Spiral Compact Flourescents in Planted Tanks?

[redfraggle]

I'm planning to start a low-tech 10g planted. I was considering buying a 10 gallon starter kit from my LPS and replacing the 2 included incandescent bulbs with 2 15W daylight compact fluorescent spiral bulbs.

My main question is: Are these shape bulbs suitable for dispersing light well in an aquarium (specifically 10 gallon)?

I am also wondering what level light this would be considered - I know that smaller tanks don't necessarily follow the 2W/gallon rule, but I don't understand the mechanics there. They make higher and lower wattages of these bulbs, so there is a bit of flexibility here (provided the bulb itself will work).

Any thoughts or experiences would be greatly appreciated.

 

[mfdrookie516]

Two of those 60w equivalent bulbs will work fine. Walmart actually carries a bulb that is a bit better suited in their pet department. Rather than being twisted, they are just 'U' shaped. That's going to be lowish light. You can probably do some medium stuff, but nothing really light demanding. The cool thing about plants is that they are cheap, so if you want to try something, you're not out a lot if it doesn't work.

 

[redfraggle]

Thanks! I looked up the bulbs you mentioned and I see that Coralife makes a 20W version of the u-shaped bulb for freshwater - so the lighting would be upgradeable if I decide I need it later down the line.

 

[jetajockey]

The WPG rule doesn't work with smaller tanks just like it doesn't really work in general. The reason is because it really has to do with PAR, and that's determined/guesstimated by bulb type, distance, reflectors, etc.

The spiral bulbs have a lot of restrike because of their design, but they work well. I honestly think that because of their design and the general design (or lack thereof) of standard screw in hoods, there is a lot of room for light efficiency improvement. The U shaped lights are great, and putting in DIY reflector is even better, although it honestly may end up giving one too much light.

 

[BigJim]

CFLs aren't ideal, but they're cheap and effective if your expectations are reasonable. I've got a pair of 18W daylight spectrum CFLs over both my 20L and my 29g. They definitely work better over the shallower 20L, but I've got a forest of crypts, java ferns, and anubias growing in my 29g. Water sprite grows like a weed in my 20L, but it doesn't do so well in my 29g.