Light stress?

if there was no cleaner or other contaminant in the water you added, i'd wager it's too much light. too much light will cause droop as the plant shuts down to prevent damagingn itself. Unless something else is left out of the provided info. They look quite lush. i'd start reducing fertilizer concentration. It's good to get those leaves full of stored nutrtion,but at some point you have to switch gears to maintaining levels in the plant, not increasing. When foliage gets dark, it's time to dial back a bit.