line set for mini-split

[ghnl]

I am installing two Ramsond mini-split heat-A/C units. I should have ordered a 25' line set for one of the units (standard is 15' line set).

Is it acceptable to add 10' to the line set I have? If so, is there anything special to use for the copper tube (1/4" & 1/2") or can I use the copper tube sold by Lowes ("utility grade")?

 

[sneezer41]

there is a refrigeration grade tubing. you want clean. I would imagine a good flare is ok.