Hi. If the glosso is growing up instead of creeping, the primary problem is that the lights are not bright enough. 2 x 6W for a 30" tank (assuming it's on "low" stands and only 3" or so above the water). I would suggest doubling it (24W) at least. Some may even go higher at 36W; but I think that's probably overkill. 12 000K is rather "blue", but probably fine; though I have not experimented with that high Kelvins; "typical" for planted tanks are 6500k - 10000k.
The 'side effect' of high lights is algae growth, so it's always a juggle between good (creeping) growth and algae control. The CO2 dosing would help somewhat in keeping the plants happy to take all the light and nutrients before the algae takes over. All the best!
Bookmarks