Water Chemistry Help

[Quickbeam]

I was wondering if someone could give me some help with my water chemistry? We got our new tub delivered yesterday (Jacuzzi J-345) and are now waiting for the electrical to be hooked up.
I am just testing our tap water in anticipation of our first fill into the tub. We have fairly hard water at our place, so when we were building, we had a water softener installed. Our hot tub is on our roof deck, and we have two taps up there. We have one tap that is supplied with our hard water and the second tap is supplied with water through the water softener (note that our water is regular municipal water - it is not well water).
On my initial testing I took half the water from the water softened tap and half the water from the non softened tap. These are the readings I ended up with:

PH - 7.9
CH - 100 ppm
TA - 139 ppm

I am trying to gain some insight on what to do without chasing my tail so to speak. When we initially paid for the tub, the chemist at the dealer said the only two things he is concerned about is that we keep our PH balanced and our sanitizer current. He said he would not be all that concerned about the CH. Note as well that we are going to try using hydrogen peroxide as a sanitizer. I have read that hydrogen peroxide will not affect the other readings, but am not entirely sure about this???

I know from the numbers above that my PH is too high and my CH is too low. I have also read that harder water will increase the PH. So it seams that if I put less softened water in the tub and more hard water to increase the CH, that my PH is also going to increase. I think I have this correct??? So, I am wondering if I should try putting more than 50% soft water in the tub to bring the PH down and just not be concerned about the CH? I am thinking this because of what the chemist at my dealer said re don’t worry so much about the CH. I guess I am trying to get my water balanced by just using the source tap water if that is possible. Also, the Jacuzzi manual warns not to put too much soft water into a tub, but I found a couple of articles online that say soft water will not hurt a tub.
Can anyone tell me if soft water will hurt a tub?

Any thoughts or suggestions on any of this would be much appreciated.

[Topline Mike]

I'm assuming you had the spa store test your water?  I don't know how to get a TA reading of 139ppm. 

I would test the soft water and then test the hard water, separately.  This is what I did so I had an idea of how much of each supply to fill up the spa.  My soft water had a CH of 0-10ppm, and my hard water had a CH of 280.  I filled the tub with about 2/3 hard water, and the rest soft water.  I ended up with a CH of 150.  From what chem geek has posted, a CH around 150 will keep the foaming down.  Other than that, it's not very important.  My pH and TA levels were the same for soft and hard water from my well.  You can't adjust the pH by using more soft water or more hard water.  I would just try to get the CH between 100 and 200 and call it good. 

When the tub is full, aerate the tub with jets and air controls.  This will raise the pH to where it wants to be.  I had a TA of 400ppm, and a pH of 7.2 on my initial fill.  This doesn't make sense, since a high TA means a high pH.  Well, after aerating the tub for 20 minutes, my pH went sky high, as it should have.  I then added muriatic acid for the next 6 hours in small doses to bring down my TA.  Add acid, aerate, add acid, aerate.  It could have went a lot quicker, but I didn't want to overdue it, because it was my first ever hot tub water balance.  I brought the pH down to 7.8, and my TA was at 90.  Today, about 6 weeks later, I am sitting at a pH of 7.6, and a TA of 50 to 60. 

I read an article that said soft water was not good for your tub, but in another forum, the boys said it does not have a negative effect on your tub.  A low pH or a high pH will cause problems, from what I have read. 

I thought you bought a test kit?? 

[meriflower]

I always bypass our water softener when filling our spa and is what I was told by two different spa dealers that I purchased from (1 Marquis, the other Bullfrog).  IIRC it's due to the softener taking out the calcium.  Water low in calcium can cause corrosion to your spa's plumbing and heating.  I just add stain & scale to deal with the hardness.  I suppose one could use the softened water and add what the softener took out.

[Spatech_tuo]

I always bypass our water softener when filling our spa and is what I was told by two different spa dealers that I purchased from (1 Marquis, the other Bullfrog).  IIRC it's due to the softener taking out the calcium.  Water low in calcium can cause corrosion to your spa's plumbing and heating.  I just add stain & scale to deal with the hardness.  I suppose one could use the softened water and add what the softener took out.

If you have specifically a hard water source I would do a 50-50 add.