First time setup (or: does temperature matter?)

[Nackle]

I am going to fire up a new hot tub tomorrow for the first time. This is my first hot tub and I've tried to absorb as much as I can from TFP. In the hot tub setup instructions from the manufacturer where it says to balance the water, the dealer has handwritten in "warm water first". The Hot Tub Basics page on the TFP wiki puts balancing the water before heating it up. I'm wondering why the dealer might have wanted me to warm the water first.

To be clear, this is my plan, mostly taken from the Hot Tub Basics page.

1. Purge the tub: fill with tap water, sanitize water with bleach to reach FC of 10*, add Ahh-some, let jets run for a while. Clean foam then drain.
2. Fill tub with tap water.
3. Sanitize with dichlor to FC of 3**. Eventually aim for a CYA of 30.
4. Balance water to reach ~50 TA and ~7.4 pH.
5. Add boric acid to reach 50ppm borates.
6. Reduce CH with Vanishing Act. (This is a Hot Springs tub with their SWG which they document to prefer an extremely low CH of 25-75 ppm.)

If water temperature actually matters, I guess I would wait to balance between steps 3 and 4.

Does the water temperature actually matter? Does the rest of my setup plan sound right?

* I read somewhere that Ahh-some needs an oxidizer so that the stuff it dislodges actually gets destroyed. I'm happy to skip the bleach here if it isn't necessary.

** This FC is lower than the Hot Tub Basics page notes, but I thought TFP preferred to aim for a fairly low FC.

 

[JoeSelf]

#1 Run the jets with Ahh!some until nothing comes out. Might take more than one or three. Let it sit a little while between jet runs. New tubs are gross. Take a look at their purging videos.

I didn't heat the water when I purged. But it was warm out.

CH helps with foaming, I'd go easy on the reduction. Everything else looks good.

Start heating when you refill after purging.

 

[phonedave]

AhhSome works fine in cold water, but it dissolves much easier in hot/warm. If you are purging with cold water you may want to dissolved the AhhSome gel in a cup of warm water first.

My advice is to forget trying to balance TA & pH in a hot tub. In my experience the volume is too small and things get way to finicky. I just dose with acid daily to keep my pH in range. After 7 - 10 days the TA and pH get to a balance point naturally and my pH stays pretty much stable. Whenever I try to rush the process by driving the TA to where I think it should be, it ends up taking longer and being a lot more frustrating.

No idea why your directions say to have the water warm before balancing, unless it is because if you are using dry chemicals they may dissolve easier - maybe.

I keep my CH high (300 ppm) to avoid foaming, but having it low is not going to make things unsanitary - it just may have excessive foaming.

 

[Nackle]

This morning I made a dumb mistake and pushed my FC way too high. I've been dialing everything in over the past two days and it's gone great. Really nice looking numbers today. I'm gradually adding dichlor to push my CYA up.

After a nice soak last night, my FC was 2 this morning. I used PoolMath to calculate the amount of dichlor to add in. And then... I added 10x that amount. Instead of 0.2 oz of dichlor, I added 2 oz of dichlor. Sigh.

So, PoolMath tells me that I've raised my FC by 18, dropped my pH by 0.7, and raised my CYA by 17. I aerated for 20 minutes and just tested my water. I get the following stats.

• FC: 20
• CYA: 25 (calculated)
• pH: 7.9 (This surprised me. I did aerate for 20 minutes after adding the dichlor, but I wouldn't have thought my pH would go up so much, especially with my TA where it is. I measured this both with the optional digital pH meter from TFTestKits and with the TF color tester.)
• TA: 50
• Borates: 0

I've already turned off my SWG.

I have some ideas to fix this, but thought maybe I'd check in first.

• Add liquid stabilizer to raise CYA to 50. I had in mind aiming for a CYA of 30 (I can't actually remember why) so this exceeds my target, but maybe it's fine?
• Tell my kids to go pee in the hot tub. (Kidding.) (Mostly.)
• Leave it open to the sun and hope the sun + time uses up the FC.

What's the best approach here?

 

[JoeSelf]

If it's sunny open that puppy up! Can always add hydrogen peroxide.

Hydrogen peroxide to lower FC.

 

[Nackle]

Hydrogen peroxide did the trick! (Sunlight was working too slowly for me.)

Using the rule of thumb on the page you linked, I needed to figure out how much 6% bleach to raise the FC by 10. I added that many ounces of 3% H2O2. It dropped the FC a little more than I expected—13 instead of 10–but that was fine. Thanks!

 

[RDspaguy]

I'd go easy on the reduction.

Due to the locally high ph within the salt cell as it generates high ph chlorine, it causes scale on EVERY salt cell out there, even if the pool/spa has an overall low ph. By reducing calcium you reduce scale and thereby extend the lifespan of the cell. Also, there's that little note in the paperwork on this new $18k spa that says improper chemical maintenance will void your warranty. Just saying. While under warranty, do what the manufacturer says.
No, they don't care if you struggle with foam, they care if you destroy expensive equipment because you're afraid of some foam.

but I thought TFP preferred

Is TFP going to cover your repairs denied by warranty due to chemical misuse? Just curious.
Follow manufacturers recommendations while under warranty. Good advice or bad, if it's not manf advice, it's wrong as far as they are concerned.

 

[Nackle]

Is TFP going to cover your repairs denied by warranty due to chemical misuse? Just curious.
Follow manufacturers recommendations while under warranty. Good advice or bad, if it's not manf advice, it's wrong as far as they are concerned.

Surely TFP will cover any of my repair costs!! I paid $0 for site access and downloaded their free app too. If that doesn't create an ironclad liability relationship, I don't know what does.

More seriously: I wasn't sufficiently clear. The "Hot Tub Basics" page I mentioned is the one in TFP's wiki. My manufacturer specifies a range of 1-5 FC, which I'm following (except for the accidental dosing to 20 ).

I did indeed use their (expensive!) Vanishing Act pillow to reduce my calcium to their recommended levels. My salesman mentioned in passing basically what you said: high calcium will cause faster wear on the salt cell. The cell isn't warrantied anyway, but I'd like it to stay good for longer!

So far, no foam. If that eventually crops up, will it be because soap-like contaminants in the tub?

 

[RDspaguy]

Usually foam results from oily contaminants that you bring in on yourself, such as fabric softener, hair conditioner, detergent residue, makeup, sunscreen, etc. It can also result from organic contaminants, sanitation byproducts, equipment malfunctions, and poor water balance.
Calcium in the water inhibits bubble formation, but by no means prevents it. I'm not enough of a physicist to tell you why, but it has to do with surface tension.