First Fill of hot tub, questions on chemistry

[rayf01]

So, I got my hot tub back together with the new motor/pump and seals. This is my first time filling it, so I had the local store test my tap water, results below:


TDS: 250 ppm
Alkalinity: 110 ppm
PH 7.4
Calcium: 130 ppm
Free Chlorine 4ppm
Combined Chlorine 0ppm
Iron: 0 ppm
Copper: 0ppm


So with the above results I have a few questions:

1. With my TDS at 250, however my iron and copper at 0, do I really need to use any additive to remove metals and prevent staining upon the first fill? I have spoke to other people in the area and they never do. I did fill without it already and I also added some Calcium Hardness Increaser to try bring my calcium up to the 150-200 range so I will test that shortly, buts its the only thing I can think of for balancing right now that I need to do I believe? If I need to add the metal remove stuff, can I still do it?

2. My alkalinity and PH seem to be bang on out of the tap. Therefore I shouldn't need to add anything at all right now right?

3. Shocking and Sanitizing: I used a non chlorinated shock first tonight, I haven't added any sanitizer yet. A friend gave me chemicals from his spa that he just sold with a house. I have two types of chlorine granules. One says CHLOR on the bottle and is 65% Calcium Hypochlorite. The second says Stabilized Chlorine Granules and is 100% Sodium Dichloro-S-Triazinetrione. Which is the better one to use to sanitize my spa? I was reading that both either add calcium or CYA to the water.

Should I consider using Bromine instead which doesn't do this?

4. Is Free Chlorine the level of Chlorine I need in my spa to stay between 3 ppm and 5 ppm or is it the combined chlorine? My Free is already at 4ppm out of the tap...

5. Should a person use Chlorine or Bromine pucks in a floater to maintain the level instead of having to add granules all the time?

6. Also, how do I convert grams to something useful like cups? Or do you have to measure the weight of all your chemicals? The chemicals are all instructed in grams. Since particles from one chemical can have a higher density and weight than another should I be using a scale?

7. Will balance values change with temp? These are tested at 64 Fahrenheit as the spa heats up.

[Aquatub88]

Hello, let me give it a shot.  I have been maintaingnmynoool for 10 years and a new hottub for the past 2 months...
- The TDS tell you the combined additives in the water as you add chemicals for balancing.  In my opinion less additives is always better.  If the TDS gets too high then you have to drain and start over.   If you get a yellowish ring around the top water line that would indicate metals and you can easily correct by adding the metals reducing additive once and that should do it.
- Always balance alkalinity first and then the PH if needed.  You have perfect numbers.
- For tubs you should use DiChlor which is a highly concentrated chlorine. You only need a little at a time based on 350-500 gallons of water. Do not use pucks/tabs in the hottub and you should not need CYN treatment since the hottub does not bake in the sun like a pool does. The CYN is a stabilizer that resists the suns deteriation of the chlorine of a puck- but for a pool.
I was advised not to use Bromine; Use Dichlor
- Your Free chlorine should register between 3-5 ppm unless you are using a salt generator and then it would register lower.  The total and free chlorine should be equal.
-I would follow the directions on the chemical bottle and do a conversion based on your tubs total number of gallons.  Generally the chemical bottles make it easy allowing you to put in a cap full or a 1/2 capful per application but you need to know your gallon conversion.
- I have not seen a change in my balanced numbers as the tub got hotter.  I leave the tub at 102 degrees and knock on wood, everything has been stable.
Good luck!