It just came with the tunze ato so I am not sure how much the pump is to buy. I bought my ATO second hand and I got a second pump with it in case one fails.how much did your ATO pump cost @Buddy?
That's the one Damn pricey ... I think I am going to get a Nano version.is this the one you were talking about @aussieant32?
http://thereefshop.com.au/index.php?main_page=product_info&cPath=14&products_id=254
Not for me mate. If the float fails and the pump shuts off after 5 minutes, from what I am reading there isnt an indicator this has happened, and it won't run again until you unplug it and plug it back in. So essentially it may not run for days and you not know unless you are checking it regularly.http://www.thereefuge.com.au/threads/tunze-osmolator-nano-3152-auto-top-off.3278/
http://tunze.com/nano.html?&L=1&C=HK
http://www.advancedaquarist.com/blog/tunze-osmolator-r-nano
http://reefbuilders.com/2012/05/22/tunze-osmolator-nano/
Has a 5 minute/1 litre safety top up maximum (ie would only top up 1 litre at a time) - safe enough for me.