RODI pressure drop

[StrangeDejavu]

I'm using a SpectraPure 90 GPD RODI and I recently noticed a sudden drop in pressure. I've gotten a consistent 61 PSI through the bathroom faucet since September 2015. A week or two ago, I noticed i'm sitting at 50 PSI now every time I make water. My carbon and sediment filters were just changed on March 11th. My previous filters lasted 7 months before I changed them, and even then, they looked clean. Sediment was barely discolored but I had bacteria concerns running them longer than that. Does this sound like a sediment/carbon blockage or is it time to replace the membrane?

Some info if it helps any: 1 Micron Premium ROsave.Z Sediment, BRS Universal carbon block, BRS color changing DI resin and SpectraPure stock membrane. Tap TDS is 165, post-membrane TDS is 2 or 1, depending on how long I flush. Post-DI is 0 TDS.

[ccrider93]

Could it be a drop in input pressure? I know I've had some on and off, depending on what the water company is doing. I fixed this by taking the 3/4" input and Y that off into 1/2" to maintain a lot more pressure on the intake side, plus the outside hoses go really far. :)