I do for a couple of reasons/ One -- I live in an apartment, and while I make my own RO, having a larger mix station for salt is problematic. I still probably would do so except the Saltwater I get is so close to be the exact same parameters week in and week out I figure it's just easier than doing it myself. As to saving money -- no, it's more expensive.
Maybe sometimes one needs just an excuse to swing by the LFS and check "what's new"
I had to carry the SW and RO from ~12 blocks away, live in an apartment as well and back in those days, landlord said no to installing an RODI unit under the sink.
I buy water every week for the same reason as Bruce's. Apartment is too small to have a RO/DI setup. Though recently I am pondering about getting a Aquatic Life RO buddy, but not sure if the water quality will be good enough.
Wow! I thought those people whose get water from LFS are beginner. I didn't expect that many people from this forum lol. I also I didn't know LFS sell natural sea water. May be I should get a few gallon once a month. Thanks for bring up this topic!
I think that a lot of us that buy at the LFS do so specifically because it is natural seawater. By doing so it is very "stable." It has nearly the same parameters every time I pick it up so there are no swings even when doing a large water change. At least that's my theory
It is more expensive though. I pay $1.00 per gallon. I think I once figured it would cost half as much to make it.
The issue I have with buying water is you still need hog up storage all the same. Probably would need to store even more since you can't make more on demand for those "oh-crap-midnight-waterchange". So my motivation to make water is pure laziness and lack of time.
On seatwter, IIRC Richard has natural sea water delivered 400g every once in awhile?
Having lived in San Diego for a number of years, I do miss getting free ocean water. Scripps Institute uses natural ocean water they have filtered through their systems and offer it free. You just need containers. I often times wonder why people have this notion it is not appropriate for their tanks.