It can be a pain if your gonna do straight RO water. I have a 35gpd four stage RO unit that I need to hook up. I need some new filters for it as well. Anywho, I had a 50gal trash bin that I filled up twice a week. It took quite some time to fill up, and I couldn't do water changes until it was ready. It frustrated me having to wait to do water changes, I like being able to do them whenever I need to/want to. I still didn't go 100% RO water though...not even 50/50. If you are gonna do RO, get one that at least does 30 or more GPD, other wise you will be waiting for quite some time...haha.