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The Bromine Schedule

How to convert and sanitise your swimming pool with bromine.
These are quick instructions. For further details, click on the links or see the glossary below.

PLEASE NOTE - All dosages given are for 50,000 litre pools. For other sizes simply pro rata the dosage. The objective to to establish and maintain a bromine bank of at least 80 ppm.
Anything up to 1,000 ppm is acceptable with cost being the only consideration.
Less than 25 ppm - it simply will not work. So better the err on on high side.

VERY IMPORTANT: Some types of pH test (Phenol Red) do not work properly with bromide and serious errors could occur if this is not correctly understood.

STARTING OUT - with new water or converting an existing pool to Bromine the Bromine Bank has to be  establish. It is always best to do this early in the year, when the water is cool and not a lot of bathing going on. For some reason, that I have not been able to establish, there is always a high oxidant (chlorine or monopersulphate) demand when the bromine bank is first established or increased.
The process is as follows -

1. Check the total alkalinity and balance the water.
2. Hoover and backwash thoroughly.
3. Add 4.0 Kgs Bromine Salt (Sodium Bromide) into the skimmer, with the filter running on "Circulation" and wait 10 minutes for it to disperse throughout the pool.
4. Shock to 12 ppm. Best with liquid chlorine (Sodium Hypochlorite).
5. After 24 hours: Test for Total Bromine with a DPD test kit. If this is less than 4 (2 on the Chlorine scale) then shock again and continue shocking until you get a result.
6. Maintain the pool in the normal way by adding oxidants (chlorine product or monopersulphate) to achieve the required sanitizer level, pH and total alkalinity but monitor the pool every 2/3 days until it has settled down.
If the sanitizer should disappear then shock again. Don't waste money on trichlor or monopersulphate, liquid chlorine is much cheaper.

Thereafter you only need to maintain the bromine bank annually and add sufficient sodium bromine to make up for water loss. This is a lot less than you would think because evaporation does not count as water loss - only backwashing and splashing out. As long as the pool does not leak then this is only around 25%.
There is no test for bromine bank outside of a labaratory. However, best not to worry, you either have a leak (in which case it is best to start over every spring), or you don't have a leak and it is safe to assume 25% water loss.

EARLY SPRING (March/April) - Maintain the Bromine Bank exactly as above but just add 2.0 Kgs of  Sodium Bromide.

REGULAR VISITS THROUGHOUT THE YEAR

The frequency of these visits obviously varies but should not be less than every 14 days from November to April and at least every week during the Summer or whilst the pool is in use.

1. Adjust the Free Bromine Level.

2. Check and adjust the pH to 7.6 to 8.0. If large variances are noticed then check and adjust the total alkalinity.

3. Observe the water quality and shock if necessary. Shocking is only likely to be necessary if there has been exceptional bather lead, bather abuse or a fault with the purification plant.

This at is really all you need to do! More details of the different tasks are provided in the glossary below.

BROMINE GLOSSARY

Bromine Bank: The amount of Bromine Ion that is available in the water. This is introduced by adding Bromine Salt (Sodium Bromide) to the water to provide at least 80 ppm. There is no upper limit.

Bromine Chemistry: When chlorine is added to water in any form (gas, liquid or solid) Hypochlorous Acid is formed - this is the chlorine sanitizer. If sufficient Bromine Ion is present then Hypobromous Acid is formed - this is the bromine sanitizer. The chlorine disappears from the water after oxidising the bromine.
Bromine can also be oxidised with monopersulphate ot hydrogen peroxide.
When the bromine sanitizer has done its work the Bromine Ion returns to the water for re-use.

Bromamines: Bromine sanitizer reacts with bather waste to form bromamines. These are as good a sanitizer as the bromine itself. They have hardly any odour and have no harmful effect on eyes or skin.

Chloromines: Chlorine sanitizer reacts with bather waste to form cloramines, which are undesirable in pool water because they cause stinging eyes and skin and an unpleasant chlorine odour.
Chloramines should be removed by shocking as soon as more than 0.05 ppm have formed.

Phenol Red: A chemical used to test the pH of pool water. The colour changes from strong yellow (pH 6.8 - Acidic), through shades of orange to strong pink (pH 8.2 Basic). The actual pH is read off against a colour comparator supplied with the test kit.
Phenol red is affected by bromine sanitizer and shows a purple/brown colour, making the test colour completely false. The real danger however is that, if the tester is unaware of this, the test could be interpreted as very high pH when it is in fact very low. Thereafter the addition of pH-minus chemicals could have disastrous consequences.
There are various solutions: Some test kits are specially prepared for this or 2 drops of
sodium thiosulfate can be added to the test water prior to the addition of the phenol red.
Whenever a pH anomaly is noticed, the best practice is always to do Total Alkalinity test before adding chemical to adjust the pH.

Total Alkalinity and Water Balancing - Correct water balancing is a "trade off" between Calcium Hardness, Total Alkalinity and pH. A perfect, but rather complicated, test of properly balanced water is provided by using the Langlier Index but there is little need to resort to this unless a serious anomaly is noticed.
The whole objective is to achieve a water balance that is neither acidic (corrosive) not heavily scale-forming and with a stable pH within the recommended range which, in the case of Bromine can be between 7.6 and 8.0.
Costa Blanca water generally has Calcium Hardness within the correct range. This can be ignored as long as there is no serious anomaly. However it should be noted that there would be a real problem if the pool is filled via a water softener as these remove all dissolved calcium and it has to be put back.
Which leaves us with just total alkalinity and pH with the latter being the dominating factor.
Certain facts should be taken into account whilst trying to determine the suitable pH -

a) Costa Blanca water generally has a high TA (around 180).
b) TriChlor (tablets and granules) are acids and cause the TA to reduce. Consequently, during warm weather and heavy use the TA will fall. Over a whole year there would probably be a gradually drift downwards.
c) The recommended TA is between 80 and 120. However cyanuric acid distorts the test and 30% of the CYA has to be deducted from the actual test reading. With high CYA (say) 300 ppm a proper TA balance becomes impossible because this would mean 170 to 210, which could result in a pH of well over 8.2.
Therefore we have the trade-off between TA and pH and the optimum TA is the level at which the pH is stable within the correct range.

Adjusting the pH/TA - is just a question of understanding the different pH-plus and pH-minus chemicals.
I recommend using the Taylor test kit because this comes with charts for product amounts for different size pools.

To lower the pH with little affect on the TA: Trickle Sulfumant (Muratic Acid) very slowly in the return-jet stream so that the product is slowly dissipated throughout the pool.
To lower the pH and the TA: Pour the Sulfumant slowly into a single column in the deep end with the pump off and wait 30 minutes before starting it up.
To raise the pH with little affect to the TA: Use Soda Ash (Sodium Carbonate).
To raise the pH and the TA: Use Baking Soda (Sodium Carbonate).

For general, practical purposes you should never need Carbonate in Costa Blanca and slight adjustments to the pH with Bicarbonate will usually take care of the TA as well over long periods.

High pH with low TA, usually also turbid (or even green) water. A real head-banger to deal with? Not really, you probably just have a lot of alkaline debris, which can easily happen if there has been bather abuse or neglect.
The low TA is the real indicator. Get the bathers out of the water and do a heavy shock before anything, you would probably find that the pH falls dramatically and then you'll know exactly what to do.
NB: If the pH is around, or over 8.0 a chlorine shock will have little effect so the have to get that down, before you add the shock, and adjust the TA after the water clean-up.

Cyanuric Acid: When TriChlor is dissolved in water Hypochlorous Acid and Cyanuric Acid (CNOH)3 are produced. The Cyanuric Acid (CYA) acts as a stabiliser and, without the CYA, the chlorine would disappear quickly from the water, especially in strong sunlight - but a real problem can occur if there is too much!
What happens is that “normal” chlorine levels cease to work properly, more and more TriChlor is required (adding more and more CYA) until there is so much that the chlorine "locks-up" completely.
The correct way to use TriChlor means regular shocking with liquid chlorine or monopersulphate (neither contain CYA) and by draining part of the water each year to keep the level between 30 and 50 ppm.
The real problem here is that water is expensive as well as the extra visits required by a professional pool technician. Bromine is not affected by CYA.