I shock my spa 1x/week w/ 10% bleach. I have a 300 gal. AG Aquaterra spa. Based on my calculations, I use 115 ml. In the warm months like now, I am keeping the water at 100 degrees. The problem I hate with shocking is that it raises the bromine level crazy high and renders the spa unusable for days. I try to burn it off by uncovering it and turning on the jets (without the aeration though; not sure if it would be better to add turn on the jet aeration to lower the bromine). Additionally, I remove the bromine floater (I use teh 3 step bromine system). It just doesn't seem to help get it lower than 10 at least for a couple of days. Sure, the jets are not on continuously. They just run for 15 min. cycles on high, then shift to low for 15 min. So, I have to keep going out to turn them back on.
The instructions in the 3 step bromine state to not use the spa until the bromine level is <10. I tried to research why and is it okay/safe to use w/ a high bromine level, but I could not find any posts about this. Before I had started managing it myself, at one time the level was crazy high and the pool guy said "don't worry it will just dry you out a little." Well, I did use it that time and yes, it definitely did dry out my skin, a lot. So, is that the only thing I risk using it w/ s high bromine level? For reference, I use a TF100 kit. I test the bromine in the spa w/ the OTO test. I just go off of what I have read here that a darker yellow is >10+ bromine, maybe up to 20. The color last night when I wanted to use it but didn't was a semi-dark yellow.
Lastly, I am not sure if I was reading this correctly, but I could have sworn I read a post in which Chem Geek had responded to someone that the FAS-DPD test could be used for bromine, but you must multiply by 2.25. Is that correct? For example, let's say the FAS-DPD used 10 drops, so that is 5 (10 * 0.5). Then 5 * 2.25 = 11.25. Could this test actually be used that way for bromine?
Tx for all the help.