Water Making and Mixing

[Experimenter]

Since it is now winter, I am dreading water changes and making RO/DI water. My wife has banished these tasks to the unheated garage! I have a few questions about this.

1. I suspect that most RO/DI filters do not work well - if at all - when the water is too cold (or possibly too hot). At least I remember reading that somewhere. Is this true? If it is, I guess I will wait for a warmer day and filter a lot of water to store, or hook up a scaled down version of the operation to the hot water line in the laundry room.

2. How long can I store RO/DI water in a garbage container with the lid on? Does it matter if it is stored in hot or cold areas? I usually put a heater and powerhead in my RO/DI water to keep it close to tank temps for when it is needed.

3. After mixing a batch of salt water, how long does it stay "good." I usually try to keep some made on hand in case of emergencies. I store it in a garbage container with a heater and powerhead, and the lid mostly closed (except for the cords).

Thanks in advance. I realize these are relatively "beginner" questions, but I have never had an answer to them that I was truly confident in and I have not seen this really covered in even the beginner books.

Take care,
John

[Randy Holmes-Farley]

John:

These are good questions.

Colder water is supposedly less efficient than warmer water. Maybe the pores in the membrane shrink and it is harder for water to get through. Nevertheless, many of us use RO on water that gets very cold in the winter and it still works OK. So I wouldn't worry about it too much.

Stored salt water is OK for quite a while. Over months, calcium carbonate may precipitate, but it will still be mostly OK. Many of us store water for weeks.

RO/DI water can be stored for as long as you want.