RO Unit float shut off good water, but bad water continues?

[JackBlasto]

Could someone explain if I'm doing something wrong here. Is the waste water supposed to stop (along with the good water) when the float is activated? I have a float stopping the good RO water but the waste water continues to flow. This seems like the mechanics are similar to me holding the end of the good RO water which would build up extreme pressure if the water continues to flow through the unit. How is this ok to do? Wouldn't it break something building up pressure like that?

Do I have the float and shutoff valve hooked up wrong? It checks with the instruction but something seems wrong. Any advice? Thanks.

 

[Phranque]

It's not at all unusual for the unti to run for a few after the filtered water is shut off, especially if you have a DI canister.... it's just building up some pressure before activating the cut-off. As long as all the fittngs are connected properly, and it's not leaking you're fine.
Now, personally, I don't like using an RODI system like that.... it's very inefficient. RO membranes work at their optimum when they are allowed to run for a little while. Hooking a top-off directly to the RODI system has it constantly starting and stopping, which anyone with an inline TDS meter will be able to tell you, when the unit first comes on, the TDS tends to be rather high and then slowly works it's way down as the unit runs for a couple of minutes.
Personally, I'd keep a jug or bucket of water and either run something like a BRS top-off pump or gravity feed your water to the top-off.

 

[fort384]

You have to install an auto shut off valve along with the float valve:


Installing an Auto Shut Off Valve - Instructions - Bulk Reef Supply

 

[fort384]

It's not at all unusual for the unti to run for a few after the filtered water is shut off, especially if you have a DI canister.... it's just building up some pressure before activating the cut-off. As long as all the fittngs are connected properly, and it's not leaking you're fine.
Now, personally, I don't like using an RODI system like that.... it's very inefficient. RO membranes work at their optimum when they are allowed to run for a little while. Hooking a top-off directly to the RODI system has it constantly starting and stopping, which anyone with an inline TDS meter will be able to tell you, when the unit first comes on, the TDS tends to be rather high and then slowly works it's way down as the unit runs for a couple of minutes.
Personally, I'd keep a jug or bucket of water and either run something like a BRS top-off pump or gravity feed your water to the top-off.

I agree - much more efficient to just fill a container once a week, and then top off from that.