Problem with Reveg, Ph changes drastically everyday!!

I just had my first grow and it turned out very well yeilding about 12 oz of bud. White Widow, Durban Poison and Island Lady using FloraNova. I am trying to reveg. I changed the water and put in nutrients for vegetative growth. Turned the lights to 24/7.

I am trying to reveg 1 white widow and 1 durban poison. The white widow is turning yellow (the stalk and everything) The durban poison seems to be hanging in there. Anyways, I am wondering if the white widow is dying and causing the ph to drop super fast. I have been revegging for 2 weeks now and the white widow is not coming around. The ph changes from 6.5 to about 3.8 in one day. Could the dying plant be releasing some toxins in the water causing the change? It is in a 36 gallon bubbler. I change the water completely and the same thing happens. I just don't want to kill the durban. I keep adjusting the ph but it changes back in one day. Help Please!!!

Ph is still dropping from 6.5 to 3.8 in 1 day. Can anyone tell me if the white widow plant that is probably dying is causing this???? Has anyone experienced this?????? Its not the water and its not the nutrients because I have been using these for a few months. Only during Reveg is it doing this...

For any interested, the dying plant was causing the ph to drop. I pulled the plant and its roots and now the water stays at a constant ph of 6.0. I guess if anyone ever runs into this problem I can be the expert since no one else seemed to know around here....

I must be talking to myself..... Now the water is changing in one day with the durban poison. What the fuc*!!! The ph drops to about 3.8 in 1 day!! I guess that means my durban poison is dying too. Any input from anyone?

type in reveg in the search function, revegging only works maybe 50% of the time, it seems like I have read "zandor" addressing the ph issue somewhere, click on his name and look up his old posts.