FOWLR to REEF

[90G Mark]

As i have stated in a few posts I am slowly introducing coral to my 4 yr old FOWLR tank. from all the literature I have read the perimeters are so different. like salinity i use to run for my tank was around .023. so i slowly brought it up to around .026.. but i am curious about some of the others mainly for like SPS coral. will the high Cal. Kh and Mg be a strain on my fish.. my water change was about all i needed for my FOWLR tank. now I am learning all kind of chemestry..
My Questions Are:
Will the sudden change in Cal, Alk, and MG be a strain on my fish?
Should i pick a type of coral (Soft,LPS,SPS) to stick with so i can handle the perimeters. or is there a sweet spot that will accommodate for all types of coral?
also kinda off topic question, can that area at the bottom of a skimmer be used for like small ceramic media. to gain a little more surface area?

 

[Fudsey]

Cal, Alk, and MG shouldn't affect your fish if they are already acclimated to the salinity. Shouldn't be that much of a change you'll just be using them more with corals. Light determines what coral you want. You need high par/pur and high flow for sps, mostly. LPS need less intensity and can deal with at lot less flow. Mixed reefs are usually a little harder. Up to you which way you want to go, just do some research.