A coloured glass absorb more light. All the coloured bulbs ive seen are far less efficients than normal one. If you want a very especific spectrum, try the special color wich some brands have (reds from Osram and Phillips, as well as blue; in CFL, Osram have the DuluxS 9W in both and Dulux L 24W in blue).

When using CFLs, as large the watage per tube wich form the bulb, best efficiency. CFLs below 26w have very poor efficiency (less than 65lm/w in 830 color). Higher ones give from 65 to 75 lm/w. And the more efficient CFLs are of type L (they are like a fluo tube bended by half, forming a twin tube), wich reach 87lm/w. They have other advantage, they are no integrated CFLs, so you can put the ballast outside the cabinet, reducing heat, and they achive a more even lighting, better when grow SCROG and SOG. And when you replace it, only must buy the lamp, not the lamp and ballast.

I grow in 5 sqft with 4 DuluxL 55w /830 with very good results.

All brands type L CFLs are compatible between (Osram Dulux L, Phillips PL-L, Sylvania Linx L, GE Biax L ...) and higher watages (>36w) need electronic ballast (they are relative cheap, a good investment, paid itselves in 1-1,5years).
knna Reviewed by knna on . Compact Fluorescent Light Discussion So here we go again pot fans. BlackJack Round 2. germinating 6 seeds directly in soil. For those that followed my last grow, enjoy. For those that are following it for the first time...Enjoy :) I'll keep ya updated as the weeks go by. Rating: 5