How fast should bromine dissolve

[Jostudly]

I use bromine pucks in my hot tub. Just did a water test and bromine was down to 0.9 so I had some broken pucks and crushed it into powder. I added 2 tablespoons to the tub and ran the jets for 20 mins. After I can still see the powder at the bottom of the tub. How long does it take for it to dissolve. I want to use the tub tonight but not sure if it is safe until the bromine dissolves.  I normally use a floater and u know the pucks last close to a week.

[silverbullet]

Get some Bromine Concentrate for this situation & add a tsp (or whatever it takes) to your filter while on your clean cycle it will dissolve right away.

I only use my floater when I know my tub is not going to be used for a few days. Otherwise I control my water with bromine concentrate. I usually add one tsp per person after each soak. The days I don't use the tub I still add some.

I've found that this works best for me with my water control.

[Jostudly]

Isn't bromine concentrate the same as crushing the pucks? Also why do you put the concentrate into the filter? I added 2 tablespoons not teaspoons as per my dealer because my bromine was below 1.

[Hottubguy]

Isn't bromine concentrate the same as crushing the pucks? Also why do you put the concentrate into the filter? I added 2 tablespoons not teaspoons as per my dealer because my bromine was below 1.

No it's not the same. Granular bromine is a mix of sodium dichloro mixed with sodium bromide whereas tablets are usually 98% bromochloro. The kind we sell has 65% available bromine and 30% available chlorine

[Jostudly]

I have enough of the pucks to last a year. Wonder if I could control my bromine levels from dropping as much if I was to use the concentrate each time I use the tub vs the floater with pucks?

[Hottubguy]

Are you using a shock once a week?  Sodium bromide or a oxy shock?

[Jostudly]

I have a oxidizer non chlorine shock that I use only on high bather load or when my bromine is low. Sometimes I skip the shock and just add more bromine.

[hottubdan]

Shock weekly. It recharges the bromine.

[Jostudly]

If my bromine levels are high wouldn't shocking raise it higher?

[BullFrogSpasMN]

If my bromine levels are high wouldn't shocking raise it higher?

This is from "In the Swim Blog" and does a good job explaining 'Shock' in simple terms....happy tubbing!


There are only four valid reasons for shocking your spa or hot tub. It’s not necessary to shock the spa every time you use it, and maybe not even weekly. Shock your spa for these four reasons:

    To remove bromamines or chloramines in the spa. Using a DPD test kit, you can test for the level of combined chlorine or bromine. Adding an oxidizer in the amount equal to 10x the level of combined sanitizer will break apart these bonds.
   
To remove organic contaminants in the spa. When 3 or 4 users jump into a hot spa, the level of contaminants spikes to a level many times higher than your sanitizer can manage. Adding an oxidizer afterwards will restore sanitary spa water.
   
To reactivate bromides in your spa water. For a bromine spa, using an oxidizer weekly helps to maintain a consistent bromine bank in your spa water. Activating bromine ions with spa shock converts them to hypobromous acid, the killing form of bromine.
   
To Kill bacteria. Remember that non-chlorine shock is not classified as a disinfectant, like chlorine or bromine, but is useful only as an oxidizer. Use chlorine spa shock to kill bacteria and pathogens

[Jostudly]

I also have chlorine shock as well. I know I can add this when my bromine is low to kill bacteria but I am still uncertain when I should just add more bromine to my floater when it is below 3 ppm, or shock with oxidizer or add the chlorine shock?

[Dr. Spa™ Ret.]

When bromine is added to a spa it's in the form of bromide ions. It then activated with an oxidizer to form hypobromous acid. Hypobromous acid is the killing form of bromine. When hypobromous acid reacts with an organic contaminant it's reduced back to bromide ions. The bromide ions can then be reactivated back into hypobromous acid by the addition of an oxidizer. This is somewhat of a continuos cycle with bromine sanitized spas.

If 100 percent of the bromide ions became hypobromous acid and 100 percent of the hypobromous acid returned to bromide ions, you would never again have to add more bromide salt. But hypobromous acid can react with certain chemicals in the water that tie up the bromide ions and prevents them from becoming free bromide ions in the water. This happens when hypobromous acid produces bromate or bromoform for instance. There are many other combinations that tie up the bromine so it can not become a free bromide ions. For this reason more bromine salt or bromide ions need to periodically be added. The level of bromide ions should not go below 15 ppm.

The basis behind 2-part liquid bromine sanitizing systems is to add a salt of bromine (sodium bromide) to the water to get bromide ions and then oxidize the bromide ions with an oxidizer such as monopersulfate (MPS), hydrogen peroxide, percarbonate, ozone or any compound of chlorine to produce hypobromous acid. You need a minimum of 15 ppm of bromide ions for an oxidizer to work and to provide a "bank" of bromide ions for an oxidizer to react with.

Bromine tablets are typically 1-bromo-3-chloro-5,5-dimethylhydantoin. When added to water they hydrolyze to become hypobromous acid. With bromine tablets a separate oxidizer is not necessary to make hypobromous acid, it is already an ingredient in the tablets. When the hypobromous acid reacts with a contaminant and is reduced, it becomes a bromide ion. You then get a build up of bromide ions in the water. After a while, you could just start adding an oxidizer to reactivate the bromide ions to hypobromous acid, but most people don't, they just add more bromine tabs.

Currently is no way to test water to find out how much bromide ions are in it. This is because the same test that measures bromide ions also measures chloride ions and all water has chloride ions in it. Other than making an educated guess, there's no way to tell when the bromide ion level is too low. The 2-part bromine manufacturers know this and recommend that you add some bromide ions (liquid bromide salts) every few weeks or so.

Realistically, a bromine sanitized spa can not be switched over to chlorine, if there's still bromine in the water. All the chlorine added to the water is going to convert bromide ions into hypobromous acid. As long as there's 15 ppm or more of bromide ions in the water, all the chlorine added is going towards converting bromide ions into hypobromous acid, none of it will provide a chlorine residual. The spa will continue to be bromine sanitized until the bromide level gets below 15 ppm. But there is no test kit for measuring just bromide ions in the water and therefore no way to know when the bromide level is below 15 ppm. It could take a week. It could take 2 months.

[Jostudly]

Okay this still did not answer my question from my last post.

[Hottubguy]

Are you testing both free bromine and total bromine or just total Bromine?  Shocking will raise it to high if the free bromine is already high.  If the total Bromine is say 10ppm and the free is 1-2 ppm then you need to shock if they are both at 5 or so then you don't need too

[Jostudly]

I get my water tested by the dealer so it just tests for total bromine. This is why I find it confusing if I should add more bromine pucks or shock.