Thanks for all the replies, looks like I just need to add some CaCl and a little acid to lower the pH.
In general, yes, but it depends.
If it makes any difference the recipe is pretty simple with 9.5lbs of pilsner malt and 0.5lb of caramel/crystal 10 for a 6 gallon batch, also it will be brewed using BIAB.
I assume that means all the water goes in at once?
I am thinking 1g gypsum, 4g CaCl2 and 2ml lactic acid. According to ez water this should give me 42 Ca, 61 Cl, 18 SO4 with a pH of 5.51
The molecular weight of calcium chloride is 110.98 mg/mmol so the calcium ion concentration from 4 g (4000 mg) in 6 gal is (4000/110.98)/(6*3.785) = 1.587 mmol/L. The molecular weight of calcium is 40 mg/mmol so we have 63.5 mg/L from the calcium chloride alone. If we assume the spreadsheet uses the molecular weight of the dihydrate then we would have 48 mg/L from the calcium chloride alone so there is something wrong with the spreadsheet calculation.
I won't say that you must not have sulfate in a Bohemian Pils but I will say that you will probably like the result better without it. I'd suggest you brew it for the first time without any and then experimentally add some in the glass while tasting it and if you like the result then by all means use it in the future.
Now as to pH and acid: were you to use a relatively acidic base malt, such as Weyermann's regular pils malt and a dark crystal such as their 60L in the amounts you have specified with the amounts of calcium salts you have specidfied, you hit a mash pH of close to 5.5 without any acid. OTOH if you use Weyermann's floor malted pils with 10L crystal you'd have a mash pH closer to 5.75 and would need 3.3 mL lactic acid or, better, a quarter pound (2.4%) sauermalz.
You'll probably use something more like the normal malt with a reasonably light crystal from which you could expect a mash pH of around 5.5 but note that all these numbers I've given rely on the 3.7 mEq/L calcium to provide 12 mEq protons. If you reduce the calcium, and I'd suggest you do to, say, 2 grams calcium chloride only, then you'd need 1.4 mL lactic acid or 1% (1.6 Oz = 47 grams) sauermalz.