Polyethylene or polypropylene pipes for ro/di water ?

[jake37]

We want to do some plumbing for ro/di water behind the house in a wall to move water from the basement to the 2nd floor aquarium. The distance will be approx 20 ft vertical and 200 ft horizontal.

I've been doing a lot of searching on this topic the past month and keep finding conflicting discussions about which material is safe for ro/di water. Some claim cpvc is safe other pex-b; but then i find information that suggest that they will both leach.

What i cannot figure out is if both polypropylene and polyethylene are equally safe and which would work better for about 200 ft of behind the wall piping. About the most i've discovered is that polyethylene will be more of a flexible tube and you can buy stiff polypropylene pipes but not sure that matters.

(we suspect pvdf is best but the estimate to use that stuff is around $80,000 while using pp or pe would be approx $3,000....

 

[exnisstech]

I would think anything safe for drinking water and would choose which is easier to work with.

 

[jake37]

I would think anything safe for drinking water and would choose which is easier to work with.

Well copper and pvc are safe to drink but they both leach....

 

[Gtinnel]

The standard rodi tubing is polyethylene so if it were me that is what I would go with.

 

[exnisstech]

Well copper and pvc are safe to drink but they both leach....

All of my tank plumbing is pvc and has been for years. I just did an ICP test recently with good results so I'm not sure what they are leaching? From all the biuld threads I have seen everyone uses pvc so. I'm confused, which is nothing new.

 

[KStatefan]

I would just use 3/8" john guest pe tubing. Upsizing due to 200 ft run.

 

[jake37]

All of my tank plumbing is pvc and has been for years. I just did an ICP test recently with good results so I'm not sure what they are leaching? From all the biuld threads I have seen everyone uses pvc so. I'm confused, which is nothing new.

It was based off of articles like this one:
aspe.org/pipeline/what-is-the-best-material-for-reverse-osmosis-water-for-hospital-equipment/
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For any system that includes deionization, Schedule 80 PVC is not recommended. The aggressive nature of the DI water will extract additives from the PVC, weakening the piping structure and contaminating the high-purity water. However, for single-stage RO systems, PVC is acceptable.
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This is one of about 8 or 9 references I saw to pvc leaching; but i don't know factually if it is a big issue. I realize most tank plumbing is pvc but not sure how pure the water is once it is in the aquarium. My concern is that for pipes behind the wall i don't want to have to rip out walls if pipes/tubes need to be replaced.

 

[AviM]

Regarding the running of plumbing behind walls: For RO tubing, or other flexible tubing, you can run a larger hard pipe with sweeping 90’s or 45’s that the tubing can then be pushed (or pulled) through. It goes without saying that there should be zero fittings run inside the larger pipe. Then the tubing can be replaced or removed easily. If the hard pipe is large enough, you could run more than one tube, or even run direct-bury rated wiring with the tubing. That’s not typically done, but can be done safely.

 

[jake37]

Regarding the running of plumbing behind walls: For RO tubing, or other flexible tubing, you can run a larger hard pipe with sweeping 90’s or 45’s that the tubing can then be pushed (or pulled) through. It goes without saying that there should be zero fittings run inside the larger pipe. Then the tubing can be replaced or removed easily. If the hard pipe is large enough, you could run more than one tube, or even run direct-bury rated wiring with the tubing. That’s not typically done, but can be done safely.

Yea we were considering that but i can't find food grade tubing that is 3/4 or 1 inch (most of the stuff that large i find is intended for irrigation; also we've come to the understanding that PEX is basically PE that is in pipe form and we are thinking we should use that...