I have been thinking about buying a automatic water changer for my 300L freshwater tank. I was looking at the 'Complete Automated Water Changer' (http://www.aquariumonlinesupplies.com.au/complete-automatic-water-changer.html)
or something like the 'Kamoer F05x system' (http://www.sydneydiscusworld.com/kamoer-f05x-wifi-wireless-dosing-and-water-change-system/)
Does anyone have any reccomendations for auto water changers? I would prefer to stay away from going DIY.