Skip on the canister filter, unless you are prepared to do a lot of work to avoid them becoming a nitrate factory.
1.) Up your water changes in frequency, and possibly in size (say 10% total volume per change).
2.) Get your new bulbs
3.) Get new testkits and write on the top when you received them
4.) Set up a tracking method so you can track your parameters over a long period of time. A notebook works, so does an excel sheet.
5.) Run new carbon & GFO (phosban, phoslock, etc) and change them both frequently. HOWEVER when using GFO do not go right to the label's full dose immediately, work up to it.
6.) Patience, it will pass!
