I have a 39 gallon with24" 17watts T8 light....6500k, 85 CRI...Trying to grow Amazon swords, Java fern, Anubis's... keeping light on 9 hours a day with liquid ferts...twice a week...There doing OK staying green all but the Amazon Sword...turning yellow and pale...Almost a year now since I started. Don't really want to get better lightning unless I have to
Really low light for plants
- Thread starter Thefisherman
- Start date
Not sure of the footprint and height of this size tank, but that is an extremely low amount of light in terms of the PAR/PUR it can put out. I don't care for the old watt per gallon for fluorescents rule, but it is kind of accurate for T12, T8 and T5 fluorescent. Minimum recommendation is typically 2 watts per gallon for low to medium light plants. On top of all that, you need to replace your fluorescent tubes every 6-12mo because their PAR/PUR output fades drastically, as does their color/temp and CRI. It may look fine to the human eye and still light up fine, but that means little.