Newbie Water Chemistry Questions- Sundance With Clear-Ray

[GaTub]

Our new Sundance Hartford was installed a little over a week ago and I already have water chemistry questions. I understand the Clear-ray UV system that we have is brand-new for Sundance so we are probably "guinea pigs" of sorts. And the manual that came with the tub provides very little information on chemicals, referring to the authorized dealer for advice. All it really says is that chlorine should be maintained above 1.0 with the Clear-ray system installed. There is no installed ozone system.

The technician shocked with Brilliance granulated chlorine right after filling and also added a Nature2 mineral sanitizer cartridge (silver nitrate) in the filter housing. He told us to add a cap of the chlorine granules once per week, and 1/2 cap of Brilliance potassium monopersulfate oxidizer before using the tub. He told us that the the chlorine will probably be at 0 before the weekly add but the water should stay clear.

Everything was fine through last weekend although I added about 1/2 cap of chlorine granules at the end of each day because the reading on the test strip kept on dropping to 0. This brought the chlorine up in the 3-5 range. Then I was out town on business Tues-Fri and my wife didn't add any chemicals while I was gone. When I opened the cover this morning I saw the water was noticably cloudy with a green haze. All I have done so far is added more of the chlorine granules.

The tub has been in regular use- at least once each day. We also discovered that our golden lab mix will sneak in for a swim if the cover is off and we are not watching. Now that we realize this we are watching to keep her out, but I am sure that her swims have not helped the water chemistry. Maybe if we could teach her to shower first...

All the other readings on the strip appear to be in the normal range. My first step will to order a good test kit (Taylor K-2006) but have some basic questions. I will also ask the dealer for advice- it will be interesting to see how it matches up with what I get here.

• Should I be seeing the chlorine drop to 0 overnight?
  
• Do I need to add the oxidizer before each use? Is this the "MPS" that I have seen references to here? Is it possible to add too much of this?
  
• What do I need to do to get the water clear again?
  
• What should the initial free chlorine level be after "shocking" with the granulated chlorine?
  
• I've seen recommendations here about using household chlorine bleach. How do I know if the brand does not contain other additives that don't belong in a hot tub?
  

I am a chem engineer and have worked on industrial water systems so have an appreciation for the chemistry involved. But I'm a hot tub newbie and this is a different ball game. Would appreciate any advice.

[chem geek]

He told us to add a cap of the chlorine granules once per week, and 1/2 cap of Brilliance potassium monopersulfate oxidizer before using the tub. He told us that the the chlorine will probably be at 0 before the weekly add but the water should stay clear.

His bad advice was the primary source of the problem. The UV system does not oxidize bather waste and he told you to use way too little oxidizer and you should never let the sanitizer level get to 0 (except perhaps during the latter part of your soak, but then add more right afterwards). Roughly speaking, with no ozonator, every person-hour of soaking in a hot (104ºF) tub needs about 3-1/2 teaspoons of Dichlor or 5 fluid ounces of 6% bleach or 7 teaspoons of non-chlorine shock (43% MPS). In addition, there is a daily chlorine loss of around 25%-50% depending on the age of the water (based on cumulative bather-load) and what type of sanitizer you use.

So you not only were not using enough oxidizer, but weren't adding it regularly enough or high enough to last through multiple days. You've got a few choices if you want to properly manage your tub. If you use the tub regularly, every day or two, then the Dichlor-then-bleach method should work well for you and is described here. If you aren't able or willing to dose every day or two or to shock higher if you are going to be gone for several days, then you should consider using the 3-step bromine method described in this post. Regardless of which method you use, you need to get yourself a proper test kit such as the Taylor K-2006.

Right now, you can try shocking with 6% bleach, but you might have biofilms depending on how long the water went south. On your next drain/refill, I suggest you use Spa System Flush before you dump the water. That will help remove biofilms and greasy chemicals that may be adhering to hard to reach places such as piping. Once you get into a routine properly maintaining your water, you shouldn't need to do this again.

[GaTub]

That makes perfect sense- the UV will help with micro growth but does not keep the water "clean." The chem adds that were recommended might work fine with the UV for a tub that sees little use, but during the past week ours has been used a good bit.

I already ordered the Taylor K-2006 kit. I've looked over the the links before but without a proper test kit they are of limited use.

I took a sample of the water to the dealer after posting yesterday. They said everything was in the proper range and suggested that I shock with MPS. They also gave me a bottle of a product called "Scumshield" and told me to add a few oz. We just went through the annual pine tree pollen event (everything here in the SE turns yellow for a week or two) and he said that the pollen has definitely not helped.

I just took a look and the water looks a whole lot better- not yet 100% clear but no more green tint. I'll keep the chlorine level up using the dichlor until my kit arrives and go from there.

[PreservedSwine]

"Roughly speaking, with no ozonator, every person-hour of soaking in a hot (104ºF) tub needs about 3-1/2 teaspoons of Dichlor or 5 fluid ounces of 6% bleach or 7 teaspoons of non-chlorine shock (43% MPS)."

Is this spa over 700 gallons?

[waterbear]

The technician shocked with Brilliance granulated chlorine right after filling and also added a Nature2 mineral sanitizer cartridge (silver nitrate) in the filter housing. He told us to add a cap of the chlorine granules once per week, and 1/2 cap of Brilliance potassium monopersulfate oxidizer before using the tub. He told us that the the chlorine will probably be at 0 before the weekly add but the water should stay clear.

You are NOT using chlorine at your primary sanitizer. You are using silver/MPS (potassium monopersulfate) activated by the hot water as your primary sanitizer so it is correct that the FC would be at 0 ppm for much of the week. This system does require that there is a residual of MPS in the water at all times and the chlorine is used as a supplemental "shock" weekly or "as needed" (more than weekly). In your case UV is not really doing much of anything except perhaps helping break down some persistent oxidation byproducts when you do shock with chlorine (which is the main advantage to UV in an INDOOR pool or a spa on chlorine. If the spa can be exposed to sunlight when being shocked with chlorine the additional UV unit is superfluous.)

Here is the instruction manual for the N2 system. When followed it does work but it is not my first pick for spa sanitation. My suggestion is read it and follow the 'recipe' and forget that you have a UV unit installed since UV is not a residual sanitizer so it is not really doing much at all for you.

• Should I be seeing the chlorine drop to 0 overnight?
  

Yes, Chorine is not your primary santizier, it is silver ions and Potassium Monopersulfate potentiated by the elevated temperatures in the spa. You will not maintian a chlorine residual with this system.

• Do I need to add the oxidizer before each use? Is this the "MPS" that I have seen references to here?
  

You might need to specifically add MPS before each use since you are using a Nature2 system. It has nothing to do with the UV. Period.

• Is it possible to add too much of this?
  

You need to maintain a MPS residual in the water to keep it sanitized. Normally the MPS is added after the soak unless there is no residual left in the water beforehand. MPS tests as combined chlorine so a simple OTO drop test which tests total chlorine can tell you if you have nay present before you soak. MPS is an irritant and sensitizer to too much can be a bad thing and can cause irritation or allergic reactions.

• What do I need to do to get the water clear again?
  

If you are going to continue using the N2 cartridge then you need to shock with chlorine until the water is clear (I would use bleach since it is unstabilized chlorine--no cyanuric acid), possibly higher than the amount outlined in the Nature2 instructions, and then follow the Nature 2 instructions to the letter.

• What should the initial free chlorine level be after "shocking" with the granulated chlorine?
  

10 ppm or above when tested afer shocking. The spa should be left uncovered and circulating until the FC drops below 10 ppm.

• I've seen recommendations here about using household chlorine bleach. How do I know if the brand does not contain other additives that don't belong in a hot tub?
  

It should be regular chlorine bleach.

Read the label. It should be 5.25 % or 6% sodium hypochlorite (and might possibly list some additional sodium hydroxide, salt, and/or sodium carbonate) and should not be scented, thickened, 'outdoor', HE, 'detergent, colorsafe, or other 'specialty" bleach. House brands from grocery stores or big box stores such as Walmart are often a better choice since the major 'brand name' bleach adds sodium polyacrylate to their consumer bleach (but not their 'professinal' janitorial bleach) to help prevent dirt from redepositing on clothes. However, sodium polyacrylate is also a common ingredient in pool and spa water clarifiers so it really is not a problem if you choose the 'brand name".

[GaTub]

First off, I discovered the seperate water chemistry section after posting. This thread probably belongs there but I am also new to this forum...

This spa holds 470 gallons.

I found the box that the Nature2 cartridge came in and lo and behold, the instructions were inside. And yes, it certainly looks like they started me up on the N2 system. But without instructions on the importance of adding MPS, and without MPS test strips. I'll discuss with the dealer tomorrow.

[PreservedSwine]

Another option:

Dichlor is a great sanitizer, as well as ozidizer, but the amount of stabilizer in the dichlor becomes an issue over time, so try to use it sparingly. Try adding about 1/2 to 1 teaspoon dichlor before each use, then 2-3 TABLESPOONS of MPS after each use.

Right after use is an ideal time to oxidize or sanitize the water... At that moment, the spa needs sanitation more than any other time.

I would continue the weekly or bi-weekly shock with MPS instead of Dichlor as well.

[waterbear]

I would continue the weekly or bi-weekly shock with MPS instead of Dichlor as well.

Not if you are depending on the silver and MPS to be your primary sanitizer. If you are going to use chlorine with supplemental MPS shocking for high organic load you DO NOT NEED THE NATURE 2 CART AND TIIT REALLY MAKES NO DIFFERENCE THE IN FC LEVELS YOU NEED TO MAINTAIN. Sorry for shouting but many do not get this! If anyone wants proof of this just look in the current N2 instrctuions about substituting diclor for MPS and compute the FC levels. You will find that you are maintaining the spa at the same FC levels that are required without the N2 cart! The old 'recipe' for N2 (that Zodiac has to change maybe 6 years ago) used a very low FC level with weekly MPS shocking. It did not work to keep the water clear and sanitized. The new 'recipe' depends on the fact that metals will catalyze MPS at elevated water temperatures so it becomes an effective sanitizer but still needs 'as needed' shocking with chlorine .

IF you are going to use chlorine as your primary santiizer I would look into the dichlor/bleach method since it eliminates the problem of CYA buildup.

[PreservedSwine]

I agree, but his current routine isn't sufficient to deal with bather load, and he already has the cartridge...

[waterbear]

Yes, but he would 1 cap of dichlor be the same as the required 3 tablespoons for his spa? would 1/2 cap of MPS be the same as the 2 tablespoons that he needed to add? Was he told to shock with chlorine 'as needed' (such as when he discovered the Lab in the tub or when he discovered the water was green?) Was he checking for a residual of MPS before eahc soak (special strips are not needed since MPS will test at combined chlorine on DPD tests (most test strips) or as total chlorine with an OTO drop test (cheap and readily available!)?

My point is that the problems occurred because the N2 protocol was not properly followed (not uncommon with N2, btw). By adding the additional chlorine daily (and then ignoring the spa for a few days) and NOT keeping an MPS residual in the water it basically was a badly maintained chlorine spa, not a silver/MPS spa. Even with the high bather load and the dog in the water silver/mps should work if done properly (just as either chlorine or bromine would work under these conditions if done properly!)

[GaTub]

Good debate, and yes waterbear's last post summarized exactly what happened. I am not going to place any blame but need to get it right. The cap is right at 1-1/2 tbs so it would take 2 of them to chlorine shock up to 15 ppm using the dichlor. And 1/2 cap of MPS is much less than recommended in the Nature2 instructions. At least it doesn't seem that they were trying to sell me chemicals.

After treating over the weekend the water doesn't look all that bad, but its still not as good as it should be. We are staying out for now and I just put 3 tbs of dichlor in to see if that will completely clear it up. The test strips that they gave me only show FC so I don't have a way to measure MPS. My test kit is supposed to arrive by next week and that should help.

[chem geek]

The rough guidelines for oxidizer amounts are independent of spa size since they relate only to bather load.

As for testing MPS, you can either use MPS test strips or you can test MPS levels with a chlorine test kit. A DPD chlorine test kit will measure MPS as Combined Chlorine (CC) because MPS does not react with the DPD dye but does react with the potassium iodide in the R-0003 reagent for the CC test. The FAS-DPD chlorine test kit (such as in the K-2006) may measure the MPS as Free Chlorine (FC) because the MPS reacts with the FAS drops so if there is any chlorine then it will stay stuck with color until the MPS is gone, but if there is no chlorine at all then the MPS won't show up (i.e. the sample is clear) until you add the R-0003 reagent for the CC portion of the test. There's an MPS interference remover reagent, but for what you are doing I don't think that's necessary.

As for the chlorine test strips, I'm not sure what they measure, but if it's just DPD for FC, then the MPS won't show up.

[waterbear]

The easiest way, IMHO, to test for MPS in a N2 system is with an OTO test for total chlorine Let it develop for about a minute but if it is yellow (above the 3 ppm yellow on the comparator) you have enough MPS residual in the water.

[hjames710]

We also discovered that our golden lab mix will sneak in for a swim if the cover is off and we are not watching.

Lmao. That's funny, my golden is terrified of the tub, he stands on the steps, and looks in while I'm in there. Once I tried to dip his paw in, there was NO WAY he was having that, he pulled back as hard as he could and ran across the yard. Haha. Our old Lab never even looked at it.

I'm still cracking up

[GaTub]

After some heavy chlorine shocks and not using the tub for a few days the water looks crystal clear again and not using up the chlorine like it was. My K-2006 kit arrived last night so I am ready to do some real testing and get into some sort of routine. And when I decide to dump and re-fill I will be ready to do right. If there is any follow up to this story I will start over in the water chem section since that is where this post should have been to start with.

Missy is only 2 years old and full of energy- the best natural frisbee dog I've ever seen (she trained me to throw it, not the other way 'round.) We took her swimming once when she was still a pup and she loved the water then. It looks like that hasn't changed. But she is NOT allowed in the hot tub!

I haven't said much about the Hartford tub itself- other than the water chemistry fiasco we are happy with it so far. We didn't want a lounger since I am very tall and my wife is very short. The corner seats are at different heights but all work fine for both of us. Pump 1 (two-speed) works the jets on one of the corner seats, the jets along the side seats and the waterfall. Pump 2 works the remaining 3 seats- high speed only. With both pumps on high it really works the water but there are plenty of adjustments. The LED lights that the tub came with go all around the top just above the water line with one also at the bottom. There are a bunch of color settings which are fun to play with though the strobe setting is pretty silly. There are independent air adjustments at all the corner seats and with the air open it really froths the water.

This is a 680 series tub so at the bottom of the Sundance line. We didn't want to invest any more money than needed since we weren't sure how much we would really like it or use it. Figured this would be a big step up from the no-name tubs without spending a ton of cash.

[gman]

GaTub,

I don't want to alarm you and you've already stated that your dog is NOT ALLOWED in the tub...but I just want to warn you about something you might know of already, but...the water temperature in a hot tub is too high to be safe for dogs. Dogs cannot dissipate heat very easily. The high temperature of the water in a hot tub will raise your dog's body temperature to dangerous levels very quickly and dogs have difficulty dissipating the heat from their bodies once their temperatures are elevated. Your dog may love the water, but unlike the cooler water in a pool or lake, the hot tub is not a good swimming environment for your dog. Good luck with keeping him/her out.

Good luck also with getting your water chemistry issues resolved. This forum's Water Care section is loaded with useful information and a great resource. The success I've had in maintaining trouble-free spa water is due to the generosity of knowledgeable participants and regular contributors like chem geek and waterbear, et al. I know there are many happy hot tub owners because of the research and contributions of these forum members. I can't thank them often enough.

Happy tubbing,

gman

[GaTub]

Like I said, she is NOT allowed in the tub- especially after the water quality trouble she helped cause. But thanks for letting me know there is a concern for her health.

Just went through the testing regimen with the K-2006 kit (reminded me of organic lab classes in college). As a result I am starting a new post in the chem section. Think I'll title it "Should I just start over?"

[hjames710]

Your water must be changed about every two months anyways. I myself would change the water after my dog took a dip, but it's up to you. Freshwater is always the nicest anyways, feels more comfortable.