Rodi drip ???

[BIGG D]

A little back ground info.
I have been considering topping off my sump directly from my RODI unit rather than from a holding container of RO water.I have seen some nice top-off units available with multiple solenoids that look compatable. I have a 175 gallon display with two 75 gallon rubbermaid stock tanks tied in for sumps. I have not determined exactly how much evaparation I will have but I imagine it will be quite a bit.

Here is my question.
Any reason I cant just run my RODI unit reeeeeeally slow and just drip RO water into my sump? I feel like I could dial it in. This actually sounds safer to me than trusting solenoids. My only concern would be how the RODI unit reacts in this set up...under constant low pressure. Would the water quality be affected? Would it still filter properly?

Any thoughts appeciated!!!

 

[Mike31154]

I believe the specs for most RODI units call for a specific minimum pressure, usually better than 50psi for the membrane to work efficiently. No idea how the actual results would turn out at a much lower pressure. Might be best to put that question to one of the RODI system vendors that sponsor here, but I think I already know the answer, not a good idea. How do you propose to control the input pressure?

 

[rdlisby]

I am not sure how well it will do under such a low pressure, I know this is not an answer to your questions but I run the Reef fanatic top of with a solenoid directly from my RODI and it has been great. I put $10 water alarm from HD right next to my sump just incase. Never any problems.

http://www.thefilterguys.biz/top-off_controller.htm

I had a solenoid go out on my whole house humidifier but it stopped working in the close position, I wonder if when they go south the nature of a solenoid would always error on the side of closed.

Just my opinion.
Ryan

 

[driftin]

rdlisby, measure your TDS at the ro membrane outlet. I think you'll be surprised. I used to operate my system that way and the TDS creep out of the RO membrane was really high - I went through DI resin in no time.

BIGG D, are you looking at restricting the outlet of the DI line to the tank, or the city water into the filter?

 

[rdlisby]

I have my after the dual DI unit so it is RODI.

 

[driftin]

I don't think you're following me. Measure your TDS between the RO and DI stages some time. The TDS will probably be much higher than you expect going into your DI stage.

 

[rdlisby]

I must not be, I am sure the RO water is not completely void of TDS that is why we put the DI units after the RO water. That’s why I have to change the color changing DI media once it’s exhausted right.

So lets say the water after the RO unit measures 24 doesn’t the DI cartridges finish that off?

 

[rdlisby]

I went back and found the last reading I had taken and it was 4 after the RO membrane.

How do you use your DI?

 

[BIGG D]

I believe the specs for most RODI units call for a specific minimum pressure, usually better than 50psi for the membrane to work efficiently. No idea how the actual results would turn out at a much lower pressure. Might be best to put that question to one of the RODI system vendors that sponsor here, but I think I already know the answer, not a good idea. How do you propose to control the input pressure?

I currently have my unit hooked up to a cloths washer connection. I could dial it back there as well as a regulator on the out line to the sump.

 

[BIGG D]

I am not sure how well it will do under such a low pressure, I know this is not an answer to your questions but I run the Reef fanatic top of with a solenoid directly from my RODI and it has been great. I put $10 water alarm from HD right next to my sump just incase. Never any problems.

http://www.thefilterguys.biz/top-off_controller.htm

I had a solenoid go out on my whole house humidifier but it stopped working in the close position, I wonder if when they go south the nature of a solenoid would always error on the side of closed.

Just my opinion.
Ryan

This looks like a product you would use with a holding container full of water. How do you use it "directly" with your RODI unit??

 

[BIGG D]

rdlisby, measure your TDS at the ro membrane outlet. I think you'll be surprised. I used to operate my system that way and the TDS creep out of the RO membrane was really high - I went through DI resin in no time.

BIGG D, are you looking at restricting the outlet of the DI line to the tank, or the city water into the filter?

I would be restricting the pressure from the washer connection. It has a gate valve. There is also a small stop type valve on the out line itself.

 

[rdlisby]

I use the solenoid valve with the out put from my RODI water into the valve and then a line straight into my sump. The float valves control the power to the solenoid valve. It ends up being $140 for both pieces, but well worth it considering the number of times I turned the water line onto my tank and forgot about it.

P.s. on that link you don’t need the aqualifter, the pressure comes from your water supply. That way you can keep your pressure up to the RO unit.

 

[Buckeye Hydro]

I would be restricting the pressure from the washer connection. It has a gate valve. There is also a small stop type valve on the out line itself.

Not a good idea. Your system needs the pressure to work properly.

You might try filling a unpressurized storage container with DI water, and have that container munted up high on the wall on a heavy duty shelf. Then have a slow drip going from that container to your sump...

Russ

 

[BIGG D]

Not a good idea. Your system needs the pressure to work properly.

You might try filling a unpressurized storage container with DI water, and have that container munted up high on the wall on a heavy duty shelf. Then have a slow drip going from that container to your sump...

Russ

Yeah...the container is what i am trying to avoid. I really dont have room.I was trying to work directly with my RO unit.

 

[Buckeye Hydro]

OK - I'd stay away from restricting the feedwater or outflow from the system.

Remeber that you can build a DIY reservoir - think about 4" pvc pipe with end caps and some fittings - you might be able to mount that horizontally or vertically somewhere and hide it.

Russ

 

[BIGG D]

OK - I'd stay away from restricting the feedwater or outflow from the system.

Remeber that you can build a DIY reservoir - think about 4" pvc pipe with end caps and some fittings - you might be able to mount that horizontally or vertically somewhere and hide it.

Russ

Hmm...I think I just had a vision.
4" PVC pipe would look nice lining the wall of my sump room.

Wow...thats crazy.

But it could work!