New product to remove calcium hardness??

Total hardness and calcium hardness in pool water.
Scale, calcium buildup, hard water and scaling problems.
Ca

New product to remove calcium hardness??

Postby Ca » Wed 24 Nov, 2010 10:41

No scaling, just a very fine white powder that settles to the pool floor. Of course the pump isn't working during the treatment. Once all of it has settled to the bottom, (clear water on top and cloudy water at the bottom) you carefully vacuum to waste. Top off the water level, readjust the chemistry; there is no scaling, whatever you didn't vacuum goes back in solution.


User avatar
mas985
Swimming Pool Pro
Swimming Pool Pro
Posts: 199
Joined: Tue 08 Sep, 2009 10:40
Location: Pleasanton, CA, USA

New product to remove calcium hardness??

Postby mas985 » Wed 24 Nov, 2010 14:34

Forgive me for sounding sceptical but is this just a theory or have you actually tried this and the scale did not collect/stick to the pool surface? Also, what did you use to get the PH so high and how did you test for it?

Would it not be better to have the calcium collect in the filter with circulation instead of on the pool bottom?

I had often thought this might be possible but was too chicken to try. The consequences would be quite severe. If it works, then it might be a good opportunity to add borates at the same time since that could be used to raise the PH.
Mark
Hydraulics 101 ; Pump and Pool Spreadsheets ; Pump Ed 101
18'x36' 20k gallon plaster/gunite pool, 1/2 HP 2sp pump, Aqualogic PS8 SWCG, 420 sq-ft Cartridge Filter, Solar Panels, 6 jet spa, 1 HP jet pump, 400k BTU NG Heater
DC35

New product to remove calcium hardness??

Postby DC35 » Thu 25 Nov, 2010 09:25

I think that you could use a large sheet of plastic as a liner to prevent scale from forming on the walls. You could use sodium hydroxide to raise the pH and precipitate out the calcium as calcium carbonate.
TH

New product to remove calcium hardness??

Postby TH » Thu 25 Nov, 2010 16:36

The technique is frequently used in Europe, the product that is sold specifically for this purpose is simply *drumroll* . . . sodium oxalate.

No plastic sheet required or anything like that; you just follow the manufacturer's directions (very similar to what has been posted here). Basically the mechanism is an ion exchange between calcium and sodium. The resultant precipitation is calcium oxalate.
joshpooltech

New product to remove calcium hardness??

Postby joshpooltech » Tue 18 Jan, 2011 15:24

removing calcium hardness if you have to much im assuming this product is all about?the best way is to remove some water and add water.but if a person is worried about scale or anything along those lines,using the right amount of muriatic acid in a pool is key.if u have a concrete pool whether u have gemcoat,marcite,peb tech etc u want ur ph at 7.4 or 7.6 but dont be content with 7.6 for to long.realistically ur levels will fluctuate but keeping it at 7.4 is ideal.if u have a liner or fiberglass then u keep it at 7.6. but if u have calcium buildup whether its leaching or scale,then u treat it with muriatic acid anywhere from a half a gallon to a gallon and brush the walls with the proper brush,if u have a concrete based pool use a all stainless steel brush,and a fiberglass or liner always use a nylon..but these products they have out nowadays.u never can have a gaurentee with them,always know that as a customer and a person who does pools or owns a store.i have dealt with loads of product in the pool industry and if it works once then it works if it doesnt then save ur money.if u r stain treating in some cases u need to use a product more than once but with stain treating if u dont have progress with it then the best bet is to refinish the pool.
czechmate
Swimming Pool Superstar
Swimming Pool Superstar
Posts: 401
Joined: Sat 16 May, 2009 09:20
My Pool: 16 x 32 gunite21000 gal., Diamond Brite Blue, Swimquip XL pump, DE36
Location: Texas

New product to remove calcium hardness??

Postby czechmate » Wed 19 Jan, 2011 22:57

[quote="joshpooltech"]but if a person is worried about scale or anything along those lines,using the right amount of muriatic acid in a pool is key.if u have a concrete pool whether u have gemcoat,marcite,peb tech etc u want ur ph at 7.4 or 7.6 but dont be content with 7.6 for to long.realistically ur levels will fluctuate but keeping it at 7.4 is ideal.if u have a liner or fiberglass then u keep it at 7.6. but if u have calcium buildup whether its leaching or scale,......................

Certainly one of the longer sentences I have ran across lately.
1. Right amount of acid is hardly a key to potential scale problem.
2. PH of 7.4 is not necessarily ideal if you have high CH and CYA and facing bad CSI.
3. I was under impression that leaching is loosing calcium out of plaster, opposite to buildup.
4.I am still looking for that backyard BBQ recipe for Carolina pull pork, though you covered just about everything else...... :?
czechmate
Swimming Pool Superstar
Swimming Pool Superstar
Posts: 401
Joined: Sat 16 May, 2009 09:20
My Pool: 16 x 32 gunite21000 gal., Diamond Brite Blue, Swimquip XL pump, DE36
Location: Texas

New product to remove calcium hardness??

Postby czechmate » Thu 20 Jan, 2011 18:14

I did a little research on the Caltreat which is the brand name of this chemical early last summer.
It was not easy, since the active ingredient is NOT named on the bottle. After I finally got hold of the MSDS sheet,I discovered that the active ingredient is the same one, as the one in Calgone product, used to soften water for washers. After months of searching for boxed powdered Calgone product, which until recently was sold in every major food chain store from Target to Walmart, I found out YOU CAN'T FIND IT!! You can't even find it online, with one overpriced exception. Coincidence?? Hardly. So I will still remedy my CH the old fashion way. Control the CSI with PH,TA, salt and borates as long as I can and than drain 60-70% water(in the dry weather) fast and refill. Taking in account the complicated preparation of water required for this Caltreat to work and the fact, that it will do nothing to my high CYA, draining is still a BARGAIN with guaranteed results!
czechmate
Swimming Pool Superstar
Swimming Pool Superstar
Posts: 401
Joined: Sat 16 May, 2009 09:20
My Pool: 16 x 32 gunite21000 gal., Diamond Brite Blue, Swimquip XL pump, DE36
Location: Texas

New product to remove calcium hardness??

Postby czechmate » Thu 10 Mar, 2011 08:23

I just wanted to add some interesting facts i found about the Calgone powder, which by the way, is again on the market in 40 oz box. Cost about 6 bucks.
Here is an interesting section from a water treatment article.

"Calgone which contains SODIUM HEXAMETAPHOSPOSPHATE (NA 6 P 6 O 18) and similar commercial products remove water cations including calcium ions, by causing them to become part of a larger soluble anions.
Calcium ion from hard water +Hexametaphosphate from NA6P6O18 = Calcium Hexamataphosphate anoin."

As I said in my previous post this ingredient is the main Cal-Treat ingredient. Not listed on the bottle of course. Pool industry is always protective of their chemicals. Otherwise they would be selling regular baking soda, instead of Alkalinity-up.
I am going to try a box of this and test CH after. If it works I could limit the trichlor and use calcium hypochlorite as the main source of chlorine. Leslie's sells 100 pound bucket of CalHypo with 73% available chlorine for around $1.50/pound. Sure, it is not as convenient as a puck, but chlorine demand will stay much lower.
Richard, since this is down your alley, I would sure appreciate if you look at this, if it has any credibility.
Thanks!
chem geek
Pool Industry Leader
Pool Industry Leader
Posts: 2382
Joined: Thu 21 Jun, 2007 21:27
Location: San Rafael, California

New product to remove calcium hardness??

Postby chem geek » Thu 10 Mar, 2011 14:02

Sodium hexametaphosphate is the least stable of the polyphosphates and is also more expensive than most. It is a reasonably strong sequestering agent for calcium. In water, it can break down into sodium trimetaphosphate and sodium orthophosphate so the main side effect is increasing orthophosphate concentrations in water. Other metal sequestering agents can also inhibit scaling without such side effects.

If you are able to find 12.5% (or 10%) chlorinating liquid or 6% unscented bleach at reasonable prices, that would give you a chlorine source that won't increase either CYA nor CH.

Note that you can certainly start a swim season with a somewhat lower CH and use Cal-Hypo since doubling the CH only increases the saturation index by 0.3 units. For every 10 ppm FC added by Cal-Hypo, it increases CH by at least 7 ppm. So at 2 ppm FC per day, after 6 months this is an increase of around 250 ppm which isn't so terrible if you started with 200 and ended up with 450. You wouldn't need a sequestering agent in this case, though you would need to start out with fill water that wasn't high in CH.
czechmate
Swimming Pool Superstar
Swimming Pool Superstar
Posts: 401
Joined: Sat 16 May, 2009 09:20
My Pool: 16 x 32 gunite21000 gal., Diamond Brite Blue, Swimquip XL pump, DE36
Location: Texas

New product to remove calcium hardness??

Postby czechmate » Thu 10 Mar, 2011 15:45

Thanks Richard.
I really prefer not to mess with the bleach. I have looked at this option many times and even the Clorox brand is only 6%, while most cheap brand never have percentage posted on the label.
Also the storage and handling is not the what I prefer. If this Calgon thing works and I can hold CH at around 300-350ppm and CYA around 40-45ppm than at higher water temperatures around 88-90F all i need to watch is PH and TA to keep CSI at safe levels. Since my CYA is at 100 now, I will be draining about 60% pretty soon. Than I will see if this experiment will work. At this price of Calgon which is a fraction cost of Cal-Treat, it is worth trying.

Return to “Hard Pool Water & Scale”

Who is online at the Pool Help Forum

Users browsing this forum: No registered users and 0 guests