ph stays to low

[fasts102376]

hello all i'm doing a dwc setup in a 6'8 by 6'8 by 6'3 room with a 1000w hps.. i'm in the 4th week of flowering useing G.H nutes at 1/2 str.

everytime i set my ph a 5.9 the next day it's down in the 4's is there a reason why my ph keep droping?

to give you a little rundown
im useing 5g buckets and the room temps stay around 80 to 85 and the hummidity(sp) stays around 45 to 57.

if anybodys had this problem can you help me..

if you need more imfo let me know..

thanks

 

[Smokin Moose]

First up, why are you only running half strength ferts this far into flowering, under a 1000W HID? I would be using full strength IMO.
Do you notice any nutes "falling" out (ie salt crystals on the bottom of your pot?
What is the ph of your water without ferts?
As a fast growing plant uses nutrients, it leaves behind the unwanted ones, sulphates being one (sulphur), which makes your water more acidic. This is one of the things to need to watch with hydro.

 

[Urdedpal]

You can't use GH nutes at full strengh Moose. Its just too strong for mj plants. Going over 65% normally means trouble. 1100 ppm is normally bout as far I go unless I boost with epsom salts. The epsom salts will raise the ppm another 200 ppm or so with out the burning.(not sure how useful it is though since flora bloom is derived from magnesium sulfate)
Now back to ph, when ph becomes unstable and drops like this I normally fix this with a nute water change. Too many reactions are going on and I doubt it will be posible to stablize it. I suffered this my first and 3rd year growing but waterchanges always fix this for me in the past.

 

[Stix]

how many plants do you have and how many gallons is your resevoir?

 

[paperbag]

Whats the bucket temps?

Ph could be dropping fast because that room is a lil hot at 85.. when the water evaporates, your ph drops, coupled with the plants drinking it.. loss due to transpiration etc.

All you can do is monitor your humidity/temps, keep those 5gal buckets cool, and topped up w/ water. Adjust the ph daily, i know that its a pain to have to measure and adjust daily.. but its the price u pay sometimes.

 

[Smokin Moose]

You can't use GH nutes at full strengh Moose. Its just too strong for mj plants. Going over 65% normally means trouble. 1100 ppm is normally bout as far I go unless I boost with epsom salts. The epsom salts will raise the ppm another 200 ppm or so with out the burning.(not sure how useful it is though since flora bloom is derived from magnesium sulfate)

Urdedpal, the youngsters are always saying you and I are the experts, but the amazing thing about cannabis is that you never know it all lol. I just learned something very important about GH dilution. I am on a fast learnig curve with hydro, as I have always grown organic, so following these threads is far from mundane,
Youngsters take note. You can teach an old dog new tricks.

 

[fasts102376]

thanks all for the great advise if i keep it toped off with plain water it's saying stable.


thanks again