more waterchanges, less feeding and no driftwood. i only feed my fish 3 times a week. i have 30 africans, 6 loaches, 3 plecos a catfish and a peacock eel in my 150. i have 3 pieces of driftwood and do 50% waterchanges every other week. my pH is 8.0 and i only have a handful of CC in my filter. You should remove the driftwood and cut back til your pH is where you want it.
looks like you got a cascade canister filter. same as mine. fill the last drawer full of CC and keep it clean. they are bad about holding crap and the longer it stayes in there, it rots and lowers your pH. maybe add some limestone rocks or tufa rock for decor. both help raise your pH