I recently upgraded my entire system. I ended up going the BRS route with my system, but the same thing can be done without having to buy the complete system. It's just convenient because they have everything pre-installed and ready.
If I were you, I'd consider getting a setup with the triple DI canisters. Cation, Anion, and then Mixed Bed. It forces your system to deplete the most commonly charged particles with the cation resin first. Making your next two stages last much longer. So you'll likely change the first stage of DI 2 or 3 times before ever needing to change the second. And the last one usually longer that.
No matter which way you decide to go, replace every single filter in there and start with new ones! Plus add on some accessories to help you better track the filter life cycle. Not necessary, but definitely useful. Like a pressure gauge before the RO membrane to keep track of your differential. Triple TDS meter to monitor before each stage of DI.
Here's my concern with your system.
- You can't see your 1st stage filter. The one that will get gunked up the soonest and cause diminishing returns the longer you go without changing it out. It's also the cheapest to replace more often. Easy enough to just get in the habit to open it up every month and check it. Toss it when it starts getting too discolored. Minor inconvenience that it's not see through. You should be able to find clear replacement chambers btw.
- The two PreFilters I am assuming is regular ole activated charcoal filters. But it doesn't actually say that. What filters are in there? On top of the RO membrane, it says it's an order and taste filter. What's in it? Normally the charcoal pre-filters will take care of toxins as well as odor and taste.
- I personally don't think you will need that one on top of the RO
Upgrading to higher flow rating is all about the pressure from your supply and pressure loss between your filters and RO membrane. Also, the type of membranes that are compatible with the housings. Yours looks like most standard DOW branded RO housings. So in theory, you can change the membrane to a 75 gpd (not gph), as long as you can maintain the correct flow and pressure to ensure the best product/waste ratio. What is you actual supply source pressure? Will you need a booster pump to maintain the required pressure?
