Our pool is currently manually chlorinated using granulated chlorine, and I'm already finding it tedious. The pool is marble sheen in pretty average condition and there are also a couple of places where the marblesheen is gone and concrete (but not reinforcement) is showing.
My question is firstly, is it worth the money to convert to salt chlorination, and secondly, should I drain and refinish the pool before doing so? This is on the cards anyway, but I was thinking later rather than sooner.

Convenience is what SWG's give to you. You have to decide if it's worth the price....no one else can decide that for you.

X2 what Dave said. It's really about a convenience factor, not necessarily about saving money. I give convenience a high price.
You can resurface now or later, it doesn't matter. Compupool is based in Australia, I've been happy with their product.

Be aware that continued use of granulated chlorine is not advised. You are either adding calcium CH or stabilizer CYA with the chlorine and both are bad if the levels get too high.

Posted from my Droid with Tapatalk ... sorry if my response is short

Liquid chlorine would make dosing much easier. (not to mention balancing)

Until you go SWG.

As far as money goes for residential system it will probably take about 5 years to break even, depending on how much you pay for it.

Convenience of being able to leave your house unattended for a while is priceless though.

Bingo. I travel for a living, so priceless is the right word.

I can get called out pretty much anytime for maybe two to four days at a pop. Going with SWG made it much easier to simply "tell" the wife exactly what to add (for me, once cup of bleach after everyone gets out of the pool and it get's covered). Combined with the SWG, I could leave the pool covered and alone for a week without any noticeable problems. First thing I always did though was test water when I returned, about half the time nothing was required.

Life has been much better with a SWG than it was without.

Bob E.

I find a stenner pump setup to be a pretty convenient option speaking as someone who does not like the feel of salt water pools. Very easy dosing especially when connected to your automated system.

I had a Liquidator, and I got completely tired of hauling all that bleach. Those injection type systems might be OK on a smaller pool, but for mine it was still a hassle. My LQ would only hold enough bleach to go about 5 days, after that I'm in trouble. There were times I was gone for two weeks straight last year. Even if the wife is home, she forgets to add the bleach and I would come home to a green pool. Now with the SWG I do not worry at all, and just know I'll have to add some muriatic acid when I get home.

Yes for a pool your size I would imagine that liquid would be a hassle! I have a 15 gallon tank and am having good luck. For an even smaller pool it should last substantially longer. I also have an unused liquidator waiting to be used for something. Too uncontrolled and small capacity IMHO.

I installed a SWCG on our pool about a year ago, and really like it overall. There are some downsides to consider that may lead you to other options. First, apparently salt can have deleterious effects on some stones. I have not seen this yet, but again, this has only been in place on our pool for about a year. Second, an SWCG will not control pH, and you may likely find that the benefit of not having to manually chlorinate your pool is offset to some extent by rising pH requiring weekly (or more often) muriatic acid additions. In our case, this was particularly evident when we first switched over from liquid chlorine to the SWCG. You will need to make efforts to reduce the total alkalinity, but regular acid additions will be necessary. Third, if your water temp drops below about 59 degrees F, which I would bet it likely does in Melbourne, the SWCG will become less efficient in chlorine generation. In my case, the generator shuts itself off when it gets below 59 to prevent any damage to the unit. Thus, for the several months during the year when the water temp is below its operating range, the SWCG is useless. This caveat is itself offset by the fact that the pool does not consume nearly as much chlorine at low water temps, especially if you have enough CYA to protect the chlorine from UV. As others have mentioned, a fourth issue is that the cells themselves degrade over time and need to be replaced... these are not cheap.

So, these are important issues to keep in mind. Salt systems are great, but they are not perfect. An alternative that might be of greater utility would be something like Pentair's Intellichem, which uses dosing pumps to feed chlorine and/or acid based on continuous reading of oxidation/reduction potential (ORP) and pH, respectively. These are a bit more expensive in the short run, and their long-term reliability remains to be seen (at least with the Pentair units).

This is usually easily avoided by proper water balance. The main time it is an issue is when you have high TA fill water.

Units like the Intellichem, or anything based on ORP, have a whole world of problems that are best avoided. Bleach pumps are great, just avoid the ORP sensor.

True, but it's a battle I still wage, as our fill water has a high TA and is quite hard (as is quite typical for Southern California). So, I do count that as a negative for my specific situation. That along with still needing chlorination during the winter months, but without an operational SWCG, is really another bummer. I don't have any experience with the automated dosing units that use ORP, and have read variable reports here as to their use. It may be an issue of the "grass is always greener," though I would be interested in looking into pH control, which the Intellichem seems to do well. I would say that overall, our SWCG really does help reduce maintenance, but I may have started with unreasonable expectations.

not working with low water temp might be specifics of IC-60, there are units that don't switch off when the water goes below certain temp

There certainly are some that keep working, but most of the common brands in the US either shut down or limit their output significantly at temperatures below something in the 50 to 60 degree range.

What are the biggest disadvantages of the cheaper units? I have seen the ones on eBay like this:
http://www.ebay.com.au/itm/Salt-Water-C ... 5670wt_949
This offers 2 years warranty, and 30g/hr should do my pool comfotably. Or this one:
http://www.ebay.com.au/itm/NEW-ZODIAC-T ... 1626wt_980
Zodiac is a decent brand, isn't it? 3 years warranty on unit and cell for $800 seems like a bargain. Am I missing something?

never heard of the first unit, but zodiac looks like a decent buy