Ph is drifting to 5.0

The last few days I have been noticing my ph go from like 5.9 to 5.0 in my res. The tank is 40 gal and they eat like 10 gal a day on the flower cycle at the moment. I have been just topping it off and adding a little cal/mag cus my tap water is at 120ppm (its well water).
I have been changing my res every 7 to 10 days so im not sure if it salt buld up or what. Also my ppm I try to keep at 380 or so not much over 400 if I can help it. They start to burn any higher.
My nutes are GH.
usally the ph goes up not down what do ya think?

root rot maybes

Plants look good. So hard to believe that.

well i had a similar issue years ago that was the issue over feeding will do the same
if thats the case check for some sludge on the roots

if there is dose with cannazyme or H2o2 is there ppm drift and which way

motul123 said:

The last few days I have been noticing my ph go from like 5.9 to 5.0 in my res. The tank is 40 gal and they eat like 10 gal a day on the flower cycle at the moment. I have been just topping it off and adding a little cal/mag cus my tap water is at 120ppm (its well water).
I have been changing my res every 7 to 10 days so im not sure if it salt buld up or what. Also my ppm I try to keep at 380 or so not much over 400 if I can help it. They start to burn any higher.
My nutes are GH.
usally the ph goes up not down what do ya think?

Click to expand...

Hello motul123.....

I use GH nutes and I am going through over 7 gallons a day.....If I set my barrel of nutes at 5.9..my buckets will go down to around 5.0....so I rise my barrel up to 6.1 to 6.2 and through out the week it will rise to 6.7 to 6.8 and my buckets will be around 6.0 give or take a point or two.......So I adjust my barrel to make up for the ph drop in my buckets....

If my higher PH in my barrel doesn't fix the ph in my buckets then I would worry about something not being right.....I run alot higher PPM than you are but I am DWC not a AERO set up...right now I am at 1230ppm down from 1400ppm......anyway it is normal for my ph to be a lot lower in my buckets as long as I can adjust it and get it to move up where I want it... with out it keep going down......nitro...

I just flushed and changed the res,, took out a hugh mass of roots in the tank. They looked ok nice and white with a little tan from the bloom complex I use but no slime or green mess.
I am re nuting and at the moment the ph is at 6.4 and ppm is 401. Ill start to bring the ph down to 5.9 and see it stays there. Im sure it will drift a bit till it stablizes.