Re: Water chemistry assistance


Get rid of your ion exchange resin, you dont need it.
10 mg/L of alkalinity is not a lot. You could add much more baking soda 
than you are adding at present ... of course your fish may suffer if you 
add it too fast.
What is the hardness of your tap water? ... if it is 7 then something is 
removing the cations from solution in your tank.
IMHO, the loss of Ca and Mg has nothing to do with more light or CO2 ... 
you dont have enough plant material and the pH isnt high enough for you to
be losing cations through Ps mediated precipitation.