Fresh res PH adjustments

[Hashleyz]

Hi all, I did my first res change yesterday in the dwcs, the water went in at 5.8, checked this morning and it was back upto 7.5 so I lowered it back to 5.8. 1 hour later its back upto 6.7. 
 

Clay pebbles were soaked and rinsed twice in 5.5 over 24 hours.

 

Is it possible that I am airating the water too vigorously?
 

currntly running at 0.6ec with:

 

dutch pro silica - 0.1ml p/l

Silver bullet - 1ml p/l

dutch pro grow a+b 0.2ml p/l of each

dutch pro grow PH down
 

I don’t mind keep lowering it but is it normal for it to rapidly rise so fast? How often do you dwc guys have to adjust PH? 
 

Tia 

[Geo]

Its most likely your water,if you have hard water it will have a high buffering capacity (KH or carbonate hardness) which resists changes to PH. The addition of acid will eventually reduce the buffer and the ph will drop like a stone so be careful not to overshoot. When you know how much to add in veg and bloom jot ii down for future reference. The dutch pro grow ph down is nitric acid, the bloom ph down is phosphoric acid so they are not the same.

 

[zen-ken]

How big are the girls ?  Stage ? 
 

my pH climbs like this in veg if I don’t feed enough and does the opposite in flower when feeding too much or incorrectly.

 

 

[Hashleyz]

@Geo @zen-ken

 

I sorted it by raising my EC to 0.8, the extra nutrients helped to stabilise the PH and it’s running like clockwork now. 
 

the trouble I had was that my tap water had an EC of 0.5/0.6 and I was trying to keep it at 0.6 because the girls are only 2 weeks old but it wasn’t enough to stop the PH from rocketing back up to 7.5. 
 

PH has been slowly climbing over the last 4 days since I added more nutes and was at 6.0 yesterday so I’ll either PH down them either today or tomorrow. 
 

Girls are growing like mad now that it’s all dialled in correctly, and the roots are growing in front of my eyes just about!