If there were a viable alternative to buying your own tanks, I am quite sure that most people would opt to rent. No storage issues, no retesting timescales to worry about etc.
Rental really only works where shops are local and have the facilities for their own fleet of rental tanks (space, compressor, testing facility, tank monkey) - people could look at the ease of renting vs having their own and decide the costs are reasonable. If there were a sizeable need for rental tanks the local shops would have them however that is not the case.
I will be doing a trip in April with a shop where I will rent tanks (they bring 2 vans full of tanks for everyone) - 4 tanks for 2 days diving with no option for refills. No way I could take my own 2 and make 4 dives work. Not worth me having 4 tanks myself though.
Sheesh, I did something wrong. I just tested 30 of my cylinders. I may have to start getting rid of some. Doubles, stages, bailout..... Actually all I need anymore are the three for the rebreather, one for the booster, diluent, O2 and Argon. They just kind of collected as my diving progressed. It all started because though the dive shop was local, its hours were difficult. But in the end, as stated before, the really only reason for an OW diver to own his own cylinders is CONVENIENCE.
Maintenance can definitely become an issue. Here in the US - Hydro every 5 yrs ($50), Visual yearly about $15. Fills depend on location and can be anywhere from $5.00 to $10.00 plus. More for Nitrox.
The outside storage bin looks interesting, especially if sort of watertight.
An independent diver
There are around 25 cylinders in my shed.
They range from 1.5L to 50L.
Keeping them in a shed is fine. Like always, keep gas in them to keep the insides dry
Remember anything you read on the internet was probably written by some guy sitting at home in his underpants! Including this !!
Illegitimi non carborundum
The only people it might/(/does) work for are charter boats where they might get a profitable charter that they wouldn't otherwise, this would be different if everybody hired them I suppose. (thinking scapa where they'd be in use every week)
No brainer for me, you've only got to dive 10 times and you could buy a tank. I never like renting anything for that reason tbh. Though it does trip me up occasionally when I run out of out of test tanks to take on trips away.
The example I gave of Cardiff Scuba was £4. If you take the price of a new tank as the GoDive price it is £155. Ergo 38 rentals to buy the tank. Testing is appx £80 over a five year cycle or £16 a year or four rentals. (assuming no shot blast).
Financially renting is sensible if you don't dive all that much. So it is convenience. I used to rent tanks when I lived in London as my LDS was not far away, but (like many other people on here) that option is not a working solution where I live now.