Good start, but you'll still need to have fertilizer if you want growth. Contrary to popular belief, you probably don't have excess nutrients. excel is NOT causing your algae. when your plants aren't terribly healthy, and you're putting a lot of light into the system, you're going to get algae, pretty much guaranteed, regardless of nutrients.
Many people here will tell you that the WPG rule is VERY outdated. you have T5HO, which are WAY more efficient than the relics of the days when WPG was still relevant. You can measure light in these newer devices more accurately with something called PAR. Thankfully, there are some awesome members here, so you won't have to go out and buy a PAR meter. There's some extremely valuable info here
. I recommend you read that entire thing.
useful. A quick look at that tells me you have an obscene
amount of light, even with just one bulb. But I still recommend you read it, i haven't had to worry about this in a while, so i might be off.
With high light and co2, you are going to need fertilizers beyond what your fish excrete, especially if you're looking for anything lush. if it continues like this without ferts, in 2-3 months, you'll probably have dead plants, algae, and frustration. (trust me, been there, done that
)check out the links i posted above. like i said, excel isn't a 'nutrient'- it's just a chemical that breaks things down to make carbon, aka co2 substitute. After co2, which you already have, plants need macros (nitrogen, potassium, phosphorus) and micros.
the drop checker is not critical but is important. you don't want to gas your fish. you should know how much co2 is dissolved in your water on a continual basis, the drop checker will tell you this, bubble rate will not. Bubble counter just tells you how much is coming out the the reg. It's a slight, albeit very vital, difference.
You have a very nice system here. it'd be a shame to let it go downhill. If it's the price that's turning you off, these things can be pretty cheap. there's a user here whose screen name is nilocg. send him a pm and he can ship you ferts and a drop checker for pretty cheap.