RO/DI maximum safe supply line run

[Lohr]

Good morning reefers

I am planning on installing a BRS 5 to 7 stage RO/DI. In the area I'm placing it I do not have a current water supply within a reasonable distance. I want to install in near a sink in my garage. My total tank volume is low at approx 100 gallons so my top off tank where i plan to run the RO water to will be a 40gallon breeder. I want to run a water supply line from the RO out to the top off tank, so i can directly fill into the tank and avoid stairs and 5 gallon buckets. If i were to run a supply line it would be vertical 6 feet, horizontal 21 feet then another 4 vertical to the top off. I have not measured my pressure but would like to avoid running a booster pump if possible but if needs be I will. This leads me to 3 primary questions.
1. Will this be possible to make an approx 31 foot run with likely 3 or 4 90's and still get efficient RO water?
2. With 31 foot of water, would i want to put a bleed off valve at the lowest point in the system to not allow the RO/DI water to be stagnant in the line between top off additions.
3. What is the best way to mitigate biofilm in the long water supply run if its sets empty for a while?

 

[mfinn]

I have no idea if your house water pressure would move water that far ( I doubt it will without a pressure pump), and it seems to me you would need to run a shutoff switch/float at the 40 gallon breeder tank. That might present problems.
I would run the rodi into a container in the garage and then use a pump to move the water to the top off container. As long as both containers were the same size, there would be less chance of a spill. But not completely.

 

[Lohr]

I was planning on just filling the 40 ATO once a month or so as compared to having a float. I am almost certain i will need a booster pump.

 

[fishguy242]

Would definitely need a booster pump for that kind of run , house pressure will not be enough 90lbs is what i think you would need .
also agree bad things can happen with a top off direct to tank , never can trust a auto shut off switch /float/ato
JMO N JME...

3. What is the best way to mitigate biofilm in the long water supply run if its sets empty for a while?
Keep all lines and membrane full always ,shut off valve at all 3 points