Is there a significant difference in the quality of bromine? I can buy 50 lbs. of Hydria Clear bromine tablets for $260. The same amount of bromine from In-The-Swim is $470. The Hydria Clear brand says it provides 65% available bromine; 30% available chlorine. The other brand says available bromine is 61%; available chlorine 27%. Both brands highly rated on Amazon. Why such a difference in price???