I'll bet you never expected getting started was going to be this complex. On the other hand think of all the things you have learned along the way . If it helps any, we've all "been there"
For sure, but it's actuall been pretty relaxing and enjoyable. I enjoy learning stuff....only downside was I underestimated how long it would take and just what a process it is.
Looking at it more closely, this is an RO unit, not an RODI. This just has a second carbon cartridge, whereas aquarium-specific units will have a final stage of deionizing resin to remove ions like nitrate and phosphate that are too small for the membrane itself to remove. This makes sense given that it's meant for drinking water, where that level of purity isn't really necessary. With this in mind, I wouldn't recommend this unit.
They cost a bit more, but I recommend the BRS units. The push-connect fittings are the finest I've seen and use a double-gasket design that holds the hose firmly in place in two places so it doesn't twist around and leak. They also have a dual TDS meter, which is pretty much necessary to know whether your DI is depleted or not. They also have flush valves and pressure gauges which are very useful, although not quite as necessary. Another thing is they come with the Dow FilmTec membranes, which are the best in the industry and really not all that much more expensive than the knockoffs.
For the water supply you can definitely just attach/detach an adapter to the faucet itself, but it might be easier to just get a 3/8" valve adapter. It's real easy -- you don't need to be a plumber to put it in -- you just unscrew the flexible hose from the faucet underneath the sink and screw it in.
I will look into the BRS units. Is there a specific model you would recommend? I've also been advised the Spectrapure units are good.
I'm moving apartments in September and just want something simple that I can easily connect and disconnect since I will only be using it for my tank, not for drinking water.