<span class="link_user">@Mia_BIOTABS</span>, You should start measuring your daily light intake (DLI) at canopy - get photone on your phone, it's life-changing. This grow is lanky and thin because it hasn't had enough lights and you haven't really trained it. No judgment from me by the way, we're all learning.
I also run SF-1000 and it's more than enough for a 19L plant (see my diaries) if you get the distance from plant and intensity right -- just tune everything towards the DLI.
<span class="link_user">@Robtatro</span>, can I recommend in future watering a bit further out from the stem (i.e., no wet soil at the stem base). It forces the roots to go looking more horizontally which creates more stability and a better plant structure over all. Or at least, that's the broscience I subscribe to and my plants seem to benefit from it.
<span class="link_user">@Loran11144</span>, I did indeed top twice at days 22 and 31 :) Definitely learned the "don't top autos" wisdom doesn't seem to apply to the modern auto genetics I've been running.