I have some puffers, they have been living in 7 at the store, so I put them into 7 when I brought them home. Eventually Im thinking I will switch to victoria malawi buffer when making water for them since it will buffer near 8, but as of now I must slowly raise the pH, thus the crushed coral which is supposed to help to keep the pH at 8 in the future (also it looks so much better than gravel)
So I am going to transfer them into their new tank which has coral substrate.
I'm not sure what happens when you have two buffers at different pHs competing against eachother. I know the water's current buffer is more stable than the carbonate based coral, also the coral will be as a substrate and not dissolved in the water, so I dont know which will prevail.
Ultimately, I know that fluctuating pH is more dangerous to fish then slightly low/high pH, so I would rather stick with a phosphate buffer, but as you know phosphate buffers cannot reach a pH of 8. I would consider using alkaline regulator which should hold at a max of 7.6, but again I want to know what will happen when a 7.6 phosphate competes with an 8.0 carbonate buffer.
Also I want to know what happens in terms of the chemistry when two buffers compete. The only thing I can find online about it is this and it would require that I know the pKa and molarity of both buffers, which I dont have due to a) seachem's proprietary forumulas, and b) how to quantify those figures given a bed of irregular-shaped coral fragments instead of an aqueous solution.
So any explanation, either practical or technical, would be welcome.