[cS]

I doubt that your macros are deficient. If I remember correctly, the maximum uptake of N per day is 3-5 ppm. Your fish load and KNO3 input should be ample.

What is your tap water GH, along with individual Ca and Mg concentrations if available? What is your CaCl2 dosing regiment (quantity and frequency)?

Also, why is your CO2 fluctuating so much between 10-25 ppm? Do you have it off at night? Nonetheless, like Ben suggested, I would amp it up more consistently around 30 ppm.

 

[cS]

Tap GH is 10.

:shock: Hehehe. And here I was thinking that you're somewhere nearer to 1 dGH.

CaCl dosing is 1 tsp daily. In my tank that translates into about 1 ppm daily, at least according to fertilator. Also, when I add this, it clouds the water substantially and for almost the entire day. This leads me to believe that there's plenty of Ca in the water (don't know if that's true) and that the problem lies elsewhere.

The addition of only 1 ppm Ca per day SHOULD NOT make the tank cloudy for almost an entire day! If your CO2 is adequate then the CaCO3 should dissolve within a couple of hours (less in your case of only 1 ppm Ca). Do let us know how your tank fare with the new 24/7 CO2 schedule.

P.S. I definitely agree with Naomi - go big. :mrgreen: