My Initial Chlorine Demand

[tjbrew]

Several posts back (can't seem to locate it) Nitro talked about chlorine demand and how it would be interesting to know what people's initial chlorine demand is. I just refilled last weekend and have some data.

I refilled with mostly unsoftened well water and balanced my water with acid/aeration.

Then I installed the Nature2 cartridge and shocked with the amount specified by the Nature2 instructions to activate the cartridge.

Question: What needs "activating"? Are there no silver or copper ions released unless there is an initial dichlor presence?

My initial fc was 8ppm.

After 24 hours it was down to 2ppm.

If I remember correctly, Nitro mentioned his initial CD was 25%, while mine was a whopping 75%.

I wonder if this has anything to do with burning off contaminants in the Nature2 cartridge?

Or possibly the fact that I used unchlorinated well water? The water did have a slight "earthy" smell.

That night (at fc=2ppm) we soaked for 30 minutes and I added another approx fc=4ppm (1tbsp dichlor).

After another 24 hours the reading was fc=4ppm, which would indicate a lower chlorine demand of 33%, though I probably have to account for the 2 person, 30 minute bather waste. That night we soaked with 1 tbsp MPS added beforehand.

No chlorine was added since the level started at 4ppm.

The next night the fc=1ppm and we did not soak. I can't find what the rule of thumb is for chlorine use per bather hour, so

I'm not sure what my CD is at this step. Plus the MPS addition probably messes up the calculation for this night anyway.

I added about 2.5ppm fc just to bump it up.

Tonight the reading is 2.5ppm and I'm going for a soak in a few minutes! This looks like a nice low CD of 28%

Anyway, the water is clearer and better feeling than ever before thanks to all I've learned from Nitro and Chemgeek!

I think the Gentle Spa was definitely worth it. My ph has been rock solid at 7.6 since I refilled, and I use a lot of aeration during soaks.

[tjbrew]

Ok, so that was a really boring post since noone replied.

I'm not sure why I'm replying to my own post, but there is an interesting (?) followup.

I rotated my filters a week after my refill and ... OMG! They are dirty! Light brown and sandy

colored. I guess that would explain my 75% initial CD. There must be a lot of sediment that

gets pulled up from the bottom of my well.

Do any of you with city water experience dirty filters on refill? I'm thinking not.

I will try harder next time to use softened water in the hopes that the softener membrane

filters out some of the dirt! I also used a pre-filter on the end of the hose, but apparently it

is only working on coarser particles (or not at all).

After a week it seems like my CD has settled in to about 50%.

[chem geek]

A dirty filter will increase chlorine demand if what is caught in the filter is something that chlorine reacts with. So if there are nitrogenous organics, then that can react with chlorine. Only some minerals will react with chlorine -- for example, ferrous ions can get oxidized to ferric ions and metal itself (i.e. iron or copper) can get oxidized by chlorine. Perhaps that is what is going on in your situation.

[Nitro]

I must have missed this post. Interesting information though.

I figure everybody's Initial CD will be different, depending on the water source. That's why I recommend testing your Initial CD first. Although I think after a few weeks your CD will settle down, becuase anything in the source water (metals etc.) will have been oxidized, and the only thing left will be bather waste.

CD is relative, and is meant to be compared to your own readings. Just keep it as low as you can, and don't let it keep rising. If it goes much above 50%, then you know something is wrong. (i.e. in your case dirty filter).

Keep us updated.

[Kapp]

I must have missed this post. Interesting information though.

I figure everybody's Initial CD will be different, depending on the water source. That's why I recommend testing your Initial CD first. Although I think after a few weeks your CD will settle down, becuase anything in the source water (metals etc.) will have been oxidized, and the only thing left will be bather waste.

CD is relative, and is meant to be compared to your own readings. Just keep it as low as you can, and don't let it keep rising. If it goes much above 50%, then you know something is wrong. (i.e. in your case dirty filter).

Keep us updated.

Interestingly, I just caught your inital post after adding a similar question to the end of my screeching circ pump question...(See screeching circ pump in Portable spas) anyway, I also switched over to Nature2 and was wondering the same thing about getting the chlorine up and stable. I see from the last comment from Nitro that it might take a few weeks to stablize. Who knows what the heck is this Belgian water! I am a total newby learing all this stuff from you guys like a sponge. Doing some research It seemed to me that switching to the nature2 cartridge would reduce the amount of chlorine needed only needing to show 1-3ppm on the strip. I am not getting it to read any after adding about 1 1/2 tbsp 3 times now after the refill. I also couldn't find any directions/suggestions about how much MPS (Zodiac Cense) to use initially or anything about needing a certain dose to "activate" the cartridge. I just tested using the Nature2 strips that show MPS for the first time today and it showed dead on good. I also read about two ways to use the chlorine granules and MPS. 1) use just a 1/2tbps before each use and chlorine weekly for shock and 2) just the opposite except add a small amount of chlorine granules (1/2 tbps) AFTER each use then MPS as a weekly shock (how much I don't know either. I really like the idea of using the small amount of MPS prior to bathing as it smells so good and that is what I have tried the last two days. (Normal Bather use is 1 person daily or every other day for 30 mins in a 345 gallons spa). I am hoping this gets easier...thanks for your input and help...Kapp

[tjbrew]

I must have missed this post. Interesting information though.

I figure everybody's Initial CD will be different, depending on the water source. That's why I recommend testing your Initial CD first. Although I think after a few weeks your CD will settle down, becuase anything in the source water (metals etc.) will have been oxidized, and the only thing left will be bather waste.

CD is relative, and is meant to be compared to your own readings. Just keep it as low as you can, and don't let it keep rising. If it goes much above 50%, then you know something is wrong. (i.e. in your case dirty filter).

Keep us updated.

Interestingly, I just caught your inital post after adding a similar question to the end of my screeching circ pump question...(See screeching circ pump in Portable spas) anyway, I also switched over to Nature2 and was wondering the same thing about getting the chlorine up and stable. I see from the last comment from Nitro that it might take a few weeks to stablize. Who knows what the heck is this Belgian water! I am a total newby learing all this stuff from you guys like a sponge. Doing some research It seemed to me that switching to the nature2 cartridge would reduce the amount of chlorine needed only needing to show 1-3ppm on the strip. I am not getting it to read any after adding about 1 1/2 tbsp 3 times now after the refill. I also couldn't find any directions/suggestions about how much MPS (Zodiac Cense) to use initially or anything about needing a certain dose to "activate" the cartridge. I just tested using the Nature2 strips that show MPS for the first time today and it showed dead on good. I also read about two ways to use the chlorine granules and MPS. 1) use just a 1/2tbps before each use and chlorine weekly for shock and 2) just the opposite except add a small amount of chlorine granules (1/2 tbps) AFTER each use then MPS as a weekly shock (how much I don't know either. I really like the idea of using the small amount of MPS prior to bathing as it smells so good and that is what I have tried the last two days. (Normal Bather use is 1 person daily or every other day for 30 mins in a 345 gallons spa). I am hoping this gets easier...thanks for your input and help...Kapp

Wow! Brussels, Belgium! One of my favorite places ... for beer! I'd love to have a beer a A La Becasse or A La Mort Subite or many, many other places!

Kapp, in the Nature2 instructions it says you must activate the cartridge with 2tbsp dichlor upon refill. I don't think MPS works the same. I imagine your initial chlorine demand was pretty high for a few days while burning off impurities in the water and cartridge. Plus I think your initial shock level was a little low. I don't bother with the MPS until I get the chlorine situation settled down. I think strips are worthless below 3ppm. Mine don't read anything, but when I use my drop test kit I might read 2ppm. I suggest buying the Taylor or TFT kit. You won't regret it. Cheers, tj

[Kapp]

I must have missed this post. Interesting information though.

I figure everybody's Initial CD will be different, depending on the water source. That's why I recommend testing your Initial CD first. Although I think after a few weeks your CD will settle down, becuase anything in the source water (metals etc.) will have been oxidized, and the only thing left will be bather waste.

CD is relative, and is meant to be compared to your own readings. Just keep it as low as you can, and don't let it keep rising. If it goes much above 50%, then you know something is wrong. (i.e. in your case dirty filter).

Keep us updated.

Interestingly, I just caught your inital post after adding a similar question to the end of my screeching circ pump question...(See screeching circ pump in Portable spas) anyway, I also switched over to Nature2 and was wondering the same thing about getting the chlorine up and stable. I see from the last comment from Nitro that it might take a few weeks to stablize. Who knows what the heck is this Belgian water! I am a total newby learing all this stuff from you guys like a sponge. Doing some research It seemed to me that switching to the nature2 cartridge would reduce the amount of chlorine needed only needing to show 1-3ppm on the strip. I am not getting it to read any after adding about 1 1/2 tbsp 3 times now after the refill. I also couldn't find any directions/suggestions about how much MPS (Zodiac Cense) to use initially or anything about needing a certain dose to "activate" the cartridge. I just tested using the Nature2 strips that show MPS for the first time today and it showed dead on good. I also read about two ways to use the chlorine granules and MPS. 1) use just a 1/2tbps before each use and chlorine weekly for shock and 2) just the opposite except add a small amount of chlorine granules (1/2 tbps) AFTER each use then MPS as a weekly shock (how much I don't know either. I really like the idea of using the small amount of MPS prior to bathing as it smells so good and that is what I have tried the last two days. (Normal Bather use is 1 person daily or every other day for 30 mins in a 345 gallons spa). I am hoping this gets easier...thanks for your input and help...Kapp

Wow! Brussels, Belgium! One of my favorite places ... for beer! I'd love to have a beer a A La Becasse or A La Mort Subite or many, many other places!

Kapp, in the Nature2 instructions it says you must activate the cartridge with 2tbsp dichlor upon refill. I don't think MPS works the same. I imagine your initial chlorine demand was pretty high for a few days while burning off impurities in the water and cartridge. Plus I think your initial shock level was a little low. I don't bother with the MPS until I get the chlorine situation settled down. I think strips are worthless below 3ppm. Mine don't read anything, but when I use my drop test kit I might read 2ppm. I suggest buying the Taylor or TFT kit. You won't regret it. Cheers, tj

587 different kinds of beer (at last count) and all good in the Grand Platz...anyway...I am getting close 4 days after the refill, the chlorine showed sligthly on the stips (I think I will get the test kit thanks) I have been having to add spa down each day to get the PH and ALK down but it is coming down. I seem to remember having to this for awhile the first time I filled it and then the PH, ALK and Calcium levels were literaly perfect for the 4 months I was using that water. Once I get the chlorine level nailed down I will start tracking the MPS. Most suggest I throw a small amount of Zodiac Cense (say 1/2 Tblsp) before each use (a couple mins OK then jump in???) and then use 2 TBLSP of it for the weekly shock. Use the cholorine granules only once in awhile (every couple of weeks or after heavy use or party) does that sound right? I have the Artesian Quail Ridge and most all Artesians have the filter bay with 3 filters, the dealer told me to just float the Nature2 stick in the bay there instead of inserting it in one of the filters. Said it works better, gets all three filters and all the water goes through there anyway, and easier to look at to see if needs replacing. thanks Kapp of SHAPE

[tjbrew]

587 different kinds of beer (at last count) and all good in the Grand Platz...anyway...I am getting close 4 days after the refill, the chlorine showed sligthly on the stips (I think I will get the test kit thanks) I have been having to add spa down each day to get the PH and ALK down but it is coming down. I seem to remember having to this for awhile the first time I filled it and then the PH, ALK and Calcium levels were literaly perfect for the 4 months I was using that water. Once I get the chlorine level nailed down I will start tracking the MPS. Most suggest I throw a small amount of Zodiac Cense (say 1/2 Tblsp) before each use (a couple mins OK then jump in???) and then use 2 TBLSP of it for the weekly shock. Use the cholorine granules only once in awhile (every couple of weeks or after heavy use or party) does that sound right? I have the Artesian Quail Ridge and most all Artesians have the filter bay with 3 filters, the dealer told me to just float the Nature2 stick in the bay there instead of inserting it in one of the filters. Said it works better, gets all three filters and all the water goes through there anyway, and easier to look at to see if needs replacing. thanks Kapp of SHAPE

The test kit will help you dial in your ph and alk levels, which you are supposed to do BEFORE you put the nature2 cartridge in. Use the acid/aeration method that Nitro describes in detail in another post (sorry, I don't have the link). Putting the MPS in right before a soak is ok as long as you're not sensitive to it. My wife seems to be somewhat sensitive to MPS, so I put it in and circulate about 30 minutes to an hour before we go in (I also turn up the heat to 101 at this time, from a resting temp of 97). Often there is plenty of residual MPS from the last time I added it. I use the Aquacheck strips that measure MPS levels. Your MPS usage will be much higher if you have periods of no chlorine.

Adding chlorine only once every two weeks is asking for trouble. I think Nature2 is a LOW chlorine method, not NO chlorine. I try to keep a low residual. If my drop test shows any yellow color it's fine with me. I just tested tonight and the drop test shows about 1ppm fc but when I use a test strip I can't see any residual (I compared it to a test strip using my tap water, which has no chlorine). Maybe I just have crappy chlorine strips (Aquacheck).

Floating the Nature2 cartridge in the filter bay doesn't sound right to me either. I think the reason they want you to put it inside the filter is so that you get a consistent, positive flow across the cartridge that releases the silver ions at a relatively constant rate. The water around the filters in the filter bay is kind of "dead space". When I've changed my filters, a few times I found that while the spa water was clear the "dead space" water in the filter bay was kind of murky. That's a sign the filters need cleaning, I think. I just change mine out with a spare set every week and soak the "dirty" ones.

Happy soaking

[Kapp]

Our Artesian Spa has 3 big filters in the bay the middle one I believe is for the 24 hour circ pump so if i insert the cartridge (Nature2) rather then float in the bay which one of the outside two filters should it go in or does it matter?

I think you are right about the "low chlorine" along with Nature2 so will go more often like once a week and see if I can get it to show up with that much and using the test kit.

Finally, when you said you "circulate" your small amount of MPS prior to soaking for 30 mins do you mean you have to have the jets on or will the 24 hour circ pump that is running suffice to spread it out and absorb? Thanks Kapp

[tjbrew]

Our Artesian Spa has 3 big filters in the bay the middle one I believe is for the 24 hour circ pump so if i insert the cartridge (Nature2) rather then float in the bay which one of the outside two filters should it go in or does it matter?

I think you are right about the "low chlorine" along with Nature2 so will go more often like once a week and see if I can get it to show up with that much and using the test kit.

Finally, when you said you "circulate" your small amount of MPS prior to soaking for 30 mins do you mean you have to have the jets on or will the 24 hour circ pump that is running suffice to spread it out and absorb? Thanks Kapp

I don't think it matters which filter you insert the N2 cartridge in. You just want to have flow across it. I have two cartridges in mine and was never told to use one versus the other. I always run both pumps (jets) whenever I want to thoroughly mix in MPS.

And finally, in my opinion you should add chlorine more often than once per week ... just spread out the amount so there is always a little residual. The only to know how much to add is to monitor the chlorine levels carefully for a few weeks until you get the idea of how much to use to keep the level above zero.