HELP! Raising and lowering my DWC ph lvls?

i was wondering if its ok to use aquarium ph up and ph down?
if so how much should i use for just over 30 litres?
i need to know my ph is at about 6.0 - 6.1
my clones need to get in my brand spankin tub

I was just reading in the faq for ph check it out..

Straight from the Grow Faq.
Raising hydroponic pH : (to make it more alkaline)

In hydroponics: use potassium silicate, provides silicon at an effective doseage.
In bioponics/hydro-organics: add small amounts of sodium bicarbonate or lime.

Lowering hydroponic pH : (to make it more acidic)

In hydroponics: use nitric acid during vegetative; phosphoric acid during flowering.

thanks for the advise man