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Hard/Soft water pros/cons

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Greetings all,

I'm planning to purchase a hot tub in a week or so and I'm researching the pros and cons of using soft water.

I'm on a well with liquid rock hard water. I use a water softener to make life bearable as it easily destroys laundry, dishwashers, and other appliances.  I understand there are chemicals to lower hardness and to raise hardness.

So, now I'm wondering which is the lesser of two evils. I have yet to find any chart or guidance as to which is better. If my well water is so high I have to invest in huge quantities of chemicals to bring it down, I could well be better off with soft water and raise the hardness with less chemicals. I will need a test kit to confirm this, but I suspect I can save money and effort if I start with soft water and raise the hardness. After all, my water softener can be programmed to produce less soft water on demand. It may take some experimenting, but it could save me time and money in the long run.

Just checking here first before I go off the deep end and hoping that some folks here might have experience testing both.

Suggestions appreciated.


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My current water hardness test kit calculates (if my math is correct) 620 ppm, or 35 grains/gallon, very hard water.

My water softener brings it down to less than 1 grain/gallon, which is quite soft.

So then I now need to decide which is the best path for treatment. Go up or down. Which is easier to treat, a tub full of hard water, or a tub full of soft water? If I can adjust my water softener so that it produces 150 ppm, i might be in the ball park and it would also save me some salt.

Interesting problem.

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The big experiment has started.

I adjusted my water softener to use less salt. I have started a spreadsheet to track the changes. I will be testing my water daily for changes over time.

My starting point is now 600 gallons per charge instead of 200 gallons. That should cut my salt usage back even more. I currently add salt about every 2 to 3 months. If this works, it should save me a lot of time and money.

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Use softened water and bring your CH to around 130 ppm if it is lower than that. There are no chemicals that will lower CH. CH above around300 ppm can lead to scale deposits on the tub surface.

If you current softener is producing water of 1 grain that is about 17 ppm.

On 5/3/2021 at 11:51 AM, Water Wurld said:

That should cut my salt usage back even more.

not really. The salt dissolves to produce a saturates solution in your salt tank and the same amount of brine is used for each resin recharge. The only way to lower salt usage is to change your backwash frequency or the pounds of salt setting which controls the amount of water in the brine tank if I am not mistaken and therefore the amount of salt that will dissolve to produce a saturate solution. IF your softener valve does true on demand backwash based on water usage  or is a metered valve and not a time clock on a set schedule you will probably not see a difference. If your unit uses a timeclock you can set it to backwash less frequently to save salt but that is usually not a good idea.

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waterbear, thanks for your comments. This is all new to me, and so a big experiment.

Testing daily and still waiting for change. Salt usage should drop as I am reducing the recharge intervals. Still not sure if gpg will increase or not. I turned off the clock based charge, and the regeneration is now based on usage only. I started at 600 gallons, and now down to 400 gallons before recharge. It may take a few more days before I see it recharge. Test results still showing 17ppm.


There are no chemicals that will lower CH.

Peat moss works to lower CH, but not an easy (or wallet friendly) method. If I can safely raise the CH using soft water, that is my goal. So, I'm waiting to see what, if any, fine tuning I can do with my water softener can achieve.

Hot tub arrives next week, so I'm collecting as much information as I can before it arrives.

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22 hours ago, Water Wurld said:

Peat moss works to lower CH

Peat moss lowers pH, not calcium hardness. I've used it in aquariums for that purpose. It will also acidify soil. The ONLY way to remove calcium is by an ion exchange medium as found in a water softener or by reverse osmosis. A sequestrant can chelate calcium but does not remove it from the water. The easiest way to raise calcium is by adding calcium chloride, which is what calcium hardness increaser is. IF you are using chlorine be sure to get a pool/spa grade of calcium chloride because much of what is sold as de icer contains enough sodium bromide to convert some of the chlorine to bromine. If you are using bromine it probably does not matter much since yo want to create a bromide bank anyway.

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22 hours ago, Water Wurld said:

If I can safely raise the CH using soft water

soft water is water that does not have CH (calcium hardness) or magnesium hardness either. Water softeners work by replacing the calcium and magnesium in your water with either sodium or potassium, depending on whether you are using salt or potassium chloride in your brine tank.

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And the reason why?

Are any of the mineral sanitizers worth installing? My local dealer has the chlorine activated copper mesh kit for sell as well, but I'm not keen on chlorine.

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Copper stains and turns hair green. Period! End of story!. Metal ions are not fast acting primary sanitizers with the exception of silver nitrate with MPS and HOT WATER. (Nature 2) but it also requires chlorine shocking so it's not totally chlorine free.

All metal systems, whether active ionizers, passive systems like Nature 2 or SpaFrog, or copper sulfate and/or silver nitrate based 'alternative' sanitizers which often have the word 'Blue' in their names because of the color of copper sulfate (which are, in fact, nothing more than algaecides) still require using an oxidizing primary sanitizer for fast kill times and action against viruses. The same goes for enzyme additives and qauaternary ammonium based 'serums' and such. They are an unnecessary added expense. Some of these products say that you can use a reduced chlorine or bromine level but in actual practice this lower level of fast acting residual sanitizer (chlorine or bromine) is quickly depleted by the bather load. A tub has a small quantity of water and a large bather load. Metal ions (call them minerals if it makes you feel more warm and fuzzy but in fact copper, silver, and zinc are metals. They do have a limited use as algaecides in swimming pools under certain conditions but would still not be my first choice because of their drawback. While they are classified as pesticides with an EPA registration number they are not EPA registered fast acting residual sanitizers.

Fun facts: EVERY person that enters the tub involuntarily urinates about 5─10 mL in the water and involuntarily releases about 10─25 mg of fecal matter (Courtesy of Taylor Technologies). They also sweat and sweat and urine are almost chemically identical. The water to bather ratio in a tub (most are under 500 gallons) is extremely small when compared to a pool (average size of most residential pool is 15,000 to 20,000 gallons) or even a swim spa (normally in the range of 1500, to 2500 gallons) so a fact acting residual sanitizer is a must!

IF you are going the bromine route I suggest 3 step bromine since you are in the US according to your IP address. (Sodium bromide is no longer available in Canada so alternative methods are needed).

1. Add sodium bromide on filling to create your bromide bank in the water

2. oxidize (chlorine is the preferred oxidizer but MPS can be used. My preferred chlorine source is Sodium Hypochlorite, also know as pool chlorine and also as liquid chlorine laundry bleach (such as Clorox) Once you create a bromide bank the chlorine oxidizes the sodium bromide into hypobromous acid and no chlorine is in the tub.

3. put in a floater with bromine tab to maintain the bromine santizer levels in proper range. (Fun fact, most bromine tabs and 1 step bromine granules are mostly chlorine).

1 hour ago, Water Wurld said:

I'm not keen on chlorine.


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Thanks for your excellent feedback. I will digest the information.

I'm not keen on chlorine because my wife and I don't care for the smell. However, I do understand it's shock qualities and I am in favor of it's use as an oxidizer.

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New test results on water softener...it jumped from 17 ppm to 357 ppm today.

Not what I expected, but now I know I really can't fine tune my system like I thought I could.

I'll adjust it back so that it works like it used to. But, I can find that sweet spot so that I'm not wasting any more salt than needed.

It was set at 25 gpg and recharging at every 200 gallons. Currently at 12, so the sweet spot is somewhere in between. I'm going to guess 400 gallons may be best between recharges. But, I can live with adding CH from <= 17 ppm as my starting point. This is so very interesting.

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Taylor K-2106 test kit and the Pentair Chlorine/Bromine Floating Dispenser have been ordered.

Hot tub arrives in a few days.

Can't wait to ease my aches and pains.

I wonder what tastes better in a hot tub, beer or wine?

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15 hours ago, Water Wurld said:

wonder what tastes better in a hot tub, beer or wine?

The reality is that drinking while in a hot tub is dangerous and not just because you might get drunk. The heat actually intensifies the effects of alcohol. Both cause blood vessels to expand  and therefore cause a rise body temperature. This can lead to dehydration which can cause heat exhaustion. Symptoms include confusion, fatigue, headache, nausea, and extreme sweating.


Most Hot Tub Manufacturers and Dealers caution against drinking and tubbing.







Sorry to be a buzzkill. My advice is to do your drinking the night before an then use the tub to help combat that hangover the next day. There is evidence that soaking for 20 to 25 minutes and relaxing in the water will help improve the circulation in your body and help it remove the toxic alcohol metabolites that are causing your symptoms. Just remember to stay hydrated because the heat of the tub can cause dehydration! This means water, NOT the "hair of the dog"! 😉


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Thanks for those links, I'll check them out.

Stopped at Wally Wurld today and I was surprised they had all the chemicals I needed except for the bromine. Dirt cheap too.

Now looking for bromine source.

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