Sorry for the confusion. so the article that I was hoping you would read was Understanding Calcium and Alkalinity. on page 1 of the helpful articles. Is that the article you read? Did you read the whole article?, Do not confuse alkaline as it refers to Ph below 7 and alkalinity as it pertains to DKh hardness.
If you read the whole article and dont get it, what do you not get. the article gives you several ways to balance out your calcium, alkalinity, and ph. let me know what is confusing and Ill try and help some more. I am just a little mystified as to why you are out of sinc with water parameters, your system must not be completed sufficiently, and your salt water mix for water changes must be lacking something, also high co2 is an indication of not enough gas exchange at the surface and must be corrected. so. one thing at a time, add a skimmer next once running properly for a couple days check the co2 and water parameters again and see where we are at. If the tank water starts to smell rotten and not like fresh saltwater/ the ocean, do a water change 25% plus. (I fear I have given you too much to digest too quickly and will try to help when I know what the confusion is). let me know. you may pm me also.