400 GPD Reverse Osmosis tubing size?

[zhengjdc]

Hi All, not new to the forum but couldn't even remember my old account to this forum thus use my facebook as a new way of registering.

Replaced my old 50gpd tank unit with a 400GPD tankless unit from Aliexpress, and the input tubing is 3/8 with a Chinese standard 1/2 inch T-valve(I assume it's 1/2) and since it won't fit our Canadian feed line, I have to buy a 1/4 to 3/8 tubing conversion kit in order to make it working with the existing 1/4 t-valve on my water feed line.

Now this concerns me as there is now a small portion of the feeding tube being 1/4 instead of the 3/8 tubing coming with the kit, and will it become the bottle neck of the system? It's a 400GPD system thus water flow is 8 times more I assume?

The pump is located right before the membrane, and the output, and wasteline from the membrane are both 1/4, and it's the only feeding line being 3/8 inch.

So far it seems to be producing nice 400GPD flow though I don't have a good measuring method, but you know for an OCD person like myself, I am still a bit worried.

Solution 1: leave it as is?

Solution 2: getting another 1/4 t-valve, using both 1/4 t-valves and buy a dual 1/4 to 3/8 tubing y-splitter, thus, doubling the 1/4 tubing bandwidth will thus no longer bottleneck 3/8 rest of the feeding tubing?

 

[blaxsun]

My experience has been that the bottleneck is the membrane itself, as there's just only so much water that can be produced by the unit itself (which is just a trickle in realtime on my 50 GPD system).

I have a sneaky suspicion that even if you upgraded the tubing to a pair of 1/4" lines that you might not see much noticeable difference.

The biggest difference I made with my system was adding a pressurized storage tank so that it holds roughly 4 gallons of RO at any given time.