Quote Originally Posted by Bedtimeforbonzo
Thx Stinky ok i flushed 1 plant last nite with tap water that came out around 9 and the run off came out 7.0. Today I flushed a plant with 7.0 water and the run off was around 6.8....When i started these plants they were in some crappy potting soil, But i recently changed to Sunshine mix wich has dolomite lime wich i think wont allow the ph to go over 7.0 is that correct? So If my ph drops a few points going through the soil should i just start watering and feeding with around a 6.7? So the run off will be around 6.5?.
Okay it sounds like you've brought your soil up to about 6.5. Now just keep on top of watering with fert solution that is 6.7-7 and monitoring the runoff to ensure it stays below 6.9.
The lime is actually a ph up type buffer; calcium carbonate neutralizes acid and is meant to keep pH from dropping too low.