If you want to change everything all at once, I'd make sure you get a filmtec membrane which at retail, by itself costs what the Geekpure set does. Think I'd go with this, should go a year and then get just 2 good carbon blocks like 2x MatrikX CTO plus and a sediment filter. You can then cycle the 3rd stage to 2nd and only get 1 the year after. Always change your sediment filters-those don't super matter (quality wise) and even the good ones are less than $5. https://www.amazon.com/dp/B01M3O7F2Y