droopy leaves

this is my first time to grow indoor im doing one plant it is about 4 foot tall its in the 3rd week of flowering i have it on 12 and 12 the buds are starting to look nice but i have a problem with sagging leaves i have co2 i have a fan all the leaves are green its just the leaves are just drooping ..............am i overwatering how often should I water its in a 5 gal pot and im using fox farm ........what should i try to make the leaves look healthier
..............................plz help

water on every 3-4 day-lift your pot up, if its heavy dont do it, if its light and un watered for example 3-5 days, then its exelent to water it

I would water once a week but when you do water flush the plant at the same time.This may sound odd but i was given this way of growing in amsterdam and my yeild have improved alot.Start of by takeing the plants to the bath room it can only be done if you are growing a max of 6 plants.Take 3 at a time and make a big batch of water ph of 5.0/5.5 and soak the plants through with this this will get rid of any old nutrients and most important any salt build ups.put at least 6 ltr of this water through the plants then leave them till the water dissapates.While you are doing this make a fresh batch of nutrients up.Once the plants have run of then add the mix that you have just made then wait for them to become dryer so there is not much run off.Then bang them back under the lights and re~peat the process 1 week later.By doing this you are getting rid of all the old nutrients and salts that all plants produce.Then by adding the new made nutrients after is thatthe plants are getting all the nutrients they need and all the ph is bang on the plants love it.