Phosphates or Silicates slipping past TDS meter?

[jostafew]

Hey everyone, I've got a question re. TDI and phosphates / silicates, but first a little background: Ever since I moved from Langley to Abbotsford my tanks have gone to crap with cyano and red/brown algae everywhere (one moved, the other one in the my work office was undisturbed). Everything is the same except for the source water. TDS meter showed reading on source water of about 15-20ppm in Langley which went to 25-120ppm in Abby, water tasted kinda funky too. TDS leaving the RODI went from 0 to 1-2 after moving. Ran this for a while and noticed the problem appearing. Been about 8 months of this.

Ok, changed the first three stages (mechanical and carbon), and DI stage of the filter, TDS on the output side now down to 0 again. Ran that for a couple months, no change (algae that I physically removed had all regrown).

Started running rowaphos in a reactor and another water change, junk grew back just as fiercly...

Down to the question in the subject, will problematic phosphates and/or silicates show up as TDS for my meter to detect or is it possible that junk is slipping through because I didn't change the RO stage of the filter (didn't change because TDS now reading 0ppm)? I'd like some feedback before I throw money at a full set of filter elements.

Thanks in advance