Copper Sulfate and Lateral lines

[Beap52 1,834]

Part of our kid's lateral field became plugged with tree roots.  About three years ago the line was cleaned and/or sections replaced so it's now fully functioning.  In addition most of the trees (it was essentially a woods after 45 years of growth) were removed.  There are a couple of large oak trees in the vicinity and I wonder if copper sulfate poured into the distribution box could reduce/prevent roots clogging the field lines?  I've read that folks pour a couple pounds of copper sulfate into the toilet at a rate of two pounds per 300 gallons of septic tank.  I'm thinking a mixing a couple pounds of copper sulfate with 5 gallons of water and pouring in distribution box that will allow it to flow straightway into the lateral lines. This way it won't have an effect on septic tank.  Suggestions? Experience with this type of situation?  Thanks, Phil

[JoeM 9,375]

1 hour ago, Beap52 said:

pouring in distribution box that will allow it to flow straightway into the lateral lines

yes, I do that treatment yearly. 

I have a vent down stream of the tank and pour the crystals, about a pound,  in there and put a hose into the vent and let it run for a minute or two

No issues for the last ten years.