I don’t add KH to shrimp substrate only GH. I use ‘salty shrimp’ had a lot of success with that method. Yes you will likely wear out the substrate if you add KH and I don’t think it’s necessary at all. Highly recommend giving that method a go, those substrates should be able to do the job great without any KH added IMO.
First two doses of Kh on this past Saturday. Hesitant to dose again because ph has been steady 6.6 for two days. Relatively new tank (two weeks since live cycle) should I expect Ph to keep leaching or will it balance out with water changes? Should I consider using rocks that raise ph or does this and dosing ruin the substrate? Pretty sure Kh and Gh are around 4 currently.
Bigcaptain_4709 
I don’t add KH to shrimp substrate only GH. I use ‘salty shrimp’ had a lot of success with that method. Yes you will likely wear out the substrate if you add KH and I don’t think it’s necessary at all. Highly recommend giving that method a go, those substrates should be able to do the job great without any KH added IMO.
First two doses of Kh on this past Saturday. Hesitant to dose again because ph has been steady 6.6 for two days. Relatively new tank (two weeks since live cycle) should I expect Ph to keep leaching or will it balance out with water changes? Should I consider using rocks that raise ph or does this and dosing ruin the substrate? Pretty sure Kh and Gh are around 4 currently.