almost giving up on the hobby

[Amadod2]

So i have reached a point in this hobby where i have no idea what to do next! its just one problem after the next and the worst part is i cant seem to get a hold of the problem then a new one comes out. i was having a phosphate issue, so i decided to do more water changes and invest in a brs rodi unit, after two months of water changes my phosphate went from .25 to .15ppm i couldn't really figure it out until i tested my rodi water and it was .15ppm, so i called BRS and they told me it was the water in my are wasnt good, i live in surrey/langley area so that waster isnt that bad. their solution was from me to add gfo to my rodi water storage container and get a TDS meter for my rodi unit.
im just frustrated as it seems im losing corals every week, cant get my phosphates in check and im being told that theres nothing really that can even measure the phosphates in rodi water.

my tank:
cal 450
alk 8.5
mg 1400
phosphates with hanna checker .15ppm-.25ppm

if anyone has any tips im more then willing to hear them out, please and thank you!