62 watts for 2 36" bulbs is normal output. Do not go by wpg, it isn't very accurate. Do not do the MH, excel will not be able to help you enough. You will need co2. NO T5 fixtures cannot fire a high output (HO) t5 bulb. The opposite will work, but you cannot use HO in your NO fixture. Stick to low light plants, and just run the NO T5 bulbs (both 6000K-10000K). A low growing low light plant is Marisilea minuta, it will not grow fast under that lighting, but it will eventually carpet. More light doesn't equal more growth, directly. More light that is kept in balance with all the other parts of photosynthesis equals more growth. More light, that is out of balance with the other parts of photosynthesis, will only result in the quicker usage of nutrients until one is void. When that nutrient is void, the plants will not photosynthesize properly, resulting in algae.