looks like new tank cloudyness to me which will go away in time....how old are the tanks? when you say you changed the filters, does that mean you threw out the old media? (thats where the bacteria is for your completed cycle) if you did, it will throw your tank back to the cycle process

the cartridges dont need to be changed unless they are totally falling apart which can take 6 months or so....the carbon is only good for 2-3 weeks so after that time, id cut a slit in your cartridge and dump the carbon out....