what amp fuse is popin ? prob. a 15 amp. huh ?
you need to see what all is on that given circut . if at all possible maybe you can have someone upgrade your panel n hopefuly get it on a 20 amp. fuse/breaker .

when i added the extra 1000w. i had a friend run a small subpanel and a 240 line just for my room and bought a greenair controller/timer that turns the 1- 240v line into 4-110 v. outlets each capable of running 1000w. each .
now both my 1000's and both my blowers/via. a fan controller are all run off the same timer w/ an outlet to spare incase w/ wanna expand in the future .

there's prob. no cheap / safe way around your prob. i'm blessed w/ lotsa friends in the hvac / elect. industries + i have an awsome support group . will it atleast support just your 1000w.? might havta live w/o the 400 mh. for this grow ?
heres a pic. of my controller , fan control etc...
peace n be safe
your cuz crispi