[Slash]

I was bored on Sunday so decided to transfer pure water from my static tank through the portholes into my 4040 van mount system only for a few minutes and was surprised to get waste!

[Alex Gardiner]

Whatever quality the water is going into an RO membrane you will always get waste water. In this case the waste will have been clean. The flow is always set-up to wash the membrane surface with waste to remove impurities.