LED thinking
Have been wondering whether the Grobeam 500 12W does produce enough light for my 70L tank, as my plants just aren't pearling. After quite a lot of research, uncovered this very detailed American review of LEDs compared to other lighting options.
Scroll about half way down for the detailed LED section. The upshot is that "a high PAR/PUR LED from the most exclusive/best emitter bins can only need 4% of the wattage as a household T12 to produce the same results [or] ... about 17% for better aquarium T8 or T12 lamps" and that "It is still easy to make assumptions from the raw data based on this study with plants that a 12 Watt LED can at least replace a 100 watt MH of equal Kelvin ratings"
Here's the test result comparing Metal Halide and LEDs:
The helpful American chap says that when "the outdated 'watts per gallon rule' for planted/reef aquariums (@ 4 watts per gallon) is applied to a TMC GroBeam (as an example)" that for "a high light planted freshwater aquarium .6 to maybe .8 watts per gallon are required."
Translating this into British English :silent:, means that 0.16 - 0.21 LED W are needed per litre. So my 72L tank (for example) requires 11.5W to 15.2W. So I'm pretty much ok with just the one 12W Grobeam, but could push it to 2 for a serious light overload...
So I think the explanation for the non-pearling has to be CO2 related - given that the HC pearled as soon as it went in but hasn't since - and I've definitely got enough ferts in there!
Have been wondering whether the Grobeam 500 12W does produce enough light for my 70L tank, as my plants just aren't pearling. After quite a lot of research, uncovered this very detailed American review of LEDs compared to other lighting options.
Scroll about half way down for the detailed LED section. The upshot is that "a high PAR/PUR LED from the most exclusive/best emitter bins can only need 4% of the wattage as a household T12 to produce the same results [or] ... about 17% for better aquarium T8 or T12 lamps" and that "It is still easy to make assumptions from the raw data based on this study with plants that a 12 Watt LED can at least replace a 100 watt MH of equal Kelvin ratings"
Here's the test result comparing Metal Halide and LEDs:
The helpful American chap says that when "the outdated 'watts per gallon rule' for planted/reef aquariums (@ 4 watts per gallon) is applied to a TMC GroBeam (as an example)" that for "a high light planted freshwater aquarium .6 to maybe .8 watts per gallon are required."
Translating this into British English :silent:, means that 0.16 - 0.21 LED W are needed per litre. So my 72L tank (for example) requires 11.5W to 15.2W. So I'm pretty much ok with just the one 12W Grobeam, but could push it to 2 for a serious light overload...
So I think the explanation for the non-pearling has to be CO2 related - given that the HC pearled as soon as it went in but hasn't since - and I've definitely got enough ferts in there!