Milky Blue Water After Refill

[dakotaloo]

Just refilled our Hot Springs Vanguard 400 gallon spa with fresh water (used a filter on the hose.)

(Have owned spa for a year. Never had a water clarity problem at any time.)

All 5 TriX filter cartridges cleaned in dishwasher, no soap.

Added 1 16 oz bottle of Spa Care Metal Free, 30 min full jets, before taking any readings.

Initial levels:

CH zero

TA 30

Didn't measure pH, always highly acidic, wanted to wait for reading till after raising TA

First chemical addition:

Calcium choride 14 oz, 20 minutes full jets

Moved CH from zero to 190

Water looked just the littlest bit milky after this

Second chemical addition:

Baking soda 6.8 oz, 10 minutes full jets

Moved TA from 30 to 85

Baking soda 2.0 oz, 10 minutes full jets

Moved TA from 85 to 120

Water looked terrible after this, deep milky blue, can't see bottom of spa

Third chemical addition:

Dichlor, .5 oz, 10 minutes full jets

pH at this point 7.6

Called spa dealer and explained water clarity problem.

Recommended 2oz of Bright and Clear to clear water, 1 hour full jets

If that didn't work, said to use a second bottle of Metal Free, (30 minutes full jets.)

Bright and Clear did nothing to help.

Added Metal Free (liquid, deep blue color)

Water continued to look terrible.

For some inexplicable reason, even with over an hour of aeration, new reading of pH was 7.1.

Any help understanding what is going on in the water in my spa?

Any remedy besides draining and refilling?

How do I keep this from happening again?

Very discouraged....

[dakotaloo]

Just retested water after another 30 minutes of aeration.

CH 160

TA 110

pH 7.4

Called the company that sold me the Metal Free.

Technician said that the Metal Free, in addition to sequestering metals, also sequesters calcium, and that by adding both the Metal Free and calcium chloride on the same day, I had created the cloudiness in the water.

She said that in the future, I should start by adjusting the TA and pH, then getting the chlorine to where I want it, before adding the Metal Free on the day of the refill.

Then a few days later, I should add calcium chloride to get the calcium hardness up.

She always told me that the water should clear in a few days, and that I might want to flush the filters again once it does.

Question #1. Is her diagnosis correct? And is her advice about the order in which to do things correct?

Question #2. Is she right that the cloudiness will clear in a few days? (I added a total of TWO bottles of Metal Free, on the advice of the dolt at the spa place, and a total of 14 oz of calcium chloride, based on a zero reading following the first application of Metal Free.) If it's not going to clear, and I need to drain the tub, I have to do so right away, as a nasty sub-freezing cold spell is in the forecast for these parts.

Thanks....

[chem geek]

Since you apparently used a water softener (ion exchange resin) filter on your hose for the fill water, that should have removed any metals from your water and will probably reduce some of the calcium as well. So why did you use Metal Free at all? Using a water filter to remove metals is far superior to using a metal sequestrant in the water since the latter will break down over time and can cause side effect problems as you have discovered.

Is your spa blue colored? The water was probably cloudy/milky, but the blue color might have just been the spa color showing through the cloudiness.

It is true that excessive amounts of a metal sequestrant can lead to cloudiness and it may be true that this is exacerbated when the calcium level is higher. Why did you raise the Calcium Hardness (CH) to 190 ppm anyway? That is generally too high for a hot spa unless you were to keep your Total Alkalinity (TA) very low and yours at 120 is not at all low. Using a pH of 7.6 at the time of these readings, the saturation index at 104F would be +0.26 so could cause cloudiness and even start to scale, especially in the heater (which is even hotter). If you lower the pH and the water clears up, then the milkiness was from over-saturation of calcium carbonate (i.e. the saturation index got too high).

I can't say whether the tub will clear up, but such overdosing of Metal Free isn't a good thing. It's up to you, but starting over and not using the metal sequestrant (assuming your water filter is functional) would probably be the right thing to do. You can follow the Dichlor-then-bleach method if you want.

By the way, Natural Chemistry Spa Metal Free as shown in this MSDS file is EDTA and is to be dosed at 4 ounces for 400 gallons so if you put in two bottles that were 1 liter each, then that's over 67 ounces or overdosing by over a factor of 16!!! No wonder you had such problems.

[Hillbilly Hot Tub]

I think she and chem geek are right, you CH and ALK are high, which will cloud the water. You don't need metal free usually with a pre filter, although I have one town that you do because the water is so loaded with iron.

Chem geek, some brands, such as Seak Klear metal remover have you use the entire bottle at a fresh fill, then not again till you refill the tub. Soem have you put 2 ounces a week in. Depends on the brand he has.

[dakotaloo]

"So why did you use Metal Free at all?"

I'm glad to have your clarification about the pre-filter and the Metal Free doing the same thing. When I ordered the pre-filter from a spa supply company, I did so thinking that I wouldn't need to use Metal Free/Metal Gone anymore. But when I was reading through my spa manual as I prepared to empty and refill the tub this time, this is what I came across:

'To prevent contaminants from entering the spa, Watkins recommends using the FreshStart pre-filter. The pre-filter is designed to remove unwanted contaminants such as rust, dirt, detergents, and algae from the fill water. Dissolved minerals and metals such as lead, calcium, copper and iron are not removed.'

So when I read that, I figured, "Rats, I misunderstood about the pre-filter. I can use it for debris, etc. , but I still need to get the metals out by using a Metal Free/Metal Gone product." I had explicitly wanted to avoid the Metal Gone, as I hate adding extra junk to a fresh tub of water. In the future, based on your recommendation, I'll just use the pre-filter.

"Natural Chemistry Spa Metal Free is EDTA and is to be dosed at 4 ounces for 400 gallons."

That's not exactly the product I used. I used Spa Choice Metal Free, purchased from the Spa Depot. It says on the back of the 16 oz container to use the full bottle when refilling the spa. So I'm guessing it's must be more dilute than the product you're referring to.

"Is your spa blue colored?"

Nope. Sand-colored plastic. The blue milky tint is definitely from the chemicals somehow. As I mentioned, though, the Metal Free I used was a dark blue in color, so maybe that explains it.

"Why did you raise the Calcium Hardness (CH) to 190 ppm anyway? That is generally too high for a hot spa unless you were to keep your Total Alkalinity (TA) very low and yours at 120 is not at all low. "

Now I'm so confused!! On the advice of this forum, I've been using the Pool Calculator, which lists the following goals:

CH 200-400

TA 80-120

pH 7.2-7.8

(CYA 30-80)

If I shouldn't be using these targets, what should I be doing? Or is it just that my pH should be lower?

In the meantime, while waiting to hear back from someone on the Forum, we turned the heat down to 80 degrees on the tub, assuming we would have to empty it as soon as the weather warms a bit (it was nine degrees here yesterday, with a wicked windchill on top of that.) That shifts the saturation index a bit, yes? On top of everything else, I'm hoping against hope that we haven't damaged the heater...!?

This is my first real hot tub chemistry nightmare, and I really am a bit overwhelmed by the whole thing. Still not sure what to do this next time to make sure we don't have a repeat...

[chem geek]

Now I'm so confused!! On the advice of this forum, I've been using the Pool Calculator, which lists the following goals:

CH 200-400

TA 80-120

pH 7.2-7.8

(CYA 30-80)

If I shouldn't be using these targets, what should I be doing? Or is it just that my pH should be lower?

The "Goal" ranges listed are mostly for pools which are at much lower temperatures than spas. At higher temperatures, one needs a lower combination of CH, TA and pH. The Pool Calculator will calculate the saturation index for the combination, including taking into account temperature, assuming you enter it, and you'll want that saturation index to be near zero, but not above zero -- targeting somewhat below is better (say, -0.3 to -0.1) unless you have an unusual plaster spa or tile with grout.

You should generally adjust your TA so that your pH is stable and that may mean lowering it. You would then see where your pH settles in, usually in the 7.5 to 7.7 range, and then you'd adjust your CH last.

You can probably recover from the milkiness if it is due just to calcium carbonate by lowering the pH now and then the TA over time by adding acid to keep the pH lower. If that clears up the cloudiness, then that was the problem that would now be solved. If it doesn't, then perhaps the Metal Free is causing a problem, mostly because you added twice the recommended dose (i.e. two bottles instead of one).

[dakotaloo]

We're draining the tub today (above freezing, just for today.) You wouldn't believe what the main filter looks like -- absolutely covered in a white powdery substance suspended in the liquid adhering to the filter. I think it's pretty clear the problem was largely calcium precipitating into the water.

So I'm planning to:

FILTER the refill water, to remove dissolved metals. (No Metal Free)

ADD BAKING SODA to raise both my TA and pH until I'm getting a pH reading that seems good (7.5 or so)

Wait a few days, adjust the pH if needed, calculate what CH level I need to get a saturation level at or slightly below 0 with the pH and TA I've got at that point, and then ADD THE RIGHT AMOUNT OF CALCIUM CHLORIDE to attain that level.

Meanwhile, I'm using DICHLOR to sanitize and build up some CYA, until I switch to straight bleach.

Have I got this right, chem geek?

[dakotaloo]

In your post, chem geek, you said "targeting somewhat below is better (say, -0.3 to -0.1)"

Was that supposed to be -.03? Otherwise, I'm confused again...

[chem geek]

No, I meant -0.3 to -0.1 meaning towards the negative side of zero though you could target something between -0.1 and -0.2 if you like. Most spas don't have plaster to protect and temperatures at the surface of heat exchangers in gas heaters can be 30F hotter (the water coming out isn't that much hotter, however) where scaling would be more likely as a result. As an example, a combination of a pH of 7.6, TA of 60, CYA of 30, CH of 150 and 104F would have a saturation index of around -0.2 so would be OK. A combination with the same pH, CYA and temp, but with a TA of 80 and a CH of 120 would have a saturation index between -0.1 and -0.2 which is also OK. It is far more important to not have the combination of pH, TA and CH too high since scaling can be a serious problem, as you have found out.

[dakotaloo]

Thank you thank you! Got it now.

Is everything else I laid out in the 10:47am post on target?

Hope you and yours have a wonderful ringing in of the New Year.

And thanks for your generous support of all us know-nothings.

[chem geek]

Your plan is good except you said you were going to add baking soda to raise pH and TA. Don't do that. Only add baking soda if the TA is below 60 ppm. See how your pH goes, especially after you switch from Dichlor to bleach. If the pH is stable or rising slowly, then leave the TA where it is. If you start out with a high TA, then your pH will tend to rise when using bleach. After you've got a TA where the pH is fairly stable, then you can adjust your CH higher if needed to get the saturation index higher (you can also target a higher pH, if necessary, such as 7.7 instead of 7.5).

To raise the pH with no change in TA, you can aerate the water. Note that when you are using Dichlor, the pH may tend to fall as Dichlor is net acidic when accounting for chlorine usage/consumption.

[quantumchromodynamics]

Tips on adding calcium:

Give plenty of separation between adding calcium and other chemicals. Try not to add any chemicals for at least four hours before or four hours after.

The most important chemical to be careful about is sodium carbonate and the next most important chemical to be careful about is sodium bicarbonate. I would not add calcium on the same day as adding either pH increaser or baking soda.

I also recommend that calcium additions be limited to a maximum of 50 ppm at any one time. The calcium should be mixed in a clean, plastic container and the clear liquid should be poured into the spa.

Don't add more than 4 ounces of calcium to a gallon of water when dissolving the calcium. Calcium gives off heat as it dissolves and the mix could overheat if you add too much calcium to too small of an amount of water.

[simonc]

Called the company that sold me the Metal Free.

Technician said that the Metal Free, in addition to sequestering metals, also sequesters calcium, and that by adding both the Metal Free and calcium chloride on the same day, I had created the cloudiness in the water.

She said that in the future, I should start by adjusting the TA and pH, then getting the chlorine to where I want it, before adding the Metal Free on the day of the refill.

Then a few days later, I should add calcium chloride to get the calcium hardness up.

This is an interesting thread. I don't often think about the order of adding chemicals to my tub.

In Nitro's Approach to Water Maintenance there is no mention of using a metal inhibitor. (Although, there is some discussion of using a pre-filter as a possibility, not a necessity.)

Should I use a metal inhibitor and if so when?

I looked up the prefilters. They seem to cost about $50-$60 with shipping. That's expensive, I think.

I'm on a municipal water system, but it gets it's water from wells, so our water has a tendency to be hard, but low in calcium (<100).

I'm about ready to do a refill on my tub again. I did my last refill just after joining this forum (about 3 months ago) and I've learned a lot since then. In the past, I always added the metal inhibitor (Stain & Scale Inhibitor by Spa-Kem) on a new fill. However, I never added calcium before. I did add calcium a few weeks after the current refill to increase it to about 100.

In reading many posts on this forum, this is the first one that I've seen discussing adding a metal inhibitor. So ... should I add metal inhibitor on my next refill and if so when? Also, the directions on the Spa-Kem bottle says I should add it every time I add fresh water to my tub. I've never done this. Should I?

By the way ... I've used a metal inhibitor on each refill and I've never had any VISIBLE scale or staining problems on my Jacuzzi brand. The tub surfaces look pretty much like new even after four years of use. I don't think I should mess with success.

- Simon