Nitro

MPS doesn't require a "Threshold". Just add it as needed. Keep in mind MPS will read as CC, even though it actually lowers it. I'd say check your Chlorine Demand (CD), by shocking to 10ppm then testing FC 24 hours later without using the tub. If CD is above 50%, give your tub a GOOD shock by doing the following: 1. Add 2 cups Clorox Bleach, and 2 oz MPS. 2. Let the jets run for an hour. 3. Measure FC. 4. Cover and let sit overnight. 5. Calculate CD by measuring FC 24 hours later. Compare CD to prior reading. 6. Check pH, and adjust TA if needed. After this shock you may need to let it sit another day or two before using it, but your water should be like new. The reason your CC (and CD) are high is because you're not using enough Chlorine compared to your CYA. Therefore, I recommend you DOUBLE (you read that right) the amount of Chlorine you add after your soaks. That means if you've been adding 4 oz Bleach after a soak, add 8 oz etc. Until you refill your tub and get CYA down to 30 ppm, you need to use more Chlorine. Lastly, DO NOT be afraid to add chlorine to your tub. The statement, "Seems like a lot to put into the tub all at once?", is what you need to overcome. The question is not how much Chlorine you ADD to the tub, it's how much Chlorine your tub NEEDS. Give your tub the amount of Chlorine it needs, no matter what the amount is.

That's fine if it's only a couple using the tub. However, if you have guests it's kind of a pain to get them to take showers before soaking. And it's a real pain to get them to go in naked. The time/trouble you guys spend worring about contaminanting your tub, more than makes up for the supposed little maintenance. Lately, most of the time I don't even bother showering before soaking. I find if enough chlorine is used during/after soaking, I have no problems. But, I'm glad it's working out for you guys. Keep up the good work.

I'd say as long long as pH is stable at 7.6 you'll be ok. However just remember, the lower the TA, the faster pH will drop from the same amount of acid. e.g. TA is a pH buffer, so the lower TA is, the less buffer effect it will have.

Read my links below.

Water is balanced (alk is bit low: 50/60, but pH is very stable at around 7.6, Hardness around 240). Using Bromine (always around 3-4). Water is about 2 months old. Have an ozone system. Thanks. I tend to agree with Dr. Spa, High TDS. Your Calcium Hardness (I assume that's what you're referring to) is kind of high. Do you have well water by chance?

It's called sluggish water. Three questions: 1. Is your water balanced? 2. Are you using enough sanitizer? 3. How old is your water?

No one can know for sure, but it can't hurt! Just remember, the Deconamination procedure is only the first step. The next step is to KEEP your tub sanitized. Read the Maintenance link below for the proper way to maintain your water using Chlorine. Also, read the link about Chlorine Demand (CD). The key is to keep Free Chlorine (FC) above zero at all times, and CD as low as possible (i.e. your baseline). If you do this you tub should be safe. However, there is a chance you could have a senitivity to the chemicals, hot water or the jets.

You can add any Calcium increaser, but only if you need it. i.e. CH is well under 100ppm. You need to measure it exactly using a drop test kit. Read my links below for a better understanding of spa water maintenance.

Dan, the main point is regardless of what causes this phenomenon, we all agree on the easist solution, just change the water. Bart, you bring up something interesting. I wonder if it would be a good idea to soak new filters in a bucket of chlorinated water before using them in the tub. It might cut down on some water issues.

I get mine at a local Spa/Pool store, Leslie's (I know the manager). However, if you use the Dichlor/Bleach method (see link below). The dichlor you get will last a very long time.

Keep Shocking! When you're CYA gets to 30 ppm, switch to Regular Clorox bleach. In a nutshell....if your chlorine usage is high it's because you are killing stuff in your tub. Once it is all dead you will see your chlorine usage (demand) drop to proper levels. I helped a buddy with his pool once and we added of 75ppm chlorine over the course of 2 days and it finally stabilized to 5ppm FC at the end of day 2....so if your tub is dirty...you will be burning through the chlorine. Exactly!

CBB77, after you change your water, and while maintaining it exactly the same as you do today, report back to us how much longer the water lasts. I guess Hottubdan needs more proof.

I'll repeat! My new tub's water lasted one month, with much less use than today (My tub is used twice as much now than the first month). I maintained my water exactly the same as I do today (as a matter of fact, I use less Chlorine today than I did back then). SOMETHING was different with my new tub's water than after the first water change. If you're trying to convince me, or anyone else different, it isn't going to happen. If you don't believe new tubs secrete oils (or something), just say so. I'll let others debate you. But from my personal experience, and many other users on this and other boards, it's a fact. Unless of course you have another explanation, other than a newbe using the tub too much. Which doesn't fly, because I've helped new tub owners in person, with the same results. And I'm no longer a newbe.

As Paul said, you can use the tub, but just be aware you'll need more (3X) Chlorine to get the same effectiveness. Just use Bleach now, until your next water change. Then follow the method at that point (i.e. CYA ~30ppm) There is no problem with filling with soft water, and adding Calcium (which BTW makes it harder). The other benefit is the Water Softener will remove Iron and other sediment.

It's called Chas' Law. My documentation is from pros and new users that post on this and other sites. And also my own personal experience with my tub when it was new. My water lasts MUCH longer now than when the tub was new, and we use the tub more now.

Keep Shocking! When you're CYA gets to 30 ppm, switch to Regular Clorox bleach.

If this is a new tub, you're better off draining completey and refilling. New tubs secrete oils from the plastics in the plumbing etc. that cause issues. Your next fill will last much longer.

Here's my opinion. Think of Chlorine as being a manual (stick shift) transmission, and Bromine as being an Automatic. You have more control of the Chlorine level, and Bromine is more like set it and forget it. If you plan on using the tub often, Chlorine might work for you well. OTOH, if you plan on leaving your tub for long periods (over a week) unattended, Bromine might be the better choice. Some peope use Chlorine in the summer, and Bromine in the winter. I'd say try Chlorine now, then on your next water change, try Bromine. OR get a Salt Water Chlorine Generator and get the best of both worlds.

No one (or poll) on here can decide which method is right for you. The only way to know for sure is to try both of them. I suggest trying one for a few months then switch, and try the other.

Jim, The manufacture is printing that info for the general population, which they believe is too stupid to add calcium increaser. If you fill your tub with soft water, then add Calcium you're ok. CYA is like a Chlorine buffer. Without any CYA, Chlorine will be too strong. However, as CYA increases, the effectiveness of Chlorine will decrease. A CYA between 20-50 ppm is ideal. If CYA is 100ppm then you need to use three times as much chlorine to get the same sanitation as if CYA was at 30 ppm. There is a method called Dichlor/Bleach where you use Dichlor for a week or two to get 20-30 ppm CYA, then switch to Clorox Bleach which has no CYA. Check out my link below for more info on this method.

Never let your FC get to 0. So that means keeping adding chlorine (i.e. Shocking) until CD is 50% or less.

Is your water balanced properly? You can add Metal X now or wait. I don't think it will matter. Also, do you have a water softener? If so, next time you fill your tub, fill it with water coming from the water softener. It will reduce metals. Just be sure to add Calcium, cause it will reduce that too.

Simon, you can still get a good baseline reading if your water is only a week old. Just give it a good shock with MPS (1-2 TBS) and 10-20 ppm FC. Let it sit for a couple days without using it, then test your CD. BTW, your CD will stay at your Baseline if you use enough Chlorine.

You don't want to leave 50-100ppm FC in the tub for more than a few hours. You could do as Mike says and do step 1 with existing water, if the tub isn't empty. You could use Hydrogen Peroxide to reduce the FC level after Step 6, but I personally don't like that idea. Also, you can skip the Spa Flush until your next refill, and just do the Super Shock. Remember though, this decon (super shock) procedure should only have to be done one time. If you maintain you water properly, you'll never have to do this again. That is with the exception of the Spa Flush, which can be done 1-2 times a year.

Because if you super shock, and have high levels of chlorine, the Spa Flush won't be effective. BTW, the Spa Flush is not required to do a Decon., just recommended to really give the tub a good cleaning.