Servus Mate,
Just finished my actual run, which was ment to run as SOG.. didn't work..nevermind.. i also use a coco, perlite mix. I hd them in 3.6l pots and the indica dominant plants reached about 1m.. so you maybe wanna think again about pot size.. i wouldn't suggest Sativas for SOG.. it's difficult to predict the stretch..
Good Luck Mate, have a good one🤘