Please critique my nitrate reduction plan.

[Rellik]

Background: new to salt water reef keeping. 6 months in on red sea s400. Was having some troubles with tank. Fish and softies were not looking or acting well. I decided to have local reef store test my water. Their results were way off of mine. Come to find out I have high alk and low Ca. Easy fix there. But my nitrates are WAY HIGH and Phosphate way low. Red sea test only goes to 50ppm and it is maxed out.
My plan is to start dosing nox pox and add a nitrate filter for 1 week. For added help.
I do also have a 5g hob refugium. Any reason not to add the nitrate filter (poly filter or other brand) to give me a boost as I start dosing?
Phosphate. 02

 

[Tahoe61]

I would look at an Algae Turf Scrubber/ATS and water changes before starting dosing.

 

[Luno]

A 5g hob fuge will do very little, realistically the smallest fuge for a tank should be minimum 10% of display volume to be adequate as nutrient removal.

I would do a couple 30% water changes get the system down a bit. And then start dosing to reduce nitrates.