What are the light values of energy saving bulbs?

Is anybody aware if the compact energy saving light bulbs are sufficient for plant growth. After seeing some of the living masters pieces that have been created by a particular member on this forum I am going to have a crack at it myself (with the minimal cost possible). I am going to be using a DIY suspended overtank luminar and I'm trying to suss out what are the cheapest fitting and bulbs to purchase that are sufficient for plant growth?

Any ideas would also be appreciated?

Thanks John for the information. To follow up on the topic in question. I took myself out to the local hardware store today to riffle through their selections of fittings and bulbs to see what would be suitable for a planted tank.

Unfortunately and as I had expected very few manufactures give the actual kelvin rating of the bulbs they produce. Only one manufacture gave the kelvin rating for their compact fluorescent energy saving bulbs. John, there is a reason why they killed your plants and that is because the Kelvin rating in 2300.

I did however find a little pearler of a lighting unit stuffed away in the back of the lighting display. It was an energy saving T4 fluorescent tube unit with a quality \"6400 kelvin\" rating They came in a range of 10, 16 and 20w and at a cost of €24 for the largest 20w unit (ballast and bulb). The units and bulbs are very thin but would cover the length of most any medium sized tank. Also the replacement bulbs for the 20w units are €7, a far cry from the more expensive T5 and T8 tubes. Of note, on the packet it also mentioned that the 20w T4 bulb gives off the same amount of light as a 100w T8 bulb! Does this make sense! Would this mean with two 20W T4 units I would have the same amount of light as Two 100w T8 tubes???

I didnt buy them yet as I thought I would check them out with you guys on here first! But, I do think they could work!

Has anyone one else tried these fittings and T4 bulbs before? or if you haven't maybe you have discovered a reason why you can use them!

I too have checked for replacement tubes for my 25w T8 and 24w T5 compacts. As you found out Denis, it's very hard to get bulbs in the right Kelvin range. Most are around 3 or 4k.

If you do find a bulb, you need to ensure that the fitting is at least splash proof. Needless to say, water and electricity are not a good mix.

They units are designed for kitchens and bathrooms so they would definitely be splash/moisture proof. I wouldn't classify them as water proof/resistant but they would be going in a DIY suspended overtank lighting unit, which will most likely have a protective perspex shield. I haven't thought much about its design yet but as you mentioned I will definitely be taking the water/electricity thing into consideration!