newbie hottub?

[jodyliebing]

Hi All!! Not sure if anyone will know me from the pool side of the forum but I LOVE TFP. They helped me fix my pool and I swear by them!! Well its getting about time to cover the pool and retire to the hottub!! I have had my tub for 5 or 6 years with no real major episodes beside the fact that I never feel like its really clean. I HATE the way it smells and compared to my sparkly pool it does not compare. I am going to start by decontaminating. We do have a (ozonator) not sure if thats spelled right. I have always used bromine and shock in the pool. I would LOVE to use bleach if I can. I am clueless so can anyone steer me in the right direction after my fill?? I also use the tf 100 test kit.

 

[linen]

Start by looking at this post: http://www.troublefreepool.com/how-do-i-use-chlorine-in-my-spa-or-pool-t10095.html

I use that method and my water is crystal clear and if I give it a couple of minutes to outgas after opening the cover and before getting in, there is really no smell I notice. I too do not like the smell of bromine tubs.

 

[chem geek]

The only modifications to what is described in that link are 1) you usually want your TA to be at 50 ppm for pH stability in a spa that has aeration jets and 2) the use of 50 ppm Borates is a must, not optional, since the pH rise in spas is much more likely and much more problematic in terms of scaling, especially in the gas heater.

 

[jodyliebing]

Thanks ! Probabally start next week and will have lots of questions. Seems more complicated than my pool!

 

[chem geek]

The main part that is more complicated than the pool is the initial decontamination to get rid of biofilms if the spa was continuously maintained properly. After that, it's similar to the pool except the much greater aeration and hotter temperatures requires the lower TA and use of borates. Once you get things set up, it's as easy as the pool -- you just add bleach every day or two just as you do for the pool. The other big difference is in the amount of bleach you add -- in a spa the bather load is high so you add an amount of bleach after your soak that is in proportion to your bather load.

The other complication in a spa is an ozonator. They work well when the bather load is high and you use the spa every day or two since they lower chlorine demand by oxidizing bather waste. However, if you don't use the spa every day or two, then the ozonator increases chlorine demand because it reacts with chlorine.

 

[linen]

chem geek brings up a good point about the ozonator. Do you know if yours can be turned off? If it can, that is probably the best thing to do if you don't use the tub often.

 

[GuinnessPhish]

Regarding borates being required in a hot tub....


can't you use muriatic acid to lower pH when necessary? I've not added any borax to my hot tub, which I've had for over a year, and generally, my pH stays relatively steady.

 

[chem geek]

If your pH is stable in your tub, then you don't have to use the borates, but there have been some newbies with hot tubs who were not diligent in watching their pH and TA levels and they got terrible scaling. So just to keep things simple, 50 ppm TA with 50 ppm Borates is what I'd say is recommended -- so perhaps not required, but the current article says they are optional and I wouldn't say that, at least not for hot tubs.

Do you have aeration jets and do you use them in your tub? If so, how often?

 

[GuinnessPhish]

I do have aeration jets....

but I don't use them too often....

guess that accounts for my relatively steady pH.

 

[jodyliebing]

well we dont use our tub every day maybe 2 times a week. I will look into turning it off. It was just installed 2 years ago. Do most of them have the capability of turning off manually?? I also tested my well water last night and it is at 200. Should I fill with half soft water half well water??

 

[chem geek]

Unfortunately they don't generally have controls for turning them off. This is one of those things where we need an article with instructions for people to enable/disable their ozonators in a safe way in various spa models. I don't have a spa myself so don't know how to do this. I suspect that there are wires to the CD or UV unit that generates the ozone that could be disconnected or, better yet, a switch cut into place that would make it easy for you to turn it on or off (though you can disable it to be off, turning it "on" would still only go on as designed, so during circulation pump cycles, for example).

 

[jodyliebing]

ok. Well if anyone might pass by this thread I would appreciate any feedback. My HT is a sundance 500 gallon about 8 yr old. Thanks for your input!!

 

[jodyliebing]

Just done a new fill on my hottub today. I am trying to adjust the TA by the instructions I got from the forum. My TA is at 70. My CH is 220. I am having a hard time using the pool calculator, getting diff #s. Could anyone tell me if a TA of 70 is correct with CH of 220?? Also does not look like i can disconnect the ozonator. I had my pool mastered using TFP. I feel like im staring over with the hottub!!!! HELP. Also next step is adding dichlor to raise CYA. Should I just use the powder stuff that I USEDto use in my pool untill I hit 30ppm?

 

[chem geek]

If you are doing the Dichlor-then-bleach method, you should have the TA drop down to 50 ppm. The Dichlor is net acidic so will lower the TA some, but you'll probably have to add some acid and aerate to get it down lower. Don't forget to add the 50 ppm Borates after you get the TA down to 50 ppm. And why do you think the CH has to be so high? It should be around 120-150 ppm which is enough to prevent foaming, but minimizes the risk of scaling. The hotter water temperature in a spa makes scaling in the heater more likely so a lower saturation index is needed (though with the low 50 ppm TA that will help). The reason for the lower TA than in a pool is that there is a lot more aeration in a spa (plus the smaller volume has a higher surface area to volume ratio so more outgassing) plus it's hotter water that outgases faster.

 

[jodyliebing]

I didnt adjust the CH I filled with well water and thats what my well water is. I thought that was ok? Or is it too high.

 

[chem geek]

If you get your TA down to 50 ppm, then the CH you have will be OK. The CH of 220 ppm gives a saturation index roughly 0.15 higher than a CH of 150 ppm. A spa with water at 104ºF has a saturation index 0.2 higher than at 80ºF which is why one generally targets a lower CH and TA, especially since the pH will tend to settle in higher if you use spa jets.

 

[jodyliebing]

ok, I have my TA down to 50 but my PH still is hreading high???

 

[chem geek]

Did you add 50 ppm borates (say, with boric acid) yet? They act as an additional pH buffer that do not contribute to a rise in pH. Also, don't try and lower the pH below 7.5 and if it wants to be around 7.8 and slows down rising there, then let it settle there.

 

[jodyliebing]

well it looks like I overshot it, TA was at 20 this morning, added baking soda!! No, I have not added borates or dichlor yet, I will be getting it today. I read to use "gentle spa" for borates. Correct??? I also ended up adding about 30oz of muratic acid total. Should I be concerned about adding that much acid is dangerous to the skin??? Also could I just use borax and MA to create borates in my spa??

 

[linen]

Once you add the Muriatic acid what matters is where ph of the water is at (Muriatic acid quickly gets broken down into other components one of which is salt).

Pro team gentle spa is fine to use (a little pricey around here imo), straight boric acid, or borax/MA are all fine.

What is your tub volume?