I've been lurking on the site for sometime and have read hundreds of pages, especially in the low tech area.
Been running my tank for 15 years, switched to plants 3 months ago, working out lighting issues, Ordered to 3 X 54 catalina fixture for my 90 gallon 24 inch high South American Tank. Using only one light for 6 hours and a 2 hour mid day burst at noon with 2 bulbs. Never with all three. NO CO2 light ferts. Light 2 inches above tank, with very cloudy glass top.
Thinking that running NO lights in 2 bulb circuit. With the great reflectors from Catalina, I believe that will give me good low light.
My hats off to HOPPY for all the great info and reads, you've kept me busy for many weeks..