Rrasco is right BRS resin doesn't seem to last as long as BFS... But if you go by color like I was, you will be going through it bi weekly, lol I was.... Until i bought all my tds meters... But it still doesn't seem to hold up much longer... I stick with brs cause it can be bought locally.. I always say I'm going to buy a batch from BFS but never get around to do so...

as a matter of fact I have a set of BRS filters I need to install.... It's always good to keep one set on hand..