Not a life straw, but I bought a 30 gallon Frontier Filter for a belt PSK. Someone told one of the survival guys I follow that it's very ineffective and that I should use the Aqua Mira tabs in conjunction with it. This seems to have been a waste of money if I have to use tabs. And there's no indicator for when the filter has reached the 30 gallon mark. Any thoughts or suggestions on this?