks in advance.

 

[YippeeSkippy]

Hello! WELCOME to Trouble Free Pool.
How do you test your water? We advocate for owners having a GOOD test kit (either the K-2006C or the TF-100 or Pro from www.tftestkits.net) We need your current values for these tests:
FC
CC
pH
TA
CH
CYA
Salt if applicable

Many, many TFP folks who live out west deal with calcium levels far higher than yours. One way to manage this is by keeping the pH on the low side (7.2 ish) and of course having the TA (Total Alkalinity) also on the lower normal end so that it won't constantly work to "pull up" the pH. High pH contributes to your scaling problem.

Some tips:
Pool Care Basics
PoolMath
www.troublefreepool.com/wiki/index.php?title=Calcium_Hardness
www.troublefreepool.com/wiki/index.php?title=Draining

If I was in your situation I would do a partial drain and fill with lower hardness tap water, then use softened water when you need to top off occasionally. Pool Math can advise you on how much to drain to meet your goals.

If you have more questions, just holler!

Maddie

 

[nobody291]

I've read concerns in these forums about high sodium levels with ion-exchange water, but do I need to be concerned with a salt water pool?

The water softener adds some sodium to the water, but doesn't add salt. The salt is used by the softener in the process of maintaining itself. The salty water from that maintenance process gets flushed through a separate drain periodically, and only the sodium remains to use in the ion exchange for the water provided to your house. There are others here that can go into way more detail on this process if you're interested. I use softened water to fill my pool and it is great. If you look back through my logs, you'll see that my CH rarely changes during normal times. I actually had to add calcium recently to bring my pool back up above the 250ppm recommended minimum for a plaster pool after our crazy socal rainy winter.

In addition to Maddie's suggestions above, add details about your pool to your signature so we can better help you with questions (for this question, it's important whether you have a plaster pool).

 

[aerobatix]

Hello! WELCOME to Trouble Free Pool.
How do you test your water? We advocate for owners having a GOOD test kit (either the K-2006C or the TF-100 or Pro from www.tftestkits.net) We need your current values for these tests:
FC
CC
pH
TA
CH
CYA
Salt if applicable

Many, many TFP folks who live out west deal with calcium levels far higher than yours. One way to manage this is by keeping the pH on the low side (7.2 ish) and of course having the TA (Total Alkalinity) also on the lower normal end so that it won't constantly work to "pull up" the pH. High pH contributes to your scaling problem.

Some tips:
Pool Care Basics
PoolMath
www.troublefreepool.com/wiki/index.php?title=Calcium_Hardness
www.troublefreepool.com/wiki/index.php?title=Draining

If I was in your situation I would do a partial drain and fill with lower hardness tap water, then use softened water when you need to top off occasionally. Pool Math can advise you on how much to drain to meet your goals.

If you have more questions, just holler!

Maddie

Thanks for the reply. I use a K-2006 kit. FC=5.0 CC=0 PH=7.4 TA=86 CH=554 CYA=30 NaCl=2700
SWG is currently INOP. Water is clear, but I have some brown spots on bottom of pool that disappeared when I shocked, but came back. These spots get worse when pool cover is on (12+ hrs) and better when open in sunlight. Brushing does not help. Going to try SLAM again before replacing SWG.

 

[Rancho Cost-a-Lotta]

Your test results for TA, CH and Salt are not valid results for the K-2006 test kit. Not sure where you got those results, but if they're from the pool store, don't trust them.

You likely lost 35%-45% of your pool volume to rains this season so your CH may not be as high as the results suggest. You fill water is likely higher than 30 ppm.

 

[mknauss]

Welcome to the forum.

Your first post said your fill water CH was 30. That is not likely possible with the source of your fill water.

 

[aerobatix]

The water softener adds some sodium to the water, but doesn't add salt. The salt is used by the softener in the process of maintaining itself. The salty water from that maintenance process gets flushed through a separate drain periodically, and only the sodium remains to use in the ion exchange for the water provided to your house. There are others here that can go into way more detail on this process if you're interested. I use softened water to fill my pool and it is great. If you look back through my logs, you'll see that my CH rarely changes during normal times. I actually had to add calcium recently to bring my pool back up above the 250ppm recommended minimum for a plaster pool after our crazy socal rainy winter.

In addition to Maddie's suggestions above, add details about your pool to your signature so we can better help you with questions (for this question, it's important whether you have a plaster pool).

Thanks, added info to my signature. My tap water is very high in carbonates, So I am concerned about ion exchange water bumping up my alkalinity

Welcome to the forum.

Your first post said your fill water CH was 30. That is not likely possible with the source of your fill water.

I think I said 30 Ca not CH. My recent sample showed 28 Ca, 72 Na, 50 sulfate, 60 chloride and 150 bicarbonate. It comes from the Los Angeles aqueduct treatment plant, and based on the numbers, they are probably using sodium bicarbonate to soften the water supply.

 

[nobody291]

So I am concerned about ion exchange water bumping up my alkalinity

In case you haven't done this already. it's worth testing the fill water that you use with your K-2006 to see what you're adding. I tested both my softened and un-softened water:

Un-softened: TA=110, CH=150, pH=7.6
Softened: TA=110, CH=25, pH=7.8

So, in my case, the TA isn't (measurably) different.

 

[mknauss]

Thanks, added info to my signature. My tap water is very high in carbonates, So I am concerned about ion exchange water bumping up my alkalinity

I think I said 30 Ca not CH. My recent sample showed 28 Ca, 72 Na, 50 sulfate, 60 chloride and 150 bicarbonate. It comes from the Los Angeles aqueduct treatment plant, and based on the numbers, they are probably using sodium bicarbonate to soften the water supply.

You are right. But none of those items matter to pool water chemistry. Test your fill water for what matters.

 

[reggiehammond]

Where is the CH coming from? Your fill water? The "shock" you mentioned you're using which is cal-hypo (almost half the bag is calcium)?

I recommend visiting pool school (over on left) and read up more on the TFP method. I am going to assume the calcium source is "shock" which is absolutely unnecessary. If so - I'd do a partial exchange, and start following the TFP methods. The CH will not return.

 

[PoolStored]

I think I said 30 Ca not CH. My recent sample showed 28 Ca, 72 Na, 50 sulfate, 60 chloride and 150 bicarbonate.

I'm getting lost in the acronyms. We use these here at tFP, and they are the same as the test results from your K-2006.
pH = pH
FC = Free Chlorine (the fas/dpd test)
CC = Combined Chlorine (second part of the fas/dpd test)
CYA = Cyanuric Acid
CH = Calcium Hardness
TA = Total Alkalinity

I'm not sure what your acronyms are, or where you got them.