I Suggest Adding A UV Sterilizer to Your Aquarium And Moving Your Light Closer
The hairgrass is alive, but quite thin compared to when the light was closer (When I set up the tank).
I do not want to have an algae outbreak again so I'm toying with dropping the light an inch to increase the PAR value at the substrate surface, alternatively, I can increase the photo period or the amount of light
I've read that dwarf hairgrass likes 2WPG or more. That being said, I know to focus on PAR vs WPG as a measure of effective light.
In my experience, Dwarf Hairgrass can survive in a lower light condition, however, does much better with higher lighting, CO2, fertilizer tabs and liquid fertilizer dosing at least once a week.
I have noticed that a number of people follow the EI dosing index which seems to work well for them. However, this can become very expensive over time.
I maintain a few planted aquariums with both dh and microsword and have found that it is nearly impossible to create the perfect chemical balance to achieve equilibrium in an aquarium. There are simply too many variables which affect the water column.
I have, however, found that using uv sterilization in my aquariums has not only ridded my tanks of green or cloudy water, but also allowed my plants to propagate more successfully, simply because there are less organisms in the water column which were feeding on the nutrients that my plants also required. This means that my plants no longer have to compete with these organisms as they did prior to the addition of the uv sterilizers.
Not only are my plants healthier than before, my fish are also much more active, and their colors are more vivid due to the better water quality.
I have been using uv sterilizers for the past year and half and cannot over emphasize their importance in helping to maintain a healthy water column.
As for lighting, I use Hagen GLO light fixtures with 6700 Kelvin bulbs in some tanks and a combination of 6700K and 18000K in others, and they work quite well.
I am presently setting up a 5.5 gallon nano aquarium to house some shrimp in, and looking for a good nano light. The Fluval CP mini is about 12 or 13 watts, which might work well, since I want to keep dh and microsword in this tank as well.
However, I am also considering the AquaTop Nano Type P for this aquarium. Yet, at only 7.5 watts, or about 1.3 watts per gallon in my 5.5 aquarium, I am not sure if this light will be powerful enough to grow these plants successfully, even if its 6500K spectrum is ideal for them.
I have been unable to find any independent reviews on the AquaTop Nano P light, so I may just have to purchase one to determine how well it works.
It's a very high tech and sleekly designed lighting system which usually sells for about $70 - two and a half times what the Fluval mini sells for.
And if I were to purchase two mini's that would equate to about 26 watts of light - roughly three times the power of the AquaTop.
Given this, at least on the surface, the AquaTop seems overpriced. However, when you consider the cost of some of the ADA lighting fixtures (and their low watts per gallon) the AquaTop may turn out to be good value if the light is capable of supporting plants like dh and microsword.
As for the importance of PAR over watts per gallon, Takashi Amano's planted tanks grow quite well under very low lighting conditions, so perhaps the AquaTop Type P will work fine.
I may try it and will update this post based on my experiences with the AquaTop light.