RO/DI system designs for filling fresh water and salt mixing

[BobinCovington]

I am thinking through my RO/DI water system and looking for some feedback. I have the RO unit but I want to run water to three places from that single water supply.

1 Auto fill my 25 gallon freshwater tank and then shut off with a float switch (for top off via osmolator to the sump)

2 Fill my 25 gallon salt mix for batches by turning on a valve and having a mechanical float switch shut it off when full (then physically shut off valve until next batch)

3 Run freshwater to a small sink on my workbench to rinse test kit vials and labware.

I am a little concerned about the slip in guest fittings popping loose under pressure and flooding my garage, so I was thinking the float switch should shut off the supply upstream of the RO DI filter unit. I also don't really trust the solenoid to control the water in to the sump

I have a 3/4" hose bib that will attach to a 3 way splitter with each line separately able to turn off-on. I could just have those black plastic mechanical float switches in each water tank and physically turn the line off when tanks are both full. Then that just leaves the line to the sink under pressure all the time.

simple and reliable are my goals. I'd welcome any advice or any current setups that work well and anything to watch out for.

you can see the RO system on the right side of the sump bench and the reservoirs for salt and fresh water or located to the right of the bench

...also I have some pictures of the new stand and the elos tank in my thread under tank design for those who have been interested (link below)

 

[Scooterman]

One thing good about making all of your top off water at once is you reduce Creep. When I start my Ro/Di the TDS level starts about 25 before the DI then slowly drops to about 1, then It passes through the DI & 0 out. Don't know how much of that actually gets into the water but reducing the amount of frequent start & stops is much better for the unit to say the least.
I would upgrade your unit to a second Ro membrane, the Dual 75GPD membranes are the most efficient way to make RO/DI & get more out, comparing to a 150gpd unit.
I wouldn't worry about the guest fittings, they work just like the Chinese handcuffs, the more pressure you pull the tighter they get, simple concept that works well, also if your using float switches to shut off the water, you could easily put a supply valve to turn off completely when not needed.

 

[DonW]

Bob,

JG fitting are safe probably one of the safest fitting made. You can split your rodi output three ways with something like this.

One side going to a float valve in your FW tank. One going to a float valve in your SW tank and the other going to a regular valve for your sink. You can add little shut off valves where you like. You will have to get an asov otherwise your rodi waste line will run forever.

Don