Idea to reduce calcium hardness

Jump to latest Follow Reply
J

JDC

0
Jan 8, 2015
6
Carlsbad, CA
Hi All,

I recently let my pool guy go and I'm in the process of balancing the water. First I found that the TA is low (40ppm) so I'm addressing that by adding baking soda. Our pool has always needed to add MA to combat high PH, and I think I just discovered why...

Next I noticed that I had absolutely no CYA as we have a SWC and our pool guy obviously didn't think we needed it. I am addressing that by adding CYA.

I'm now in the process of trying to figure out how to reduce my CH which is at 800.

I know the foolproof method is to drain the pool, and refill with new H20. I tested my tap water and the CH is at 350. So my plan would be to purchase a hose filter to reduce calcium, metals, etc.

Here's my idea - I have a spigot on my pool equipment between the pump and filter. Can I hook up a hose and run the pool water through the inline hose filter over to the pool? My thought is that it would filter out alot of the CH and any metals.

I was thinking it may be easier than draining an refilling with new H20, but I'm not sure how the other chemicals will affect the ability of the inline hose filter (ie. Salt, Chlorine, etc)...
 
I've never heard of an inline Calcium filter. Got a link?

If you're thinking reverse osmosis, it will remove everything, including salt and CYA. Reverse osmosis is also not 100% efficient - you lose maybe 25% of the water when it flushes the concentrated brine down the drain.

I battle high CH as well, and 800 is about the limit of easy management. Since I don't have a SWG, I use pool water on the lawn and refill with what I would have used on irrigation. In your case, that's not an option.

You ought to crunch some numbers and see how much it will cost to refill your pool. Some water companies drop the tier pricing on the water for a pool refill every few years if you arrange it in advance.
 
You can't just filter out calcium hardness. That would require either reverse osmosis treatment or a water softener.
 
It would be nice if it could work but the link you provided doesn't say it will remove calcium at all. The closest material it says it will remove is Lime Scale, which I take to mean solid chips of Lime, which is not the same a dissolved calcium.
 
I have the same issue with CH. And I also have SWG pool. I actually get little white flakes on the bottom of the pool that tend to accumulate in the corners. This just started to get bad last year. I have the wife vacuum to waste, I backwash and rinse often (maybe more often than necessary) and the issue has seemed to resolve itself. Mainly due to the drain and refill that happens when I need to add water. I also had an outside spigot ran that runs thru my water softener in the house. It is right by the pool for this purpose. We shall see when I reopen in the spring.

It is still crazy to me that I can have a SWG pool with 3200 ppm of salt in it and have hard water. Isn't that what a water softener does? Add salt??

Hopefully you either got a new pool guy or you are now your own pool guy (thanks to this wonderful forum). Having no CYA in a SWG pool and not thinking to add any is an issue you should not have with a "professional".


Sent from my iPhone using Tapatalk
 
bdex said:
It is still crazy to me that I can have a SWG pool with 3200 ppm of salt in it and have hard water. Isn't that what a water softener does? Add salt??
Click to expand...

Yes and no. It uses a special process that replaces calcium ions with sodium ions. This is accomplished by soaking plastic beads in a salt brine to capture the sodium, and then the incoming water exchanges the calcium for the sodium through processes that are above my pay grade.

Just adding salt to water makes it "feel" softer but does not remove anything from the water.

Also, before it is asked, you cannot hook a residential water softener to a pool circulation system. A good thought but not feasible due to the water volume needed.

From myHTC One via Tapatalk
 
Well I looked into having a company come out to run my water through their reverse osmosis trailer set up --- $550 bucks! I also ran some tap water through a carbon filter that I use for the RV and it tested at 250ppm. So it looks like a complete drain and refill with carbon filter and I should be good to go. Now to figure out how to drain it... wish I would have found this site before my pool was done and just maintained it myself... At least it will good from now on.
 

Enjoying this content?

Support TFP with a donation.

Give Support
JDC said:
Hi All,

I recently let my pool guy go and I'm in the process of balancing the water. First I found that the TA is low (40ppm) so I'm addressing that by adding baking soda. Our pool has always needed to add MA to combat high PH, and I think I just discovered why...

Next I noticed that I had absolutely no CYA as we have a SWC and our pool guy obviously didn't think we needed it. I am addressing that by adding CYA.
Click to expand...

You do NOT want to raise your TA if your pH tends to rise over time. Keep your TA low. You will use far less acid as a result. What you should use for additional pH buffering is 50 ppm Borates (say, from boric acid from DudaDiesel or The Chemistry Store or from a combination of 20 Mule Team Borax and Muriatic Acid added separately). Have you read the Pool School article Water Balance for SWGs?

Basically, TA is a SOURCE of rising pH so if the pH tends to rise over time you do NOT want to raise the TA. The borates buffer the pH without being a source of rising pH themselves. Basically, TA is mostly a measure of the bicarbonate in the water and carbonates include carbon dioxide that outgases from the water causing the pH to rise. Pools are essentially over-carbonated, but with your high CH you have no need for such a "normal" TA range. Note that even in the Pool School Recommended Levels the TA range for SWG pools is lower at 60-80 than for non-SWG pools. However, that chart assumes you have your CH lower than you do so in your case you need to compensate by having your TA be lower. You can also have a higher pH target of around 7.7 to 7.8 and don't try and lower the pH below 7.5 whenever you add acid.

So you should first add CYA to your pool since that will protect chlorine breakdown from sunlight and let your SWG not work as hard. With your SWG not having to be on as long, that will reduce the rate of pH rise due to the SWG aerating the water with hydrogen gas bubbles (and reduces any undissolved chlorine gas outgassing). Assuming a starting point of a pH of 7.8, TA of 40 ppm, no CYA, and CH of 800 ppm, then you could add the following per 10,000 gallons (you didn't give your pool water volume nor the pool water temperature).

6.7 pounds of CYA to increase it from 0 ppm to 80 ppm -- this will lower the pH since CYA is acidic
36.8 pounds of 20 Mule Team Borax to raise borates from 0 to 50 ppm -- this will also raise the pH, but split this dosage into four parts and alternate with the Muriatic Acid
25.6 cups of Muriatic Acid (31.45% Hydrochloric Acid) -- this balances against the Borax -- this should be split in dosage into four parts alternating with the Borax

You will then end up with a pH of 7.7, TA of 75, CYA of 80 ppm, CH of 800 ppm. If you need/want to lower the TA further to around 60 ppm then you would add more Muriatic Acid and aerate the water though you could just add acid over time and the TA should slowly drop.
 
bdex said:
I have the same issue with CH. And I also have SWG pool. I actually get little white flakes on the bottom of the pool that tend to accumulate in the corners. This just started to get bad last year. I have the wife vacuum to waste, I backwash and rinse often (maybe more often than necessary) and the issue has seemed to resolve itself. Mainly due to the drain and refill that happens when I need to add water. I also had an outside spigot ran that runs thru my water softener in the house. It is right by the pool for this purpose. We shall see when I reopen in the spring.
Click to expand...

If you are getting lots of flakes from your salt cell then your water is not in proper balance. Your saturation index (combination of pH, TA and CH in particular) is too high and you probably need to lower your TA level especially given your high CH. Do you use 50 ppm Borates? If not, then adding 50 ppm Borates would significantly cut down the amount of calcium carbonate scale/flakes from the salt cell because it cuts down the amount of pH rise roughly in half in the cell.
 
You can hook you auto refill to your water softner and that way you aren't continua adding even more calcium to the pool.
 
Thanks chemgeek! My pool is about 12 or 13k gal and current temp is 56

As of this morning here is what I have
FC 5
PH 7.8
TA 80
Cya 30
CH 800
I haven't read the SWG article but I will now! And also going to get some borax.
Thanks for your help!
 
JDC said:
Thanks chemgeek! My pool is about 12 or 13k gal and current temp is 56

As of this morning here is what I have
FC 5
PH 7.8
TA 80
Cya 30
CH 800
I haven't read the SWG article but I will now! And also going to get some borax.
Thanks for your help!
Click to expand...
Hang on a second...

Were you planning to lower the CH? I would recommend doing that first. My experience: CH rises about 25 per week during the summer due to evaporation and refill. So you WILL have to do something about it this year. My advice is to replace any water you plan to replace before you start dumping Borax or any other chemical in. Otherwise, it will just end up going down the drain when you do deal with the CH. And there's more to adding Borax than just dumping it in. It will drive the pH up, and you'll need to add acid to counter that. More expense to pump down the drain when you are forced to lower CH.
 
Richard is correct. If you intended to lower your CH via water dilution or reverse osmosis then that should be done first since it will lower ALL the water parameters. So there's no sense in getting the CYA or Borates up higher if you are going to dilute the water to get the CH down. What I wrote was assuming you were keeping things where they are and needed to balance more against the pH rise. It's still valid advice, but should be deferred until after you do anything to lower the CH, if that's what you do. In other words, the sequence of steps is important.
 
Brushpup said:
No it will not. But, most softeners made for residential use are not big enough in practical terms
to keep up with pool makeup demands. Generally speaking, this will normally be the case.
Click to expand...

By my calculations, a 1/2 drop in my 16 x 36 pool only equates to approximately 150 gallons. I don't think my water softner will be overwhelmed. Even at twice that level of evaporation (which we can have here in the desert), 300 gallons per day extra water use wouldn't be a huge problem for the water softner.

Trying to fill a pool with softened water would be an entirely different matter.
 

Enjoying this content?

Support TFP with a donation.

Give Support
You must log in or register to reply here.
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.
Top Bottom
Back
Jump to latest Follow Reply