cf question

[wjr]

heys guys have got a 40 liter res witch i put in 20ml of both part a and b dutchmaster advance plus 120mls of add.27 dutchmaster and 20mls of rhizotonic now according to dutchmasters online calculator my cf should be sitting at 8 put when tested it was at 14 so i dumped some water out and added fresh water and got the cf down to 8 then 2 days later it is back upto 13???? growing in clayballs recirc system with tank water. could anyone explain what i am doing wrong ( ph is running at 5.8 but rises upto 6.8 everyday) any help would be much appeciated

[STONEDAJ69]

I think you'll find that your plants are drinking some of the water

[wjr]

thanks for the quick reply mate ..this happened the first day i put the plants into the system there only like 4 inches high then the cf went back up the next day i didnt think they would throw it out so quick

[allhailthebud]

hey wjr,

 

If you find that the next day after testing your EC/CF it has raised, this means your plants are drinking more water then nutrients. So dilute your nutrient solution.

 

The idea is to try and get your plants uptaking an even mix of water/nutes. Top up your res and measure it again the next day, If the Cf is reading higher then the day before, then your plants are uptaking more water then nutrients. So dilute your solution.

 

Again the next day do the same, untill your find your EC/Cf is staying the same (day by day basis), meaning your plants are uptaking an even water/nute mix. As the plants grow and get bigger, they'll start uptaking more nutrients then water, so you'll find your solution will lower in Cf, therfor you need to add more nutrients as plants are drinking more nutes then water.

 

Your plants are very young (4" tall) id back off the nute solution untill your find they are uptaking even ammounts of water/nutes.

Peace

 

EDIT - your PH is rising as its a recirc setup, excess nute solution is travelling back to the res, as your plants drink more water the nute strength gets higher increasing the PH level, to my knowledge

Edited July 1, 2011 by allhailthebud

[wjr]

thanks heaps mate .that all makes perfect sense