but the K2S04 is optional since you are dosing K with the N and the P
Some say it is optional, but I would not completely over look it, the 'S' is also a much needed nutrient that is rarely recognized, and needed by the plants in at least mIcro form, if one is only using CSM+B as a trace element, then adding K2S04 is an additional plus. CSM+B has zero 'S', where as Flourish and Tropica does contain some.
I personally have seen positive results from dosing K2S04 at least once a week.
Each individual must work out their own salvation for the tank they maintain.
It is cheap, easy to dose and certainly does not hurt.
Somewhere along the way in your planted tank en devours I would also purchase Flourish Comprehensive and some Tropica plant nutrition to dose as trace minerals on occasion.
I use CSM+B most of the time, but I do also use the other trace elements available at various times, usually once a week, one or the other, then use CSM+B for the rest of the week.
With only 2WPG you would not need to dose all that 3x a week, that would be a bit to much, unless you increase your light.
This is where the +/- comes in.
+/-1/4Tsp KN03 3x a week
+/-1/16Tsp KH2P04 3x a week
+/-1/16Tsp K2S04 3x a week
+/-7ml Trace 3x a week
+/-1-2ml Fe/Iron 3x a week- again, with only 2WPG you can get by without this, there is enough in the trace mineral, unless you pump up the light.
+/-1/2Tsp KN03 2x a week
+/-1/8Tsp KH2P04 2x a week
+/-1/8Tsp K2S04 2x a week
+/-10ml Trace 2x a week
+/-2-4ml Fe/Iron 2x a week