Reverse Osmosis and Hard water questions

WHats up folks..

I have a RO Unit with well water for the source.
My well water is over 320 ppm and I'm concerned about filter life.
If you have water as hard or harder with a RO unit;
are you doing anything extra to help lengthen your filters life?

I'm considering adding a 1 micron sediment filter to the system with the idea
it could only help get the volume of water the other filters are specced for.
The chain would go like 5 mic sediment filter > 1 mic sediment filter > rest of filters.
It might be overkill, but I also have a booster pump for the system that I don't want the hardness of the water to kill..

I usually clean my prefilter every 2 weeks or so, and the carbon filter at least once a month. I'd probably recommend rinsing the filters out as I do, seems to almost double the life. I am on a deep well incoming water is just under 400 PPM.
An additional prefilter like you mention would definitely help, I'm thinking about getting one myself. I only average about 20-30 gal/day, forgot to mention I'm running a hydrologic stealth 200.
Do you also use a water softener? I have a large softener for the house, but my RO is currently feeding off the main line before the softener. This was how my Culligan system was plumbed, not sure why. I'm going to hook the stealth up after the softener and I suspect it should dramatically increase filter life.
What type of RO unit are you running?

Hi Stems&seeds thanks for your response!

I have no filtering at all in my house, like you though deep well with 350~ ppm
I have a 5 stage unit- 75gpd system no name from ebay. I'm around the same amount of water a day as you.
How often do you need to replace your filters? When you said it almost doubles the life of the filters does that mean you can get the volume of water they are specced for?
Or do you just go by how many months old they are?

No one else on well water? Everyone else is on city water? Or don't you pay attention to these details?