View Full Version : Waste Water

06/01/2007, 04:54 PM
Wondering why more people don't use those auto shutoff valves for wastewater when the RO water output is blocked (by say a Kent Marine Float valve)? Lots of threads on how the worst thing that happens is waste water flows until they shut it off.

Similar to what is used on RO units attached to drinking faucets:

http://www.marinedepot.com/ps/ps_ViewItem~SearchStr~kent%20marine~action~view~idProduct~KM1651~idCategory~FIRORAFV~category~Kent_M arine_Float_Valve_Kit_For_RO_and_RO_DI_Units_Saltwater_Aquarium_Supplies_Reverse_Osmosis_Accessories _Float_Valves~vendor~.html

or this: http://autotopoff.com/products/MISC/asv_instructions.jpg

I was thinking of using this to fill a auto topoff container through a Kent Marine check valve as a backup to a solenoid valve and electronic float as the primary shutoff.

I added this to the lower reservoir of Ken Stockman's topoff design as an additional safety device: http://web.archive.org/web/20060224153133/http://home.nc.rr.com/stockmanreef/diagram_of_setup.htm

06/01/2007, 05:14 PM
If the RO unit has an ASOV (Auto Shut Off Valve) built in, the waste line should stop any output when the RO system feels backpressure. So when the Kent float valve rises, it seals the outlet of RO/DI water, backpressure builds up in the unit and the ASOV shuts off the water supply to the unit. No more waste water.

Closing the waste line would be a stop-gap solution, and something you'd need to remember. Plus some put a small ball valve on the waste line as a flow restrictor so that they can increase RO/DI production rates. I'm not sure what would happen if the unit was on and the waste line was blocked off.

06/04/2007, 06:06 AM
Yeah, my RO didn't come with a built-in ASOV, but I got one of the aftermarket valves (what the links referred to). I didn't realize some came with those built in--I guess that's why people never mentioned needing one. Pretty sure my SpectraPure RO manual said not to restrict the waste water output, as it decreases the RO membrane life, so I don't intend on valving the waste water output.