Freezing membranes

[Tapper705]

Running our RO for the first time today then there will be an extended freeze for 2 weeks. Would it be better to take the membranes out and store them in the storage canisters inside, or completely drain the RO and let them freeze? Does freeze/thaw reduce the life of membranes? The RO is a CDL hobby 200.

[mellondome]

Don't let membranes freeze.

[madmapler]

Most guys keep their ro in a heated space. Freezing can destroy a membrane but not always. Mine froze in single digit temps this year and they still work fine. I was fortunate.

[maple flats]

Unless the equipment mfgr says it can freeze, you must keep it warm enough not to freeze. There are only a few that claim not to need to be kept warm. Heat is generally a small, well insulated room with a heat source. For a few seasons I used 3@100 watt bulbs on a line volt thermostat to do the job, then I changed that and put in a portable electric heater. I have now gotten an 8000 BTU propane direct vent wall heater with a theromstat that will be connected this year. On the simpler end, heat can be an insulated cover with a heat source inside or you can remove the membranes, take them inside and drain the unit components so freezing won't wreck it.