Help with RO/DI filter system.

[Hangman]

I have recently installed a Coralife Pure Flo II RO/DI system.
It has been in use only about 3 months.
However, the TDS readings on it are out of whack.

My feed water reads 230
Last month, the RO read 25 and the DI also read 20.

Today, I tested it and the RO reads 137 and so does the Di as well.

I figure that the membranes and filter elements should last longer than 3 months.

Is there something I am missing?

Any help or experience is apprecated.

Thanks,

Hangman