i hear it is a lot harder to flush time released nutes out...i hear if your using time released nutes you should switch to regular nutes the last month so u dont have to worry about flushing them...
in my personal opinion it isnt worth the extra 6 hours for the amount of difference it makes.... i havent seen much difference in the two so i rather just save on that electricity...also you are supposed to pick either 18-6 or 24-0 for the first approx. month then when u want to switch to...
basically it comes down to more wattage, better quality. if it is out of the 5X5 area it is getting less than optimal wattage... take this for example...car audio amps online are 500 watts rms and another website will advertise the same exact amp as 2000 watts peak because it "works" up to 2000...
flushing is allowing approximatly 3X the size of the pot size into it to flush the ferts and nutes...so if ur growing in 1 gallon pots then u flush with 3 gallons of ph balanced water... it is done 2 weeks before harvest in an attempt to make the plant use its stored ferts up and have a less...