Are Test Kits Needed W/ Ro, Di, Or Rodi Filters?

[steven's un]

Does RO or DI or RO/Di eliminate use of test kits?
if YOU HAVE AN RO, RODI, OR DI FILTER, DOES THIS MAKE THE COMMOM NITRITE AND NITRATE AND AMMONIA TEST KITS A WASTE OF MONEY.......WILL THESE BE GONE FROM THE WATER?

 

[steven's un]

Thanks for the help!!!!!!!!!!!1