plants dont seem to be feeding?

hi all ive looked everywhere on the site but cant find no answer? im currently on my 2nd grow so im pretty much still a newb!!

My problem is some of them are not drinking their feed? the pots have been wet for over a week now and they was feeding every 3rd day
my babies are in their 5-6 week flowering now, big buddha blue cheese(20ltr pots) and k2(11ltr pots)
they look really healthy!! got some lovely buds on them!!

ive been using....the temps are between 65-80 degrees, 80 lights on and 65-70 when off

1.2 tent
1 x 600 hps
1 x 400 hps
1 x 6" extractor fan temp controlled
1 x 4" intake

feed..
canna a&b 40ml-10ltrs
big bud 20ml-10ltrs
over drive 20ml-10ltrs
pk 9-18 2.5ml-10ltrs

any help on why their not drinking would be a massive help!!!

just added some pictures she looks healthy enough but i think i should have turned the flash off on the camera?

cheers all

Do you have a way of measuring the ppm of your nutrient mix? No other way we can interpret that feeding schedule, I'm afraid, unless someone else is using the exact same program. When a plant stops drinking in flowering it can mean a couple things that I know of.

1. The plant is nearly done. 2. The salt content of the soil has surpassed the mineral content in the plant and reverse osmosis will likely start at next feeding.

Couldn't be more specific without a pic and knowing the ppm of your nutrients.

hi bugeye thanks for the reply im not sure what you mean by ppm? soil im using canna pro plus if that helps in anyway?
i do like your idea of it maybe coz its nearly done as the main plant thats not feeding has been growing ahead of the rest even tho their all the same timed.

my lights r on at 11pm so il take picutres and if you tell me what ppm of the nutes to look for on the lable il get all in the info you want that helps.

You need to but a TDS/PPM pen and test your run off.

You can get one on the cheap. I got mine from amazon for $15.59.

TDS/PPM tells you the dissolved solids so you know the real concentration of what you are feeding, and in the case of testing run off (along with pH) you can tell how and what the plants are taking up. Along with that information you can tell if you can an undesired build up of things such as salts. Which can negatively effect plants.

hi thewifeofasmoker thanks for the reply, i dont have a ph pen but il go on ebay and order 1 straight away!! and test the levels
thanks for the info and il repost with the info