Refilling Hot Tub

[Jim F]

I want to get stated on a refill. I have read, re-read, printed and posted Nitro's post "classic" post, and Chem geek's advice

But one thing isnt clear (or I am dense): what should be the order of adding chemicals to balance the different parameters? Does one start with CH? TA/pH ? When to add borax and offsetting acid? and when to add dichlor to get CYA up to 20/30?

I imagine the order is important since so many of the chemicals have effects on each other

Thanks

[Nitro]

It kind of depends on your existing water measurements. But you want to balance your water first, then Borates, then shock with Dichlor.

I check CH first. If it's between 100-200ppm I just leave it alone and make note of it.

I then check TA/pH. If TA is above 100ppm, I lower it to 60-80ppm range via aeration.

After I get my TA to 60ppm and pH is ~7.6, I add Borates to 50ppm. I use Gentle Spa, which is pH netural though.

Lastly, I shock the tub with Dichlor to 10ppm, and let it sit overnight before using.

Having great Lake Michigan water, it only takes me an hour or two to balance my water.

As far as CYA, that should be built up using Dichlor over the following week or two. Just pay exact attention to how much Dichlor you add. After you add ~30ppm FC (~25ppm CYA), switch to bleach.

After you've done this once or twice, it becomes very easy.

[Jim F]

Thanks, Nitro

2 follow-up questions:

1/ you wrote: "then check TA/pH. If TA is above 100ppm, I lower it to 60-80ppm range VIA AERATION."

Don't you mean you lower TA by adding acid? I thought aeration raised pH after using acid to LOWER TA

2/ I dont have access to Gentle Spa, so will add borates via Borax, which will of course raise pH. And this rise in pH, I need to lower with acid.

Does it make sense, therefore, to add borax BEFORE the TA/pH balancing?

[Nitro]

Thanks, Nitro

2 follow-up questions:

1/ you wrote: "then check TA/pH. If TA is above 100ppm, I lower it to 60-80ppm range VIA AERATION."

Don't you mean you lower TA by adding acid? I thought aeration raised pH after using acid to LOWER TA

2/ I dont have access to Gentle Spa, so will add borates via Borax, which will of course raise pH. And this rise in pH, I need to lower with acid.

Does it make sense, therefore, to add borax BEFORE the TA/pH balancing?

I meant to say AERATION METHOD. That is the process of adding acid to lower TA/pH, then aerating to raise pH. Then continuing the process until TA is where you want it.

If you're going to raise Borates by adding Borax, you can add the Borates instead of (or addition to) aerating the last time or two. So, if your TA is 100ppm, add acid to bring TA/pH down. Then add Borax to raise pH, instead of aerating. If your TA is really high (>200ppm), do this after you get TA down to ~100 by the acid/aeration method.

To summarize, adding Borax is similar to aerating in that it will raise pH, but not TA so much. Therefore you can use Borax instead of aerating. But only do this toward the end, because after the Borates are added to the tub, it will make it more difficult to raise pH via aeration.

The question for you is, where is your TA at now?

[Jim F]

The question for you is, where is your TA at now?

Nitro, TA is about 120/130

pH is 7.5 /7.6

But CYA is over the top (200+) since I was using dichlor before I learned from Chem Geek, you and others about CYA build-up

So I will soon drain the spa, and start over, and hence my question about order of adding chems

PS: even with high TA, and CH at 200 too, Pool Calc's CSI is -0.18, which is a desired reading , I believe

[Nitro]

If you plan on going the Dichlor/Bleach method, you'll need to lower the TA to ~60ppm. Otherwise, you'll have trouble keeping your pH under 8.0. With TA at 60, CH at 200, Borates at 50 and pH at 7.8, SI is -0.12 (which is ok and where I'm at).

Regarding Borates: Assuming 350 gal tub, in order to get 50ppm Borates, you need to add 20oz Borax. In order to counteract that, you need to add 10oz Muratic Acid. That's quite a bit. If you're going to use Borax, instead of a pH nutural product such as Gentle Spa, I'd recommend pre-mixing the Borax and acid in a 5 gal bucket of water first before adding it to the tub. That way you won't have the wide pH swings.

This is the reason I just purchase a pH balanced product (i.e. Gentle Spa), because of the hassle, and having to buy more acid. BTW, you can buy ProTeam Supreme PLUS, which is the same as Gentle Spa in bulk. A 5 lbs bucket for $25 should last you a couple years or more. To me it's a no brainer.

[Jim F]

Nitro, I may have mentioned somewhere earlier in a post that I live in Italy. (no offense to any Italian readers here, but this forum and its experts are a much better source of intel than what I can get anywhere here)

But... buying name brands isnt easy, and usually impossible. Its hard to get a handle on what ingredients are in different products available locally. Which brings me to this question:

In Gentle spa and pro team Supreme plus, the active ingredient for borates is "boric acid". Wiki tells us that boric acid is borates mixed with sulfuric acid, which I guess is why it is pH neutral.

I havent seen advice on adding "boric acid" to get borates into a tub or pool. Admittedly, it means working with acids but we are kind of resolved to doing this anyways to lower pH etc

Nitro, can u or anyone else comment on boric acid? (I am sure I can find that locally) and speculate as to how much is needed? it may be that different sources of boric acid have different percentages of borates , of course

[Nitro]

Gentle Spa is boric acid with a little sodium carbonate (soda ash) to balance it. It has the same effect as adding Borax and acid. If you want the exact chemical process of what's happening, Chem Geek would have to be the one to detail it.

As far as where to buy Boric Acid overseas, I wouldn't know. You may find it in a local Chemistry Store, or Online here. The Chemistry Store looks like they will ship overseas.