Laconic

I use 3 x T8 38w (2 x Arcadia Freshwater Lamps and 1 x Original Tropical) for my 48x18x20 Tank (~75 gallons). That amounts to about 1.6 wpg, which by most conventional measures is quite low. I use pressurized Co2.

I have no problems growing fairly light demanding species such as Eriocaulon Cinereum and C. Parva. While I do not get pearling, or intense red colouration, I believe it is indicative that the WPG rule ought to be taken with some caveats. As a quick and dirty measure, it is adequate but definitely it is not the be all and end all with regards to lighting.

brownietrout

i have a 55 gallon with diy co2 and 2 coralife-65w 8000k compact florescents.
My plants are growing well but I don't get pearling, which I would love to see, and the colors are not showing the red I would also like to see.
Any suggestions on how I could improve my light output without buying new fixtures at this time.

Newt

Get bulbs other than Coralife. They all have way too much green in the spectral output.

brownietrout

opps. I have 2 coralife fixtures with 2-AGA-8000k full spectrum compact flourescents

mudboots

I looked into the thread on PAR vs WPG and my numbers just don't quite add up with regards to wpg recommendations. I put the numbers on that thread, but as far as this thread goes, I have a 20 npt with 2.5 wpg T5HO (2x24w) with no problems growing stems, and a 125 npt with only 1.25 wpg T5HO (4x39w) with no problems growing stems except in shaded areas (some Rotala bit the dust after a 1 week bout of pea soup). I have to mention though that these set ups are pretty new, so I don't have long-term observation to confirm how well everything is doing. They have been set up about a month or so.