I went through some RO "pain" when I first set up with it, but have since gotten a handle on it. I purchased a 5 stage Water General system off of ebay. What appealed to me a lot was the water hookup. They don't use a piercing type valve, which I've always hated, but instead a fitting which tees into the supply line where your sink hose hooks up. Much neater, better flow, and no leaks.

There was mention in the FAQs about a permeate pump. So I looked into it, and found one in the Water General ebay store for $45. A permeate pump uses no electricity, but the pressure in the waste water line to run it. It significantly improved throughput, and reduced waste water by a third at least. As I tend to drain the storage tank each time I draw water, the mfr recommended removing the system's shut off valve. Doing so make the permeate pump the shut off valve. No guarantee it will work with your system - it depends on the design. But it costs nothing to run, and makes the system more efficient.

An alternative is an electric booster pump, which brings the incoming pressure up to 70 or 80 psi. Better throughput, but no reduction in waste water.

If you need a lot of RO water for growing, a larger storage container would be in order, as opposed to filling small containers constantly (been there, done that, hated it). I ordered a 55 gal water storage container, and had an optional bulkhead fitting installed. Added a 3/4" ball valve with a hose adapter on the end to that fitting. In the top bung fittings I added a float valve in one, and drilled the other as a vent. Teed off the RO dispenser supply line, added a manual shut off valve, and connected that to the float valve. Now the barrel fills with RO water overnight, and the float valve automatically shuts off the flow when the float valve raises up. A short length of garden hose connects to the ball valve, and I can fill a 2 gallon pail in about 30 seconds. No more puddles on the floor.

HTH