Most here know I do not use additives unless absolutely essential, so I tend to look at ingredients more and decide accordingly. My first issue is the sodium chloride (common salt) in Replenish; this has no value to plants, nor fish unless they are brackish (this gets answered by the source habitat which another member has detailed). So I can understand Seachem's saying that Replenish is not plant-oriented.
Equilibrium has more plant-needed ingredients, in my view anyway. [It used to have zinc I thought, but that does not matter.] Obviously Equilibrium is thus better for plants.
Another thing that strikes me, and @StevenF may be able to offer more on this, is that Equilibrium is derived from sulfates, whereas Replenish is derived from Chlorides. I may be mixing things up, but I believe Steven has discussed this in other threads, that sulfates are more readily taken up, or something? If this is somewhat true, it again points out the plant benefit of Equilibrium, which is what Seachem says.
To the issue of GH/pH for the axolotl. I would not change the GH with anything; the axolotl seems OK, and the plants certainly are with a GH of 4 dH. As for pH, plants don't care. Axolotl probably doesn't care either, if your pH is 7.5 as you mention above. So in my view, I would add nothing.
Equilibrium has more plant-needed ingredients, in my view anyway. [It used to have zinc I thought, but that does not matter.] Obviously Equilibrium is thus better for plants.
Another thing that strikes me, and @StevenF may be able to offer more on this, is that Equilibrium is derived from sulfates, whereas Replenish is derived from Chlorides. I may be mixing things up, but I believe Steven has discussed this in other threads, that sulfates are more readily taken up, or something? If this is somewhat true, it again points out the plant benefit of Equilibrium, which is what Seachem says.
To the issue of GH/pH for the axolotl. I would not change the GH with anything; the axolotl seems OK, and the plants certainly are with a GH of 4 dH. As for pH, plants don't care. Axolotl probably doesn't care either, if your pH is 7.5 as you mention above. So in my view, I would add nothing.
I would go with a calcareous substrate. The only issue here is that the minerals will dissolve, raising the GH/KH/pH, but you don't know how high these may go. At least, I have no idea. When I had my tank of mollies, and rift lake cichlids, in the 1980's I used a substrate of dolomite. Never measured GH/KH back then, but the pH was good for these fish and that was all I cared about.
