For questions #$20$ to #$25,$ What happen to following parameters: Goes up$,$ goes down or stay the same

$20.$ From the feed end to the brine end of an RO unit, the feed water TDS $(m\frac{g}{L}$

$21.$ From the feed end to the brine end of an RO unit, the osmotic backpressure

$22.$ From the feed end to the brine end of an RO unit, the permeate TDS $(m\frac{g}{L})$

$23.$ From the feed end to the brine end of an RO unit, the feed pressure

$24.$ From the feed end to the brine end of an RO unit, the permeate production rate of each membrane

$25.$ From the feed end to the brine end of an $RO$ unit, the water flux rate.