watering big plants in small containers

i had to let my indoor garden veg 18 days longer under 80w flourescent and 2 t5's while my hps was being fixed.
now i have 3- 3 foot sativas (snowcap) and 3 -26 inch bushy little indicas (bubba kush) all in the same 26 inch wide x 50 inches in legnth and 7 foot high grow space in 3 gallon containers and i just began photoinducing them yesterday under 400w hps.

how often do i feed these bitches since all of the top canopy is filled in and the soil drys very fast under hid. ive been feeding them 2 cups h20 every other watering and fertalizing w/ fox farm nutes and granular solubles every other watering.
so my question is do i need to start watering every day and with fertilizer every other watering since theryre so big and theyre going to get bigger!? i didnt expect my ballast to break and the 3 gallon containers were all i could fit in my closet so i never planned on veging them so long.

and finally a similar question- i have 3 -18 to 20 inch plants that are 4 weeks into flowering and they are in 1 gallon containers. again do i need to water as soon as the soil is dry the next day because of the size?

obviously its better to under water than over water but i just want to hear some thoughts on this.

and for those interested my soil is fox farm ocean forrest and i use all thier fertiliazers
thx.

Consider that you might actually have to feed them less/water them more...

Since they're in a small container, but they're big plants they need lots of water. Water in a small container also dries out and evaporates quicker, leaving behind the nutrients. It's actually kind of counter intuitive, but you have less soil to store built up salts and fertilizers so you'll have to be careful to check the PH of runoff and not to overfeed.

So, my advice is to water more.

These days I really drench the soil so I get lots of runoff so there is les of a chance of salt buildup. Always test for proper PH.
How did you find such an old thread?

I have no idea! I usually just look at the new ones!

It popped up in front of me though. Maybe it was from the bottom of the page where it has related threads? I sometimes click on those.