Back in 2011 we had a 7 Stage Reverse Osmosis Filtering System installed... Since then we've had the 3 large filters that sit vertically changed out twice as recommended by the Installer each time..

As were talking Well Water, issues with Hardness & Iron and my Quest to draw Good Clean , Safe Drinking Water... I've discovered armed with the proper wrench clamp to loosen the canisters holding the filters, I can purchase filters directly saving a ton of money.. Plus I wonder if in fact a 7 Stage Filtering System was all that necessary?

What I Query though is for the remaining 4 smaller filters that sit horizontally on top.. How often do they need to be changed out as it seems to be a bit more involved replacing them..

The Water Test Results continue to come back 0 coli / 0 E-coli , PH levels are well within an acceptable range...

7 stage is pretty heavy duty. Not sure you need 7 stages. What was e. Coli levels before treatment? Costco sells a 5 stage for less than $200. What are filters costing? Iron filters are pretty expensive if using green sand.

Who directed you to this particular filter? Now that you own it its pretty much a moot point, its yours so I am not clear why/what you are asking if it was necessary. Yes you can save a ton of cash buying filter on the internet and doing your own install. What brand and model did you buy so we can check on those top side canisters

A 7 stage system may not be necessary, but it is always to be safe than sorry. Buying the filters online is usually much cheaper. As for the filter on top, one would be the membrane, which is usually changed every 2-3 years. This is the heart of the system, and want to ensure you keep this running smoothly. The other stages are probably an inline DI resin stage, an inline polishing filter, and either a UV stage or re-mineralization stage. Generally, these are also replaced every 6 months or so. However, if you have a UV stage, I am not sure when this would be replaced, nor is it really necessary on a reverse osmosis system, as everything the UV is intended to kill or neutralize is already removed by the reverse osmosis membrane as viruses, and bacteria cannot make it past the small pores on the membrane.