A general comment: pay less attention to the number of stages. Vendors know that less informed buyers assume that "more stages = better filtration." So you can go out there in the
marketplace, and if you understand what you are looking at, you can find all sorts of oddly configured systems highlighting their umpteen stages. Ugh. Consider these "vendor subsidy systems."
Consider a system with a sediment filter, carbon block, RO membrane, DI cartridge (aka a 4-stage system) with a pressure gauge and a TDS meter as the default configuration. This setup will work just fine in most instances for most people.
Why not add more stages? Well, there are some downsides.
1. Cost. You have to buy and replace that extra filter for the life of your system.
2. Performance sacrifice. You pay a price in terms of pressure loss for each prefilter you add. Needlessly adding extra sediment filters and or carbon filters does little if anything (in most situations) to improve your water.
3. Needless system complications invite the opportunity for problems (e.g., leaks).
4. Maintenance - few people actually enjoy system maintenance once they work through the process a few times. You'll like it less if it is more expensive and takes more time.
So if you think of the 4 stage as a default, why might you add addition filtration to it? For example:
- If you are on a residential well system and your water has heavy sediment loads, you may want to add a second higher-micron (larger pore size) sediment filter ahead of your system. You'd do this to spread the sediment loading over two, rather than one, filter so you don't have to replace them so often.
- If you have chloramine in your tap water you will likely want to add a second carbon stage, especially one made specifically for chloramine treatment. For example
https://www.buckeyehydro.com/chloraguard-chloramine-carbon-block/.
Russ
