I don't have any experience with hairgrass, but some points here should help you.
1. You have a lot of light there. First and foremost, make sure that your CO2 remains high and stable. You mention your pH is 7.5, you should take a sample of water from your tank and let it sit out at room conditions for 24 hours, then measure your pH again. In order to have around 30ppm of CO2, your pH needs to increase by a full unit to 8.5. If it does, I assume you also have quite hard water. In any case, a change of pH of 1 unit is the ballpark you want to go to. The bubble count is meaningless in knowing how much CO2 you actually have dissolved in the tank's water.
2. You need to maintain in your tank nitrate (NO3) levels around 15ppm, and phosphate (PO4) levels around 2ppm. From your readings of no nitrate, it appears that the 'Daily Grow' you are adding is not meeting your needs. You need to look at the label and see what the make up of that product is so you can determine how much you are actually adding. Check out this link: http://www.aquatic-plants.org/articl...ges/index.html
for some good basic info regarding planted tanks. You can get dry ferts from Greg Watson for your macros (NO3, PO4, potassium). Then you can add a separate solution on different days to supplies your micro elements and iron.
Again going back to your lighting, keep in mind that with high light, the demands on the tank for fertilization is greater than with low light, and if you don't keep up with those demands, algae will follow. Good luck.