I just started my plants on nutrients last week should I use nutrients every week or use plain water every other week
Depends on the nutrients. What you got?
Few deferent kinds but using foxfarms rn
If you’re using fox farms do their chart at half strength every week
K ty for the advice
Exactly what @GreenSnek stated, they also recommended a 30 day flush. FF trio can be notorious for salts and minerals building up I the root zone. Watering or feeding to run off helps prevent that some. Keep checking your run off numbers. They also make a flushing product called Sledgehammer 
If you need here is the link to FF feeding schedule as @GreenSnek said use schedule at half strength. The feeding schedule says twice a week which usually works out to every other time I water I feed with nutrients.
Happy Growing