Sounds about right, just go easy on the light intensity, IMEthey get sunburn super easy and in seedlings thats a death sentence, Do post up pictures of your little seedlings when they peek up, love me some cacti seedlings!
I need to order some more Trichocereus seeds to so all I have atm is Lophophora Williamsii and Difussa. Been a while since i've had seedling. might have to find a good source of Trichocereus seed, working on expanding my Pereskiopsis Spathulata stock and plan to graft most of the Lophophora seedling... thinking a winter project though.