Well water or soft water, conflicting info..

[Topline Mike]

I've read on a different site that using soft water, or water after it's gone through my water softener, would be better to use in a hot tub, as opposed to just filling from the well.  I would probably need to add calcium to the water, which doesn't seem very hard to do, right? 

 In some other literature that I have, it says that soft water is actually worse that untreated water.  It states, "such water is aggressive and will actually attack metal fittings and heat exchangers...".  This literature recommended using a sequestering agent to control high calcium levels and other metals. 


I understand that everyone's well water is different.  I know I have a fair amount of iron in my well water.  My Taylor test kit K2106 is not here yet, so I don't know where I sit with pH, TA, or CH.  If anyone could give their thoughts on this, it would be much appreciated.  I have read other threads on the subject of high iron in their water, but I didn't find an answer to which method of filling is best. 

[Tman122]

Ive always though that the PH/ALK tell you whether you use hard or soft. Test your source water to see where it starts. Your shooting for 7.0-7.4 PH and a 100-120 ALK but some say lower on this? Beats me. You may be best mixing both soft and hard to dial it in. Let us know.

[TwinCitiesHotSpring]

Ive always though that the PH/ALK tell you whether you use hard or soft. Test your source water to see where it starts. Your shooting for 7.0-7.4 PH and a 100-120 ALK but some say lower on this? Beats me. You may be best mixing both soft and hard to dial it in. Let us know.

this pretty hits it spot on, test both water "sources" and post your numbers and we can help you out.  In my immediate area most people use a 50/50 mix of outside "hard" and inside "soft" and that generally gets them into the 100-150ppm range for calcium which is ideal

[rosewoodsteel]

Mike, my water is definitely too soft.  I just ordered something to take care of that. Calcium up (or something along those lines).   All the other readings are within parameters.   I'm afraid to say, I haven't dug into the tester kit yet. I've just been using the test strips (easy peezy).    I'll experiment with the kit this weekend.
Tman, be gentle with me.

[Tman122]

While the re-agent test kits are a pain. Once your used to it you will understand your water better. Eventually we all get to the point after hundreds of water cycles we understand and can anticipate the waters needs sometimes with out testing but once or twice a month.

[Topline Mike]

My taylor test kit arrived in the mail today.  Here are my results:

Well water:
pH, 7.2
TA, 400
CH, 280

Soft water:
pH, 7.4
TA, 390
CH, 0-10

I used some strips that the previous owner gave me.  I got a pH of about 8, and the TA only went to 240, which was the color match I had.  I don't have much faith in those cheapo test strips, too vague I guess. 

Now the question is, how do I lower my TA with dry acid or muriatic acid without lowering my pH too much?  I would guess I'll have to add a little at a time and aerate after every addition.  I was under the impression that if your TA was high, your pH would be high also.  I guess not.  I will fill the hot tub with 3/4 or so with my well water, and the rest with soft water to drop my CH to around 150 ppm.  How's that sound?? 

[Tman122]

Go 50/50 and we'll see if we can lower that TA slowly and see what it does to the PH

[kurt6137]

Very simple, use well water, but use a filter specific to hot tub fills. Get one from your dealer or online. Once filled, check your water and add hardness as needed. The filter provides the perfect set up for balancing your water, I used to have my hot tub filled with spring water, but got tired of paying $125 to $150 a clip, which the water often was dirty and had my filter working overtime, since filling with the well and filter, easy peasy.

[rosewoodsteel]

Is adding hardness a good thing? My owner's manual councils against it. 

[Topline Mike]

  The filter provides the perfect set up for balancing your water 

kurt, I don't think those filters will lower your Total Alkalinity? 

rosewood, I have read that a calcium hardness of 150 is best, but 150-400 is OK.  If you have next to zero calcium hardness, I would definitely add calcium chloride.  I would strongly suggest you buy a Taylor test kit for your spa to get accurate readings.  The Taylor kit, K2106, comes with a water chemistry guide to read, and also a watergram.  You want your saturation index to be at 0 for balanced water.  See picture below of the watergram. 

[rosewoodsteel]

Thanks, Topline.   I'm embarssed to say that I have the kit, but I haven't used it yet.  That will change, this weekend.

[kurt6137]

Yes Mike, I didn't mean to say the water would be perfect, of course i have to add alkalinity increaser, decreased, ph increaser, ph decreased as needed. I test my water once a week. I just saying that filter is a good place to start, if your going to use well water.

[Topline Mike]

I filled the tub today.  I used about 2/3 well water, the remainder was from the bottom spigot of my hot water heater (soft water).  I just tested CH, and I'm right where I want to be, 150ppm.  Working on lowering my pH right now with acid.  TA still way up there. 

[Tman122]

Go slow, soak and enjoy.

[Topline Mike]

Being this was my first hot tub I ever tried to balance the water in, I did go very slow.  I ended up added muriatic acid 13 times to get to where I am now, which is a pH of 7.7, a TA of 100, and CH of 150.  When I initially tested the pH in the fresh fill water, it was at 7.2.  I aerated for a 20 minute cycle, which is how long the pumps run on my jacuzzi.  The pH after that was way high, probably around 8.4, or so.  Using http://www.troublefreepool.com/calc.html, it told me to add 2 oz of acid to lower my pH to 7.7.  So I started adding 1.5 oz of acid at a time.  Well, the numbers seemed to be coming down bit by bit, but I didn't want to overdue it.  After I was done, I realized that I could have added 8 oz on my first acid addition, and been fine.  With the acid causing the pH to come down, and the aeration to cause the pH to go up, it can be a bit tricky.  So, I am saying that you can use more acid to start than what the Pool Math site tells you to.  I ended up adding around 24oz of muriatic acid. 

We've spent around 4 hours in the hot tub already, and the kids are loving it.  Happy days.