Sharing drain line between ROI and dose

[turbo2oh]

I have my RODI drain line leading out of my fish room, around the corner, and tied in to a sink drain. I’m also planning to configure my Neptune DOS for automatic water changes. To simplify plumbing, and avoiding having to drill out another hole, and trying to cram another line behind my baseboard, I’m considering adding a tee to the drain line. The RODI and DOS would essentially share the drain line, any thoughts on this approach?

 

[KrisReef]

I'm not sure if the pressure difference between the two lines might create an issue? Otherwise, a drain should work?

 

[Gregg @ ADP]

Gravity is your friend here. If the T is above the drain, you should be good. If you start expecting water to go uphill without a pump/pressure, you’ll be disappointed.

 

[cilyjr]

What is the diameter of the existing line?
Is it rigid or flex tubing?

I as because you mentioned behind the baseboard so I am guessing you have a single 1/4 inch tube running to the drain. You could try it.

If both are running simultaneously, I could see back pressing effecting the flow restrictor on the RO unit.

 

[turbo2oh]

What is the diameter of the existing line?
Is it rigid or flex tubing?

Standard 1/4” RODI tubing

 

[cilyjr]

It would probably be best if they went to 3/8 at the tie in, but still probably would work. How long is the total run?

 

[turbo2oh]

total run from DOS and RODI to sink drain is probably 20’ only because it wraps around a doorway

 

[Dom]

I have my RODI drain line leading out of my fish room, around the corner, and tied in to a sink drain. I’m also planning to configure my Neptune DOS for automatic water changes. To simplify plumbing, and avoiding having to drill out another hole, and trying to cram another line behind my baseboard, I’m considering adding a tee to the drain line. The RODI and DOS would essentially share the drain line, any thoughts on this approach?

Nice idea.

RODI drain line tubing is under pressure. If the Neptune DOS is also under pressure, I would think it will work.

However, if you are going to rely on gravity, I don't know that standard RODI tubing diameter will allow for efficient drainage.

 

[cilyjr]

I think you're ok. Maybe use a wye instead of a tee. Maybe check valve on the RO waste closer to the unit then the wye. If needed, replace annually.

 

[turbo2oh]

Nice idea.

RODI drain line tubing is under pressure. If the Neptune DOS is also under pressure, I would think it will work.

However, if you are going to rely on gravity, I don't know that standard RODI tubing diameter will allow for efficient drainage.

Not sure what you mean by rely on gravity if they’re both under pressure.

 

[Dom]

Not sure what you mean by rely on gravity if they’re both under pressure.

Pressure from water input means pressure on the output of your RODI system.

If you put your finger over either output of the RODI, you wouldn't be able to hold it because of the pressure coming from the input side. It would be like trying to stop the flow of water from the tap by placing your finger over the faucet.

A gravity drain would be things like the drain in your bathtub.

No pump or pressure is required to push water down the drain, it requires gravity only. The narrow diameter of the RODI tubing wouldn't be effective if you are relying on gravity to drain through the tube.