Ok, so to make sure i understand correctly.
The grain effects the PH of the wort so we need to consider that before adding anything. As i am using RO water, i select that as my default water in Brewfather. I think go to the water selection and choose the type of style that i am making and then that will add the salts etc that i need to add.
If the PH is over 5.6, i need to use either acidulated meal that i can add the to the grain bill or i can use phosphoric or lactic acid to the mash for example and that will bring the PH down, that correct ?
I am still learning about PH to be honest, should i be shooting for in the middle of 5.2 and 5.6 or is it style dependant ? When would i be aiming for 5.6 as opposed to 5.2 ?
Thankyou for coming back to me, appreciate it
What MHB said and some further questions.
What style are you trying to brew?
What was the resulting predicted Calcium (Ca) concentration (ppm) from the salt additions recommended by the water profile? This can also affect the mash pH (higher concentration, lower pH), is important for yeast health in fermentation, and as indicated in the article MHB attached will affect the pH of the final beer. In my view, ensuring sufficient Ca concerntration is probably more important than calculated mash pH at your stage of brewing.
As indicated in the document MHB posted, pH is important for the performance of the various enzymes in the mash, but ultimately it is a compromise across a range of variables. A range of 5.2 to 5.5 (at mash temperature) is probably the best compromise for most styles. 5.6 will probably make good beer (given at the homebrew level you are not particularly worried about maximising extract, etc).
Remember that the recipe calculator is only an estimate. With respect to adjustment, if you are worried about pH I would recommend you get a pH meter or pH test strips and measure actual mash pH before making any adjustments. If you do need to make adjustments, do it incrementally (start with half, measure the result, etc) and roughly scale the expected quantity based on the difference between the calculated and actual pH. You also need to know how your pH meter compensates for temperature (pH decreases with temperature), and the reference temperatures assumed in the recipe calculator. For example a pH of 5.6 at room temperature could correspond to ~5.3 at mash temperature.
Hope this makes sense, as you can appreciate it is a fairly complex subject and probably fairly low down on the list of things to worry about/master if you are just starting out.