David S
Aquarium Advice Addict
Once you've sorted that use this as an auto RO water top up.try getting a Little giant pcs-10 (www.hawco.co.uk/Little-Giant-Pumps_32_0_m.aspx) parstaltic pump from your local air conditioning supplier,then dissconnect the push test switch on the side and connect your two leads from your float switch instead then just plug in your pump.These pumps use very low voltage off the pcb's to the switch so you won't need a transformer,relay or in fact anything else it's all in the pump.another benefit is the water doesn't go through the pump,it uses a rubber tube which can be removed in 30 seconds and replaced when clogged or every 6 months. This is what I have used on my refugium for the last 8 months