Options for reducing calcium hardness

[Pierrot]

Hi,

Where I live, it hasn't rained in 4 months, and the tap water is pretty hard. So everytime I refill the pool to compensate for evaporation, I'm adding calcium. Calcium hardness just reached 1000ppm in my pool. At that level, it becomes difficult to keep the CSI in check.

Partial drain and refill is the recommended option from what I can read. But again, I live in a pretty dry area, and water is expensive (I also, I just don't like the idea of wasting water at all).

Two options I'm considering:

• I've seen flocculant for calcium? Do they work? I assume using them means cleaning the cartridge filter afterward but I don't mind. They are due for a cleaning anyway.
• Buying a sump pump and a portable water softener and treat my water this way. Has anybody done that? Is that stupid? Would this method impact other chemical levels?

Thanks!

 

[PoolStored]

I've seen flocculant for calcium? Do they work? I assume using them means cleaning the cartridge filter afterward but I don't mind. They are due for a cleaning anyway.

No. Calcium hardness can be removed by replacing the high CH water with lower CH water or by using Reverse Osmosis. That is it.
Some folks in high CH areas use softened water as make up water after the pool is filled. That way they do not build CH in the water. If you use high CH water to fill the pool due to evaporation, your CH rises.

Buying a sump pump and a portable water softener and treat my water this way. Has anybody done that? Is that stupid? Would this method impact other chemical levels?

The sump to remove water is spot on. You should not 'drain'...see "no drain water exchange" in the article below. You would need to have a more permanent water softener, and understand the generation cycle to know how much with each exchange. Yes, it will lower/alter other water parameters. What is the TA and CH of your fill water?

Draining - Further Reading

www.troublefreepool.com

 

[Pierrot]

The sump to remove water is spot on. You should not 'drain'...see "no drain water exchange" in the article below. You would need to have a more permanent water softener, and understand the generation cycle to know how much with each exchange. Yes, it will lower/alter other water parameters. What is the TA and CH of your fill water?

Fill water TA is 140ppm, CH is 220ppm.

To be clear, my idea wasn't to replace the water as explained in the "no drain exchange" in the article you linked. It was to: pump the water from the pool using the sump pump, have it go through a water softener, and then back into the pool.

If I do that, what other parameters besides CH will be changed in the treated water?

 

[Rancho Cost-a-Lotta]

The higher chlorine levels used in pool water will damage the resin beads in a softener.

Have you checked your water billing calculated the amount it would cost to drain and refill the required amount of your pool volume? It's likely much less than you think. Once you get your CH level down to an acceptable range, use softened water to top off.

 

[Pierrot]

The higher chlorine levels used in pool water will damage the resin beads in a softener.

Good point, I hadn't thought of that.

Have you checked your water billing calculated the amount it would cost to drain and refill the required amount of your pool volume? It's likely much less than you think. Once you get your CH level down to an acceptable range, use softened water to top off.

18k gallons pool. Rates here are $8 per 768 gallons.

If I were to half drain and refill, that would cost 18000/2/768 * 8 ~= $100. This would bring my CH to 500ppm. I'd probably do it one more time to bring it down to 250ppm. So about $200. Not the end of the world indeed, but again wasting so much water makes me uncomfortable.

 

[PoolStored]

If I were to half drain and refill, that would cost 18000/2/768 * 8 ~= $100. This would bring my CH to 500ppm. I'd probably do it one more time to bring it down to 250ppm. So about $200. Not the end of the world indeed, but again wasting so much water makes me uncomfortable.

I would use the no drain water exchange and do it in one fell swoop. If you drain/add, drain/add, it will mix between and you will not reduce as much as you expect.

 

[mknauss]

In San Diego, I would drain and refill, completely. Then find a way to use softened water for fill water.

 

[Rancho Cost-a-Lotta]

Those are some high water rates...all the more reason to invest in connecting the fill line to a water softener.

 

[mas985]

Good point, I hadn't thought of that.


18k gallons pool. Rates here are $8 per 768 gallons.

If I were to half drain and refill, that would cost 18000/2/768 * 8 ~= $100. This would bring my CH to 500ppm. I'd probably do it one more time to bring it down to 250ppm. So about $200. Not the end of the world indeed, but again wasting so much water makes me uncomfortable.

Have you considered RO?

Pool Reverse Osmosis from Williams Water Purificaiton

Dont drain your pool! Our reverse osmosis process eliminates the need to drain and refill your pool, which can be costly and time-consuming.

www.williamswaterco.com

It will cost more than a refill and there is some waste (15%-20%).

 

[Pierrot]

In San Diego, I would drain and refill, completely. Then find a way to use softened water for fill water.

Any recommendation for a softener? I'll probably install one for the fill water only, not a whole house one.

Have you considered RO?

No not yet, my understanding is that RO removes everything (like CYA) and not just Calcium. But I'll look into it. Thanks for the link.

 

[proavia]

A whole house water softener would save additional money in soap, washer/dishwasher maintenance and plumbing fixrures from not having the calcium present there either. And will lessen dry skin as well.

If you can pull is off, a whole house system would be best. You can also add a RV type water softener near the autodill supply line - but these need to be monitored and regenerated manually when needed. Also, RV sized water softeners are smller with less capacity to soften water.

 

[mknauss]

Any recommendation for a softener? I'll probably install one for the fill water only, not a whole house one.

If you have an option to install a small whole house one, do it. I could not as I did not have a place for my effluent (backwash) to go. It is high salinity water so you need to have a drain to your sewer or an area for a deep well drain that has no plants around it.
Otherwise, you can use an RV softener. More work, as you must manually backwash it. I have a Double size version and have to backwash every 700 gallons of water run through it. Your CH is similar to mine (Colorado River water).

 

[Pierrot]

If you have an option to install a small whole house one, do it. I could not as I did not have a place for my effluent (backwash) to go. It is high salinity water so you need to have a drain to your sewer or an area for a deep well drain that has no plants around it.
Otherwise, you can use an RV softener. More work, as you must manually backwash it. I have a Double size version and have to backwash every 700 gallons of water run through it. Your CH is similar to mine (Colorado River water).

Yes an RV one will likely be too small. During summer I have around 130 gallons evaporating everyday, so I'd have to backwash it manually every 5 days or so. Too much work

 

[mknauss]

Yes an RV one will likely be too small. During summer I have around 130 gallons evaporating everyday, so I'd have to backwash it manually every 5 days or so. Too much work

They make bigger ones. But I would strongly suggest a 30K grain water softener if at all possible, if just for the pool.
Your water is about 16 gpg. So you can run 1500 gallons or so before backflush. It will use about 20 gallons of water to backflush.