Auto water change oddity

[painter1982]

I have an awc in my basement right below my aquarium. I use a Neptune dos pump that is about 3 feet above my clean saltwater and 3 feet below my sump where it’s sucking from. In my drain line after the dos I’m getting a grey/tan looking sediment after the pump head. On the fill side I’m getting black in the line only after pump head. Doesn’t look like sediment. Just appears to be on tubing. No metal in line for any of this. I use regular clear RO line. I’m assuming the pressure is causing some sort of precipitation. The lines are in complete darkness 99% of the time. 65 to 67 degrees. I change 2 gallons over a 24 hour period. @Randy Holmes-Farley would probably be the expert on what’s happening. Anyone have this issue and know how to fix it?

 

[Dan_P]

I have an awc in my basement right below my aquarium. I use a Neptune dos pump that is about 3 feet above my clean saltwater and 3 feet below my sump where it’s sucking from. In my drain line after the dos I’m getting a grey/tan looking sediment after the pump head. On the fill side I’m getting black in the line only after pump head. Doesn’t look like sediment. Just appears to be on tubing. No metal in line for any of this. I use regular clear RO line. I’m assuming the pressure is causing some sort of precipitation. The lines are in complete darkness 99% of the time. 65 to 67 degrees. I change 2 gallons over a 24 hour period. @Randy Holmes-Farley would probably be the expert on what’s happening. Anyone have this issue?

No experience with the subject, making this a guess: heat inside the pump head causes a small amount of precipitate and the black bacteria growth.

 

[TokenReefer]

Are the clear ro lines you're using getting light? That'll grow stuff inside..

 

[painter1982]

Are the clear ro lines you're using getting light? That'll grow stuff inside..

The lines are in the dark. The black starts right after the pump head. None before it.

 

[exnisstech]

All of my manual water change hoses get black inside of them. They're stored in the basement. I guess its some type of fungus or mold but really don't know. Been using the same hoses for over 15 years and there haven't been any issues that I'm aware of.

 

[painter1982]

All of my manual water change hoses get black inside of them. They're stored in the basement. I guess its some type of fungus or mold but really don't know. Been using the same hoses for over 15 years and there haven't been any issues that I'm aware of.

It’s really odd that it’s only after the pump head. It’s not on the suction side, just the pressure side. The lines are within 3” of each other.

 

[BeanAnimal]

Are you sure that it is inside of the tubing and not just discoloring the outside? The rotation and occlusion cause wear on the tubing, rollers, bearing surfaces and cover. This results in extremely fine dust mixed with lubrication and humidity and can settle on the output side of the tubing set. It may not be happening here, but is something to look at depending on the cover design.

How long are the discharge tubes on each side and are they open to the air? How far does the discoloration extend?

Lastly, if it is inside the tubing, the same microscopic wear occurs on each occlusion. This could over time create rough surfaces and particles where bacteria can grow and expand down the tubing. It can't easily migrate the other direction due to the constant occlusion blocking it.

Those would be my guesses at least.