Starting up a hot tub

[dogsbody]

@DangerBoy - hey, Roj.

We just installed a used Dynasty out in the woods (read: well water). We did the initial fill with soft water just 'cause that's how the house is plumbed - it was convenient. Now I get that doing so leads to a pile of potential problems, starting with just trying to get the pH into range. The trouble is that our water is harder than he!! - I just dragged out the pH/TDS meter I used back in my growing days, and the well water is at least 700ppm (yes, it could probably use a calibration, but that's good enough as a rough number). So we figure it would be good to drain and refill before the ambient temp plunges and things are much more unpleasant. But what to do? I get that there's a minimum calcium level to maintain (and the residual ions from the softener to avoid), but this strikes me as off the scale, and comes with whatever else is down there, inc. a lot of iron. I don't see starting with RO water as a realistic option, given the rate at which our RO produces.

 

[BigOrangeSpa]

What about using softened water makes pH hard to get into range? I would suggest posting some numbers for others to review. It could be that your TA or other parameters are what is making the pH hard to maintain. I would imagine that as long as you add calcium hardness increaser to your softened water to get around 150ppm it should be fine, but I'm sure others will correct me if I'm wrong.

I also don't know that using a TDS meter means much in the context of a hot tub. You'll probably have a high TDS out of your softened water as well, since there will be a lot of salt. TDS doesn't mean your water is hard. I would guess your CH is high from a well though, just saying the 700ppm probably doesn't mean much of anything to determine what you should do to the water. You'll need to measure calcium hardness directly.

Do you have a good test kit like the ones described here? Swimming Pool Test Kits Compared

 

[dogsbody]

Hi, folks. Brand new here, and to tubs. 2010 Dynasty (400-500 gal) just acquired and installed over the past couple of months.

We're in the Alberta foothills, and on a well. I initially filled with soft water (because nobody told me to do otherwise) and we coasted for a month or so without any chemicals because it's just a couple of us using it lightly. But I knew I was going to have to get on the chemistry detail, and it looked like the consequences of (regular NaCl) softening were going to be significant. So we drained and refilled with well water. I knew from my hydroponic growing days that our water is HARD - I recall TDS readings of 1200ppm, which drove me to growing exclusively with RO water. RO is not a realistic option in this case because the production is (if you'll pardon the pun) glacial.

Yesterday, when filled and up to temp, my TDS reading was around 900ppm, so I gave HEDP (Spa Essentials Balancer Stain and Scale Control II) chelation a go in 1 oz increments. It seemed to be bringing the TDS reading down, but stalled around 600ppm - by that point I'd dumped in 8 oz and figured I'd better stop. I get that chelation isn't the final answer because though the minerals/metals are out of solution, the chelation products can redissolve, but at least it'd be a start. But not only could I not get lower than 600, but by this morning it'd bounced back up to 900.

So I'm really lost here. Can anything be done to water this hard to establish a stable baseline (I gather 200-250 ppm Ca is desirable) that I can then work from?

 

[BigOrangeSpa]

Did you see my reply here? Starting up a hot tub

You seem to be confusing TDS with hard water. They are not the same. You should be measuring calcium hardness directly and trying to move that down (if it's crazy high). I would suggest posting a full set of test results so that folks here can help get things balanced.

 

[SJPoe]

Calcium Hardness is probably your bigger concern than TDS, as consistently high levels could lead to scaling of your heater elements etc.

Step 1 : Get a decent test kit and measure the values for CH, TA and PH accurately from the Spa and fill water.

Once you have these, the brainiacs here can figure out a plan to get where you need to go


Test Kits Compared

 

[dogsbody]

Odd - I checked before starting this fresh thread and didn't see a reply. My browser may be misbehaving.

I don't want to step in anything nasty by getting into conflicting definitions - I'm perfectly happy to go along with those accepted here. I understand the difference and the limitations of an electrical measurement. I've just been trying to use it as a rough starting point. I have a couple of reagent test kits here (old and supplied with the tub), but don't know if they're (still) any good.

Lemme bounce back to the other thread rather than trying to run both concurrently.

And... thanks.

Jonathan

 

[dogsbody]

Oh... someone's merging the two threads while I'm in the middle of them... very confusing.

 

[BigOrangeSpa]

Odd - I checked before starting this fresh thread and didn't see a reply. My browser may be misbehaving.

I don't want to step in anything nasty by getting into conflicting definitions - I'm perfectly happy to go along with those accepted here. I understand the difference and the limitations of an electrical measurement. I've just been trying to use it as a rough starting point. I have a couple of reagent test kits here (old and supplied with the tub), but don't know if they're (still) any good.

Lemme bounce back to the other thread rather than trying to run both concurrently.

And... thanks.

Jonathan

Looks like it got merged here.

It's not conflicting definitions, really. It's not possible for anyone to give you advice based on just a TDS number. TDS is total dissolved solids. It goes up when things are dissolved in the water. It can't tell you if your water is hard. Your TDS could be 500 and your calcium hardness only 50. TDS doesn't tell you what is dissolved. If you're wondering about hard water, in so much as it can cause stain and scale in your hot tub, you need to measure your calcium hardness, pH and total alkalinity. Once you've measured those things and posted them here, you'll get a lot of help balancing your water I'm sure.

 

[dogsbody]

As I said, I do understand the difference. You can see a very close approximation of my situation over in the "Starting up a Hot Tub in the Mountains" thread of a few days ago (@DangerBoy is a friend). I'm in the same mountain range, just east of the Rockies, and know from previous experience (and living out here for 25 years) that the calcium content of our well water is off the charts, so your "TDS of 500 and Ca hardness of 50" example, while valid for purposes of argument, does not apply here.

I'll get on the legit-test-kit detail right away and report back asap.

thx.mch.
Jonathan

 

[BigOrangeSpa]

Sounds good. I was just trying to illustrate that using TDS to make any sort of decisions is flying blind, not that I thought your calcium hardness was low. I bet it is really high.

You mentioned in your original post that you were concerned about using soft water. Can you expand on why that is and what you think the residual ions are doing outside of increasing TDS? Is it because of warranty concerns or something? Otherwise, I don't see why you couldn't use the soft water and add calcium hardness increaser.

If you have to start with well water, you could do a mixture of soft water and well water. You could also look into the Vanishing Act pillow. I've used it a couple of times to lower calcium hardness by a few hundred ppm.

 

[dogsbody]

Now that I've been nosing around (and speaking with a friend with actual professional expertise), I'm lost and apprehensive.

1. I need to (properly) test my water.
2. I need a proper test kit in order to test my water.
3. Test kits appear to be oriented toward either chlorine or bromine.
4. If the choice of Cl or Br is dependent on water, I need the results of the water test in order to choose the correct test kit.

So now I'm deadlocked. Reminder: This water is abnormal in that it's from a well in the mountains and extremely (Ca) hard. I can use it, or use (NaCl) softened, or a mix of the two. Though I have an RO unit here, it's just used in the kitchen and is very low throughput i.e. it'd probably take a month to fill this tub.

On the other hand, if the choice of Cl or Br is not dependent on the water, which do I choose? I sense that this is a religious argument, and have no wish to start a bun fight that may have already played out here a thousand times. Or maybe there's a FAQ on choosing that I haven't spotted and someone can direct me to.

Help!

p.s. @BigOrangeSpa To answer your questions, my early online investigations suggested that there were clear downsides to using soft water, ranging from corrosion to difficulty in balancing the chemistry due to the ion exchange products. It's worth pointing out that I tend to yell at people who say what I just said ("I read somewhere and can't cite or provide details without digging again."), so go easy on me if all that stuff was fresh cowpatty. Warranty is not an issue - this is a 15-year-old tub bought used.

 

[BigOrangeSpa]

I'll preface this again by saying that I am fairly new to hot tubs and water chemistry. I feel like I've learned a lot here, but I don't want to seem like an expert.

If it were me, I'd probably do a mixture of soft and hard water. If you test the calcium hardness from both sources, you ought to be able to figure out a mix percentage to get you around 150ppm. Alternatively, you could just use all soft water and add calcium hardness increaser. In an ideal world, you wouldn't want all the salt but I don't think it's a big deal. As far as corrosion is concerned, my understanding is that is mostly a concern with plaster and grout. It's possible it could cause some damage to the heater, but I would guess not at the level of salt we're talking about out of a softener? But really hard to know without measuring those things.

As far as bromine and chlorine goes, it seems to me to come down to your usage patterns and how hands on or off you want to be. There's stickies at the top of the forum that describe both systems pretty well. Chlorine will be pretty hands on with daily dosing (unless you also look into a salt water generator to generate enough fc for standby) and bromine you can use tabs in a floater and shock weekly.

I personally go with chlorine because I find it simpler to understand, and I use my tub pretty much every day so measuring out some chlorine and adding it after my soak isn't a big deal. If I knew I was going to be gone a lot and not able to check on things, I'd probably go with bromine.

That's about the extent of what I feel I can add. I'm positive you'll get a lot of other thoughts from people that know way more!

 

[dogsbody]

Thanks. I read both of those stickies - up to the point at which each got a little too far into the weeds, e.g. "...and when you have a big drunken party in the tub..." - and got the impression that Cl is certainly a lot less fussy. As far as the factors that might affect my choice go, here's another fabulous list:

• Our usage is light - two of us in the house, probably using it every couple of days, though we'll see how we feel about it once the ambient temperature is -20C or below. One or both of our our kids may drop by from time to time, but overall I'd guess that on average we'll be about the equivalent of one-person-daily.
• I'm not looking for any new hobbies.
• I jam econo, meaning I'm an incredibly cheap sumbitch and do almost everything myself.