I secound Smidy. Dont mess about trying to recreate wild conditions. Just ends up stressing you out and more importantly the fish. I have never checked my water conditions. Even now I dont know what the exact PH is.
But I do know that with my gravel and limestone rocks that the PH is well over 7.
My Tangs, Tropheus & Alto's, wont stop breeding so all must be good.
Just dont do more then 20% water changes for the Tangs. Malawis will handle more.