Maintaining alkalinity levels

[Delphinus]

The calcium reads 400 which by itself sounds "not bad" but because of the lower Alk, "nobody's using it." So raising your effluent rate from the reactor may initially bump the Ca up as well, but as the Alk raises the consumption rate for the Ca will also rise, thus the Ca will come down and stabilize.

What your readings tell me is that your effluent rate can be increased (the CO2 will need to be adjusted appropriately). I aim for a pH of 6.7 in the reactor, that translates roughly into equivalent of "effluent has an alk 3x of your desired tank levels".

That said, since your Ca&Alk parameters are slightly off balance, you may be better off in the short term to use a 2-part to acheive that balance (in addition to increasing your reactor's output). Reason being that the reactor should be used to maintain the levels rather than "raising them from point X to point Y."