plumbing question on mixing station

[jkienzpac]

question on best way to plumb a mixing station to sump.

Sorry no diagrams...but easy question.

I have a 50g r/o and 50g salt mixing station in another room each have their own plumbing/pump (3/4" pvc) to go from my laundry room to attic and then down to the sump. (R/O line to go to top off reservoir tank under stand).

From the attic the pipes will drop 12 feet down then 90 degree turn then run horizontally about 6feet to the sump area. ( a basic- L).

So to the question...

1. At the bottom of the drop should I have a U-trap to ?slow down/smooth out the flow? Or would a 90 elbow work fine and then run horizontally to sump area.

2. Is it ok to leave salt water in these lines between water changes or should the pipes be drained dry or flushed (if any "low" points).

[csarkar001]

if you're worried about too much flow, ball valve to control/limit it would be best, instead of U-trap.

i can't imagine leaving the salt water sitting would be an issue.

[der_wille_zur_macht]

Agreed - pick a pump size and/or use valves to control flow rate. No need to "smooth" the flow in a case like this.

No need to drain the plumbing either IMHO - the water coming from the salt mixing tank will be (should be) sterile, and low nutrient, so not exactly an environment that would harbor undesirable growth.