I did my normal Saturday maintenance and I had some RO filters and resin I picked up from BRS a couple of weeks ago, so I swapped them...I let 5-10 gallons of water flush through there before putting the water into my mixing bucket. I then made 5 gallons for my frag tank and was about 5-10 gallons into my brute for my display tank when I noticed the color changed to light brown..... The same color it says that it turns when expended......It's never done this with buckeye resin......My membrane was replaced not to long ago, so what happened? I don't have a TDS yet, waiting to pick one up Wednesday... The one I had crapped out on me....Can my water be that bad? At the most 20-25 gallons ran through it before the color change.... Only half is light brown.....