Hi,
id agree with Michael W and id be more inclined to ensure good c02 to the plant than lots of light initially. Id start with your t8 lighting with reflectors. You cant overdo c02 (unless there is livestock already present in the tank), but its easy to add too much light.
You always can start with your current 80W T8 lighting system and then add more fluorescents if you notice that light if not enough.
Id agree with jose j here too, you can always increase light once you have a good balance and healthy plants, but if you use too much initially and your plants melt then it is costly to replace them. Once your plants have acclimated to submerged life and are healthy then you can add extra lighting for faster growth if you choose, but you will also need to increase c02 and ferts accordingly.
What results should i expect from things like HC with that sort of light? if i had two t8 tubes with reflectors.
Does tank height play a factor? as it is going to be quite a shallow tank- 37.5cm.
i doubt you will have very fast growth, but getting your plants healthy and sustainable from the start is more confidence inspiring than the alternative which is melt and algae. Of course if your distribution is good and c02 levels are very high then you can use more light, but give the plants time to adapt first.
Shallower tanks can be more susceptible to higher substrate par levels, but again this depends upon the lighting used, height of the lighting unit above the water surface, the hardscape layout and planting style, all of which can effect how light is filtered within your tank. Whatever the tank dimensions, its always a balancing act between light, co2, flow and fertilisers to get things just right.
Cheerio,
Ady.
cheers!
