mscdman

With use 3x a week (15-20 mins each and 35-40 degree temps) on my covered tub it’s looking like about 1/8th-1/4 inch a week now that I’ve marked the water level

Incidentally, are there any hardware or shell or cover problems if the bromine levels are not constant like I have? Meaning it’s 10+ppm when I’m not using it then is low when using then back up 10+? Otherwise rather than adding oxidizer after every use (every other day ish) I’d have to add daily inbetween uses

I’ve been using the 7.5% bleach and not experienced any foam in my bromine spa thus far. Use the bleach to oxidize the bromide.

I’ve got some interesting data/test results I’ll be sharing soon but have been noticing some odd things on my new tub. Background: seeded 15-30pm bromide salts. No floater. Oxidizer. Tub used every other day. Ah sum purged prior to fill ~1 month ago. started adding 2tsp of 1-step (85% dichlor and 15% bromide) after every use. Findings per previous posts and steps were that after use it would raise the bromine to about 10-12ppm. I’d skip a day and when using the day after the skip the bromine was about 4ish when I’d use it. So about an 4ish ppm drop/day. Anyway I continued this way for a few weeks - with CYA being added as a byproduct and after testing CYA for about 3 weeks - CYA in the normal range. This week I’ve switched to bleach 7.5% concentrate. Adding ~3oz (which is oddly more than should be needed per pool calculator) after each use is bringing bromine up to 10-12ppm (as it was with the 2tsp of 1-step) (FYI - I should only be needing 2.1oz of 7.5% bleach to achieve this bromine level- maybe the 1 month of CYA levels is hampering this?) anyway ....here’s the odd thing. When using the 1-step above after the skipped day it was still at 4ppm. Now after switching to bleach with a level of 10-12ppm after use, when coming back after the skipped day the bromine is 0. why would this be different using the 1-step vs bleach? @dlleno@chem geek

Update: I have a nifty excel sheet I’ve been tracking bromine levels and decay. So far it’s looking like about a 4-5ppm per day decay/loss of bromine with no use and around 6-8 ppm drop with a tub use on that day. This is with a CD ozonator and no floater. I currently use the tub every other day so what I’m trying to determine now is what level I need to pump up the bromine to after use so that it’s at 5-6ppm during my use days. If I’m doing my math right I need the levels AFTER use to be 11ppm. Then it should be right at 5-6ppm when I get in the day after the skip day. According to the pool calculator 1.5 tsp of my 82% dichlor/15% bromide mixture for my tub size after use should do it. I may add 2tsp though to be safe after every use. For you cheapos like me this is only $.20 cents of chemicals per use or about $2.50 a month. That’s pretty cheap chemical wise vs bromine tablets if you ask me. In reality it will be cheaper than that because I’m planning to switch to Bleach as soon as CYA levels are in range

Ahh. So you are saying that adding the right amount of MPS shouldn’t skyrocket your bromine levels.

I’m thinking so too. Also Intrrested I seeing the rate if non use decay. Meaning if it’s say 5ppm before use - shock - raise to 10ppm - after a day of non use to see how far it’s dropped

Every site I go on says using a MPS weekly shock allows you to re-enter the tub in up to 10 mins later. How is this possible given the shock instantly oxidizes the bromide ions and raises bromine to way high levels?? It takes days for my bromine levels to drop naturally from a level like 12-15ppm to a safe lower level. How are you able to get in after 10 mins? 🤷🏻‍♂️ what am I missing here that every site seems to know?

To clarify, I’m not “trying” to generate bromine using my CD ozonator. I was just curious if it would. And I’m finding it doesn’t. Which to be honest I’m happy about. I don’t like the idea of not having control over the level of bromine generated. Which is why I’m liking this 2-step bromine using bleach method. I can theoretically generate the exact amount of bromine I need using a specified amount of bleach. Of course that theory is also currently being tested for feasibility in my system. If it doesn’t work I’ll have to go to 3-step but I am optimistic it will

What causes bromine in a 2-step system to dissipate without use? Is it just natural decay of the chemical? Eating away at germs even though tub not in use? I suspect some combo of both.

Oddly mine is a CD ozonator and still per this experiment does not oxidize enough to negate the need for manual shock in my 2-step

Now I have another question though. Does Bromine naturally lessen/go away in the tub (well it’s rhetorical because it is) when not in use? Put another way, if you have say 10ppm bromine in the tub one day, what makes it drop from that level assuming no use, no open, no floater etc?

Update: Stopped the manual shock and used the tub and the bromine levels are indeed dropping even with the ozone running (note I don’t use a floater w tabs - only initial bromide reserve seed). In theory if the ozone was constantly oxidizing the bromine at a HIGH level, the bromine level would be creeping UP not DOWN as I am seeing. So, still testing for a few more days but indications are that if the ozonator was oxidizing the bromide at a HIGH level you’d see increasing levels of bromine without shock being needed. And that doesn’t seem to be the case so far to any noticeable degree. Therefore, I’m theorizing that the ozonator does help with oxidation bromide but not near the level that is needed alone without manual usage shock or a floater. the next step for me is to continue this test and to see if I can manually maintain the bromine level with manual usage (per usage) of bleach - reactivating the bromide reserve without spiking it too high and having to wait to use the tub

I’ll see what happens and report back. Right now PH is too high 8.2. But...I think it’s a false reading due to high bromine levels. So going to let that settle down and retest. I’ve got some experimenting to do!

I’ll stop the manual bleach shock and see what happens and let you know.

And you are adding PH down then?

Thanks! Being net positive then are you finding you have to add PH down regularly to compensate?

Also - @dllenodoes adding the manual bleach after each use to reactivate bromine also raise the PH?

@dllenoWon’t the ozone constantly raise higher and higher the bromine levels though? This seems to be a concern... if you start with a reserve of say 30ppm and don’t use the tub say for a week, isn’t that ozontor raising and raising the bromine levels from bromide? when using bleach to reactivate the bromine you have some “control”. But it seems like the ozone is a free for all of never ending bromine building until you’ve exacerbated the bromide reserve

Still trying to get this water chemistry right and finding my bromine levels are way too high (11ppm). I have an ozonator. I seeded the tub with 30ppm bromide salts. if this ozonator is running isn’t it always oxidizing the bromide thus without any manual shocking after use - won’t the bromine always be high (too high in this case?)? trying to figure out why my bromine is so high. No floater being used. Only the initial seed and ozonator plus occasional manual shock.

I’ve got the GFCI

Are there any electrical shock dangers of using the outdoor tub with GFCI disconnect WHILE snowing? Theres no way for the electricity to arc from the disconnect box through the snowflakes to me in the tub is there? im probably just over reacting.

All I can’t say is I did the test described above with no use and there was no droppage so Im guessing it can’t be due to a leak so I don’t see what else it could be other than evaporation and carry out loss. We have low low humidity here and cold temps.

Interesting. So with an ozone system I’ll need to add more sodium bromide to keep up?

I’m trying to see how the following regarding an ozoneator (which I have) depletes the bromide reserve. I’m no scientist but wondering if this could be my issue and if so how the O3 is doing that.. ” A 2-step system with an efficient ozonator might be able to achieve the constant bromine level without the use of, or by using less oxidizer (MPS or chlorine) since the ozone is constantly oxidizing the sodium bromide while it is on. However, the ozone may also deplete the bromide reserve more quickly, leading to the use of more sodium bromide, or a shorter time between necessary drain and refills. Also, ozone can cause bromates to form in your water.”