Ultraman Posted August 14, 2019 Report Share Posted August 14, 2019 Help! I've got some very peculiar things happening and have tried researching all over the net and tried many approaches but can't seem to figure out what's happening. I'm hoping with this forum of more in the know people, perhaps I can figure this thing out. After refilling a 500 gallon (1600 litre) spa and balancing (TA = 80, PH = 7.5, CH = 150), I added 4 tbs Bromine Granules and got a reading about 3ppm. The next day, my 2 kids and I used the spa for about 2 hours. The third day, I shocked with Spa Magic (potassium persulfate, sodium bisulphate, ammonium chloride, aluminium sulphate, sodium borate) according what the bottle says 150g (10 tbs) Then I have this very odd thing happen with my ColorQ Pro 7 test kit. When testing with DPD 1A and 1B (test for Chlorine and Bromine), it starts off with a very low reading 0.1 for FCL and 0.2 for Br, then after about 3 mins, the reading jumps to 3.5 ppm for FCL and 8 ppm for Br. If I wait till 10 min. the final reading is 6.5 ppm FCL and 14 ppm for Br. It stays that reading steady after 10 mins. The kids and I enjoyed the spa for the next 3 days without shocking as I thought we had enough Bromine. Then my kids and I came down with Hot Tub bacterial infection spots on the 3rd day of using the tub. I read online and in the Pro 7 test kit that MPS might interfere with CCL reading making them very high and that CCL may affect FCL/Br reading if the test is done after 30 sec. giving false high readings when actually the FCL/Br was low. So I tried to shock by superclorination using the Bromine Granules as it says on the bottle. I put 40 grams (2.5 tbs) and measured after about 1 hour and got a reading of 1.5 FCL and 3 ppm Br immediately, but again rising to 14.0 ppm Br after 10 mins. I convinced myself to ignore any reading after 30 sec. as interference. Next day, FCL and Br were back down to 0.1 and 0.3 respectively, so I shocked again with 40 grams (2.5 tbs) of Bromine Granules. I tested today and again get 0.1 and 0.3 respectively, rising to 14 ppm after 10 mins. I don't know how this Br bank works, but I can't seem to get any Bromine level after 2 days of 5 tbs of Bromine Granules! I'm not sure if I should continue to put more and more Bromine Granules in, shock with Spa Magic or what reading to trust as the DPD 1A/B changes over time! So frustrated, hope someone can help as I've research this thing forever... Help! Quote Link to comment Share on other sites More sharing options...
Ultraman Posted August 14, 2019 Author Report Share Posted August 14, 2019 Btw, the test strip also shows zero Br ppm. So I took a water sample to the Spa shop and they tested with their machine and said I have low Br of 0.4 and advise me to add more Br. I asked them to test using their machine again after 10 min. and they got a reading of 14 ppm! I asked them why it is changing and they were clueless, saying they have never encountered this before. Back to square one lost in confusion... Quote Link to comment Share on other sites More sharing options...
Ultraman Posted August 14, 2019 Author Report Share Posted August 14, 2019 Ok, called Lamotte who makes the ColorQ Pro test kit and they confirmed that I should be taking the reading before 30 seconds as after that, secondary reactions with oxygen, etc. are happening which may cause the chemical reaction to continue with the reagent causing false readings. So it looks like I have low Br. I will try to shock with Bleach to see if I can get the Br reading to go up, otherwise, I'll have to keep adding EZ Brom (Sodium Dichlor & Sodium Bromide) to see if that gets the Br reading to go up. Quote Link to comment Share on other sites More sharing options...
Ultraman Posted August 16, 2019 Author Report Share Posted August 16, 2019 Ok, finally got a high reading on Br (11). I think the situation of the low reading was I was adding Br/DiClor, then opening the cover and turning on the jets for 30 min or so. I read somewhere else that Bromine would burn off in 30 min with sunshine and cover off. So today was overcast, I added 40 gr (2.5 tbs) and turned on the jets for 20 min, but kept the cover closed. I tested about 3 hours later and got a high Br. reading. So me thinks it was leaving the cover off in the sunlight for 1 hour with the jets on last time I added 40 gr. Br/DiClor. Of course, it could also just be I have now burned off all of the heavy organics built up over the past week and reached the tipping point (Bromine Bank?). Well, I dunno, just keep monitoring to see if I can get it stable at 2-6 ppm for a week. Quote Link to comment Share on other sites More sharing options...
Ultraman Posted August 16, 2019 Author Report Share Posted August 16, 2019 Btw, prior to adding Br/DiChlor, I experimented by adding 1 cup Bleach to shock/reactivate the Bromine as was mentioned in other posts. After 3 hours, the Br reading was still zero so that didn't work... Quote Link to comment Share on other sites More sharing options...
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