Well I still don't understand how to get 150ppm of alkalinity w/o 5 tsp of CaCO3. How much lime adds approx. 150ppm? Is it liquid or powder (CaOH?). I did download "Bru'n Water" once but I found it mind-blowingly complicated. I'm making 5 or 10 gallon batches of beer not running a microbrewery. I didn't think putting all that effort into water would make my beer any better. My water is pretty much very soft as I used bottled water, so in some beers I want to up the Ca, alkalinity and sometimes the sulfate. I get gypsum, but again am confused about alkalinity.
Your finding on Bru'n Water is common for those who spend a minute or two looking at it. Far too many inputs and pages. As all the users who took the couple of more minutes to learn, once you have the program set up for your water source, it is quite easy and requires no more input than any other program out there. Unfortunately, there isn't an EZ solution to brewing water chemistry. To adjust your brewing water effectively, you actually need to have either knowledge or have something like Bru'n Water that tries to look over your shoulder and keep you from screwing up.
The quoted message hits on the most important aspect of brewing water chemistry. Its not hardness or softness of the brewing water, its alkalinity. Learning how to properly adjust brewing water alkalinity should be a brewer's primary concern. Keeping the overall mineralization of the brewing water at moderate to low level is the secondary goal. Nate correctly points out in his message above that its unlikely that brewing water will need more than about 150 ppm alkalinity for even the most acidic grists. So any guidance that tells you to add more than that to your brewing water, may be suspect.
The technique mentioned in Brewing Better Beer where roasted grain is withheld until the late stage of the mash can be effective in reducing the need for alkalinity in the mash, but it can still leave the pH of the wort in the kettle a little lower than desirable. So its not always a panacea for proper alkalinity adjustment.
Lime is one of the most effective and sure methods of controlling mash pH. But as Kai points out, if you don't properly calculate the lime addition and know the requirements of the mash beforehand, you can easily overdo it. And the consequences of overdoing a lime addition are much more detrimental to beer quality than to not adjust at all. When in doubt, leave it out or at least err on the low side when adding lime. Lime is a very strong base and it absolutely requires careful measurement and dosing. Do not think that you can just add a little and check pH. I find that this is a sure way to fail. I don't know of another program that provides a calculation for lime addition, so to brewers that don't use Bru'n Water, you may be out of luck.
For a large segment of water customers across the US, they don't typically have to worry about adding alkalinity in the first place. Their tap water has plenty of alkalinity and acidification or dilution is probably their primary concern. If you have water like that, consider blending a portion of your tap water with RO or distilled water when making a beer that needs more alkalinity to avoid an excessive pH drop. That might be a better alternative to adding lime. A lot of programs provide calculations for when RO or distilled water is used to dilute the tap water. That should provide an option to having to learn a mind-blowingly complicated program!