Hi, you will need a PH which is between 5.5 - 6.5... if the ph is too high or too low you can Ph Up + Ph Down.

I dont use any of these, I have just a ph tester... I did some tests myself...

I checked normal tap water & the ph was 8. So I boiled the kettle & let the water sit on top of the fridge for 12hrs, added nutes & checked the ph & it was a 6.5... this is average so its good for me.