Vinny,
Your claim that ozone is not scientifically proven to be an effective sanitizer (tell me that I misunderstood you) is not correct at all. Ozone in fact is the most effective of all sanitizers, which is quite definitely a proven fact. I think the confusion might be that although ozone is a proven sanitizer, the use of ozonators has not been substantially proven to be effective. The problem is not with ozone, but with the fact that the ozonators on the market only can generate a very small quantity of ozone and it is very difficult to get it dissolved in the water.
An ozonator is a nice thing to have, but it may or may not kill a lot of bacteria in a spa. It certainly must help, but it is not enough by itself. This information comes from the manufacturers of ozonators.
For the person who asked how much dichlor to use, the answer is 1-3 ppm, which should be measured approximately 10 to 20 minutes after being added to the spa with the jets on high to thoroughly mix it. Approximately 3 to 4 hours later, the chlorine reading should be half or less as much. The reason for this is that chlorine does not survive for long in hot water, but 3 or 4 hours is more than enough time to sanitize a typical spa. Then once a week you should shock your spa with 5 to 7 times the normal dose rate of dichlor. This will burn off combined chlorine which is the stuff that gives off the chlorine smell and does no useful work as a sanitizer.
To round this out, for bromine the level is typically 1-2 ppm but it must be at that level constantly because it is much less effective and it needs more time to kill bacteria. Combined bromine is still effective as a sanitizer, but you should still shock especially if your "bromine" is three quarters chlorine anyway. You can use dichlor to shock bromine, but be careful to keep dry dichlor and dry bromine separate as they are dangerous when combined in the dry state. Alternatively you could use MPS to shock and that is true for both dichlor and bromine.
Regards,
Bill
