According to this site the Coralife ColorMax
is actually 6700K, which should be perfectly fine for your plants even though the color's a bit odd.
Aggitating the water's surface will help to return the CO2
to ambient levels. In a tank where CO2
is being injected that means that surface agitation gasses off the extra CO2
reducing the CO2
levels. In a tank like yours, where CO2
isn't being injected the surface agitation helps to increase CO2
levels back to ambient levels making up for the CO2
used by the plants. This is why in your situation it is good to increase aggitation. If at sometime in the future you decide to inject CO2
, then you would want to reduce the surface agitation again.
There are lots of options for your substrate, of which Flourite is a good but exceedingly dusty option. I'd recommend checking out the substrate link in the Read This First Sticky for more information on your various options.