What do you think about this for a 1000l spa @Corona ?
https://m.bestwaycorp.com/Product/Item?id=1060340XXX25
It seems to be a small salt chlorinator for spa’s but haven’t found any info yet on whether you can get replacement cells for it.
0.5g/l at €130. It makes a 25g/l Gensalt at €1000 look like a basement bargain…, and the Gensalt has a self cleaning plate stack 
I didnt read that. Just cleaning with 50:50 vinegar and water.
From a tech point of view its a low power unit which I find a bit worrying as most are 24v therefore thevplates in the cell maybe closer together to accomodate the lower voltage. That could mean calcifying quicker.
This has got completely out of hand as far as I’m concerned. 23 years of galets and ph (up or down) and some neat advice from corona and no big problems and no problems at all. But it makes for jokey sci fi reading over breakfast!
Thought it may have a DC-DC step up convertor, but if not as you say the low voltage is a bit worrying. Have you seen any other salt chlorinators that are suitable for a spa ?
Indeed, but no good for a 1000l spa 
Because being mainly pool based I havent paid a lot of attention to spa equipment except when something breaks. A friend has a the diamond boron doped chlorinator on his model which I recommended from others he was looking at. Can take a look around though.
There are a couple of others you can buy in the US, but no European stockists that I can see.
Indeed, I did not intend the comparison to be derogatory towards the units intended use - more I was intrigued by the economy of scale…no longer will I regard the 25g machines as expensive!
How about this one:
https://www.amazon.co.uk/dp/B0D8VHQN2X?tag=marketitaly0b-78158-21&linkCode=osi&th=1
Much more realistic than the floating one and at 8g/h production means it is only theoretically necessary to have it running for half an hour to get 4ppm…I confess to not knowing how a spa is plumbed - I presume the water leaves the tub to be filtered and re-enters the tub after?
I do not imagine it is self cleaning.
My only concern are any metal parts or fittings that the salt may damage. Generally pump internals and fittings such a screws may need to be swapped for 316 stainless steel etc
A bit pricey but has a large cell so hopefully lasting longer than a tiny cell version. Seem popular in the US.
Look at this product that I found on google.com ControlOMatic MegaChlor Saltwater Chlorine Generator
Moving way up to the other end of the scale - have you ever come across a BSV chlorinator and care to share experience?
I have only ever used Zodiac, but the highest production they do is 25g per hour. With the climate moving up from N Africa, things get pretty hot now - it has been 34+ the past few days and we are not halfway through June - so I fear that I will be battling to keep the pool at 3ppm. I am now looking at maybe replacing the SWG with a 50gram machine when the current cell needs replacing (it is on its fifth year now)
Yes, I was looking at that one, but apparently they went bust last year and there are counterfeit versions online that perform poorly. I went to their website to try to confirm and there is just a blank landing page.
Interestingly, I have entirely dismantled the pump and pipes on my spa when the pump failed. They sent me a new one by post FOC to fit myself. There don’t seem to be any exposed metal parts at all. The rotor and stator assemblies are both encased in plastic and there are teflon (I think) bushes and seals that support the rotor and protect the steel pin that runs through the centre of the rotor.
My go to for spa info and help are in the UK and I havent got the engineers contact details with me so it depends if you can wait 6 weeks?
It’s OK, I think the Bestway one is the only real option to buy within the EU. I’m not going to go for the ControlOMatic ones as it’s likely you’ll get a counterfeit. There are several inline ones but that would require me to modify my spa plumbing which I don’t want to do and the output is quite high as well. I’ll leave it for this season.
Ok, let me see when I get back to the UK any suggestions the guys may have. Just back from brico marche and they had this but as you said some plumbing mods required.
Looked at these and the flow rate of the pump in my spa (1200 l/h) is right at the bottom end of the flow rate required for the smallest unit they do, so I’d be a bit unsure of it.