Quote Originally Posted by BeakerBob View Post
See if you can get some in a small container, then add some vinegar. If it dissolves, then it's probably some minerals (carbonates, iron, etc.).

If it doesn't dissolve in the acid, get another sample and this time add some dilute beach. If it goes away in bleach, then it is probably bacteria.
Does this mean that the RO filter needs changed? I'm waiting for new ones to arrive any day now. Do I dare use this water?