New RODI media spent in a month?

[MatthewScars]

I have a 40g cube that I just started. So the RODI has output 50g (+sump) plus top off... so maybe 75-100 gallons total. I looked at the RODI today and the DI is totally spent. I live in Brooklyn NY, and my normal TDS is 35ppm. Im sure you know NYC has good water quality.

I was getting 550 TDS with the RODI. So I disconnected the DI and ran the system as RO and still got 447ppm. Oddly, the sediment filter looks pretty rusty, but i dont know if that would attribute to this. It's only been a month, so I can see the media being actually used up in that short of a time wthout there being an issue.

My water pressure has to be around 90-110psi, but it still comes out of the RODI at a normal slow pace. I leave the output tube in the tank, so I was possibly thinking a back siphon, but then again I have no evidence of this and where would the water go? Other than that, I am at a loss.

EDIT: The ENTIRE unit is one month old.

 

[Buckeye Field Supply]

If your tap water is 35 ppm, how can your RO water be 550? Something is wrong.

How are you making these measurements?

Russ

 

[saltwaterinbrooklyn]

yo mathew im in brooklyn as well i got 35 ppm from tap and i can draw 000 from just the first sediment filter with out using the other two stages, i think something is going wrong with your unit or perhaps your tds meter is inaccurate , where in brooklyn are you?