Meyer Lemon Trees

Any ideas on keeping a 6' meyer lemon tree spending the winter in my living room healthy? It gets spider mites and sometimes ants migrate from outside and move in the pot. Sometimes when we have mild days I drag it out on my south facing deck and spray it off but it's gotten so large and heavy I have to be really motivated to get it out there. The lemons it grows are delicious and I have made quite a few lemon merinuge pies. Mumm! Good!