Cya = 100Ppm

[waterbear]

My ACE owner's manual states I should have the following:

Parameter ----------Target -----------Min-Max---------------What my level is

Salt : -------------1500ppm--------1000ppm-1750ppm ------------1620ppm

CH : ---------------50ppm ---------25ppm-75ppm----------------50ppm

TA : ---------------80ppm-----------40ppm-120ppm----------------50ppm

pH : -----------------7.4------------------7.2-7.6---------------------7.6

Chlorine: -----------3ppm-------------1ppm-5ppm-------------------4ppm

I also have 50ppm of borates in my spa (gentle spa). My dealer said it was safe to use with the ACE system.

I know I am within range of my TA, however I was under the assumption per Nitro's guild to water maintenance that my TA being so low could create an "unstable situation". However my main concern is how on earth I can lower my pH to 7.4 while not also lowering my TA even lower. I read Waterbears post on lowering TA, however I am still stumped because I really need to raise my TA and also LOWER my pH. So the only way I can see as an option is bring my TA back up to 120ppm, then trying to just somehow lower my pH to 7.5 without dropping my TA below 60-80ppm in the process.

I'm stumped

I would not bring it up to 120 ppm. I would not go over 80 ppm or you are going to have problems keeping the pH low enough! pH rises on it's own because of outgassing of CO2 and teh aeration caused by the hydrogen bubbles generated in the salt system increase this cause of pH rise.

Also, it takes much more acid to lower TA than to lower pH so if you raise the pH up to about 70 or 80 ppm (still high IMHO), wait about 24 hours for pH to stabilize, then use your acid demand test to lower the pH to the desired target (with borates that would be about 7.6 to 7.7) you should be fine.

The trend in a salt system is for pH to rise. Low TA slows this down. Also setting your target pH at the high end slows down pH rise since the lower you place the pH the faster it will rise since the lower the pH the more bicarbonate converted into carbonic acid (basically CO2 in water).

Finally borate in conjunction with bicarbonate tend to "lock" the pH around 7.8 - 7.7 for an extended period and I would not try to fight that since you are then fighting the double buffer system (bicarbonate and borate) you have in your water.

Actually, looking at your numbers I would say not to mess with them until they go out of range. They are close to "perfect".

[new2spa]

OK thanks Waterbear, it's much appreciated. I was just worried that my TA being that low would create other problems. I have no idea what those problem would be anyways!

I have a hard time wrapping my head around the TA and pH relationship. Thank you Chem Geek and Waterbear for all the valuable input on this thread. I would have been completely lost.

[chem geek]

I know I am within range of my TA, however I was under the assumption per Nitro's guild to water maintenance that my TA being so low could create an "unstable situation".

Thanks for the min/max info on the ACE® system in your post. As for Nitro's guide, we really need to change that (not sure we can edit another's post) to not recommend 80 ppm except as a maximum. When using any hypochlorite system, be it bleach, lithium hypochlorite, or a saltwater chlorine generator, one wants to have a lower TA, as low as 50 ppm if necessary. With the 50 ppm Borates in the water, things do not get "unstable" with regards to pH. The basic rule is that if the pH tends to rise over time, then the TA should NOT be raised, but if anything, it should be lowered. TA is a SOURCE of rising pH -- it is not only a pH buffer. TA is mostly a measure of bicarbonate so is a measure of the carbonation of the water -- with more carbonation, you get more carbon dioxide outgassing and that causes the pH to rise. So ironically, a higher TA can make the pH LESS stable -- that is, it can make it tend to rise unless you are using a net acidic source of chlorine or other chemicals such as MPS or bromine tabs.

As waterbear wrote, your numbers look good. Don't overthing this and don't sweat it -- except being in the spa purging those toxins from your body as you relax and enjoy...

[waterbear]

OK thanks Waterbear, it's much appreciated. I was just worried that my TA being that low would create other problems. I have no idea what those problem would be anyways!

IF you were using an acidic santizer (as chem geek stated above) then a too low TA could lead to a pH 'crash' since the use of such sanitzers really needs the pH rise created by a higher TA to offset the constant addition acidic substances into the water. This is not your case!

I have a hard time wrapping my head around the TA and pH relationship.

Many people do but it is really easy when you understand what TA is. What we call TA is a bicarbonate buffer system (a buffer is something that tends to resist pH change and keeps the pH at at certain point, bicarbonate tends to keep pH at around 8.2 which is why we do not want it too high!) and it wants to move the pH upward. Period. When we use borate in addition we put in a secondary buffer system that wants to move pH downward so together they tend to stabilize the pH arund 7.6=7.8.

Thank you Chem Geek and Waterbear for all the valuable input on this thread. I would have been completely lost.

Hope this helps. Remeber, this is a spa and the idea is to soak and enjoy, not stress over water that is in range!

[new2spa]

Just wanted to say thanks again guys. My water quality has been stable(knock on wood), and my ACE system is more then keeping up with my CD now. Just wanted to say thanks again for all the help on these forums. Also had 1 last question. On my next refill, would it be better for me to add gentle spa AFTER I get my TA/pH balanced? I added it right out of the gates on this fill.

[chem geek]

Yes, I think it is easier to adjust pH and especially TA before adding the ProTeam Gentle Spa. The reason is that the added borates buffer the pH making the TA lowering process harder to manage in terms of getting the TA lower -- especially for the later steps that try and get the pH back up using aeration alone. As you have found, you can certainly lower the TA via the acid & aeration process even after adding the Gentle Spa, but the movement of pH is slower.

[waterbear]

Yes, I think it is easier to adjust pH and especially TA before adding the ProTeam Gentle Spa. The reason is that the added borates buffer the pH making the TA lowering process harder to manage in terms of getting the TA lower -- especially for the later steps that try and get the pH back up using aeration alone. As you have found, you can certainly lower the TA via the acid & aeration process even after adding the Gentle Spa, but the movement of pH is slower.

What chem geek said.

[new2spa]

I didn't really want to start a new thread to ask this, was hoping Chem or Bear might help me out. I got my tub all dialed in, however my ACE system has me kinda stumped. I soak in my spa for about an hour a day, yet my CD demand is very low, between 2-3ppm of FC chlorine gets used during my hour long soak. I keep turning my ACE system down (lowing USE level), trying to hit the "sweet" spot with my ACE system to produce just enough chlorine. My tub is sitting at 6.5 FC right now. I would like to get it so that it stays around 5 before soaks, that when when I get out it should be somewhere between 2-3FC. Does this sound right to you guys? Can it be possible my CD demand is that low during my soaks?

[waterbear]

I didn't really want to start a new thread to ask this, was hoping Chem or Bear might help me out. I got my tub all dialed in, however my ACE system has me kinda stumped. I soak in my spa for about an hour a day, yet my CD demand is very low, between 2-3ppm of FC chlorine gets used during my hour long soak. I keep turning my ACE system down (lowing USE level), trying to hit the "sweet" spot with my ACE system to produce just enough chlorine. My tub is sitting at 6.5 FC right now. I would like to get it so that it stays around 5 before soaks, that when when I get out it should be somewhere between 2-3FC. Does this sound right to you guys? Can it be possible my CD demand is that low during my soaks?

Yes, it's possible. It can take a bit to get everything adjusted and it is trial and error. Go slow so the system has time to stabilize. Since your system is always adding chlorine you really don't have to worry about how much is used up soaking as long as your FC levels stary in range and fairly stable. Don't overthink it and make yourself crazy. Just enjoy the tub!

BTW, the handle is waterbear, not Bear. If you prefer you can call me tardigrade.

[new2spa]

TYVM Waterbear, I appreciate it. I figured I am over thinking this stuff, I am kinda fanatical about taking care of the things I own.

[chem geek]

If the ACE system is turned up, then it will oxidize bather waste even during your soak (assuming it is running while you are in the spa -- do you know if that is the case?). The chlorine demand during a soak is not the full chlorine demand. Only some of your bather waste reacts with chlorine during the soak while the rest is handled in the hours after your soak. This is why the real chlorine demand test is over a 24-hour period.

So to have a 2-3 ppm FC drop during a one-hour soak seems reasonable even without the ACE since the other 3-4 ppm FC drop would occur in the hours after your soak. So other than your FC level remaining on the high side, it sounds like you are in good shape. You can just continue to lower your ACE on-time until you find that sweet spot that just keeps up with your bather load and background chlorine loss. You should be able to start your soak with something closer to 2 ppm FC which should be less noticeable, but you'd want to make sure that the ACE system turned on at least very soon after your soak (otherwise you'd have to dose manually which I presume you are trying to avoid). Most people don't like soaking with higher chlorine levels so the tradeoff is having fast sanitation throughout the soak vs. smelling more chlorine by-products. Unless you are sharing the tub with others who are sick, the risk is very low since the chlorine level is only low for a relatively short period of time (again, assuming the ACE kicks in or you manually dose). If you don't mind 4-5 ppm FC, then that's fine -- it's a personal choice.

At least you've got some CYA in the water so that the chlorine isn't as strong oxidizing your skin, swimsuit, etc. and outgassing to degrade the hot tub cover. It's unfortunate that the ACE system makes no mention of the use of CYA (or borates, for that matter), but that's what we're here for. Don't forget to let us know if, over months, the CYA level is dropping more than we normally see in spas which is at around 5 ppm per month. The ACE system could be oxidizing some CYA itself and it would be good for us to know that so that we can give appropriate advice to other ACE system users.

[new2spa]

Just did a Full test of my water. My CYA is at around 10 (hard to tell because the test only goes to 30). Is having too little or no CYA a bad thing?

[chem geek]

Having too little CYA will have the active chlorine level stronger than it needs to be. In a hot (104ºF) spa, 5 ppm FC with 10 ppm CYA would have more than twice the active chlorine level compared to 5 ppm FC with 30 ppm CYA (in an 80ºF pool, the difference would be over a factor of 4). This would be noticeable as a faster oxidation of swimsuits, skin and hot tub cover degradation over the long-term. It's not a disaster, but something you can easily address by either adding some pure CYA or using some Dichlor though I realize that your chlorine levels are currently pretty high.

The issue would be more pressing if you were comparing having 30 ppm CYA vs. no CYA where the difference would be over a factor of 6 in a hot 104ºF spa and over a factor of 25 in an 80ºF pool. It is this kind of difference that annoys my wife to no end since swimming in the community center indoor pool with 2 ppm FC and no CYA has over 10 times the active chlorine level of our own outdoor pool at 88ºF. This factor of 10 difference readily shows up in her swimsuits used in the community center pool only lasting for a single season (elasticity gets shot) while they last for many years in our own pool. She also notices a significant difference in the flakiness of her skin and frizziness of her hair.