Mixing alk recipes?

[Mariner]

Randy,
I'm sure there's some reason I shouldn't do this, or you probably would have made it a third option in your DIY two part alk recipe -- but I'm interested in an alkalinity supplement with a more neutral effect on pH. My tank pH is usually right at 8.3 and I'd rather not move it up or down appreciably. Sooooo....what about mixing some baked baking soda with some unbaked baking soda? I think I've seen where people have mixed dry amounts of this at a 1:6 ratio and then made solution from that.
Comments? If this is not a good idea, which of your two recipes would you recommend for me?
thanks,
Mariner

 

[Randy Holmes-Farley]

My tank pH is usually right at 8.3

With what added now?

It is an OK idea, but more desired in theory by people who haven't used either than in actual practice. Few people find the fully baked version raises pH too much. That said, there is nothing wrong with using any ratio that you want, and something that is mostly unbaked and partly baked will have a pH effect that is quite small. You just have to work out the ratio to balance against the calcium part, and make sure that you do not try to make the alkalinity part more concentrated than will dissolve (use Recipe 2 amounts, for example).

Alternatively, you can just bake the unbaked version a tiny bit.

 

[Mariner]

Thanks Randy.
I've used several commercial buffers over the last couple of years. Mainly Kent's Superbuffer dKH at first, and more recently Seachem's Marine Buffer. I'm looking to keep supplement costs down as demand increases in my tanks (corals are growing!)
I try to dose a little every day (1/2 tsp per tank dissolved in a cup of RO water), but ALK typically remains on the low side (7 dKH), especially in the 40g SPS tank. I've been experimenting with increasing the dosage lately.
If I want to go with your half baked idea should I bake for say 20 minutes to 1/2 an hour or ?????
Mariner

 

[Randy Holmes-Farley]

I'm not sure how much baking would really result in partial baking. One easy way would be to use the unbaked recipe, but take out 20% of the baking soda, and give it the full bake.