[Hardware] RO vs. DI & what about diatom?

	I've got phosphates & silicates & a pH of 9.8 and a high kH.

	I want 0 phosphates & 0 silicates & a pH of 5.4 and a dkH = 1.

	So, I've looked into RO and DI units and I'm curious about the 
common opinions of them from people w/ plant tanks.  Also, has anyone here
made their own DI unit?

	Further, do plant people here use the diatom filters and if so,
how and why do they like them?  If not, why not?