Looking at that link, all it looks like needs to be done is put eyebolts in the ceiling or something over the tank, and put those betwixt the hood and the support.
I think adjusting the wingnuts just sets the amount of tension so it compensates for the weight of the light/reflector. The only time you should have to do this is when you set it up, or after you change bulbs or something, and maybe an occasional tweaking.
After that, you should be able to just push/pull the reflector to adjust it's height.
I'm pretty sure the tension just serves to help cancel out the weight of the hood/reflector.
Disclaimer: I don't have this nor have I seen it in person, that's just the best I can figure by looking at the linky