Do you gotta fill in the cartridge fully with DMT vape juice, cant you just use a little bit?

I bought this 2nd hand GeekVape device

Its the first time trying vaping, I just burned 2 of my atomizers, only 1 is left

I wonder was the problem that I havent poured in 3gr-s of liquid? But instead I made just 0.7grs?

I only had 0.15gr DMT, + I added 0.45gr 50/50 PG/VG juice.. I couldnt even make that much vape juice, should I extract more DMT first then make the vape juice?