Why does everyone say these have to be replaced? are they uselless in planted tanks or do they just look bad?? they do have the same wattage as the regular bulb so I was wondering why do they need to be changed out to regular daylights?
Actinic bulb in freshwater planted?
- Thread starter aquaholic
- Start date
Plants need light between 6,500-10,000K wavelength (most bulbs labeled "daylight" are in this range), that's what they process for photosynthesis. Actinic is like 460-490K, way too blue for the plants to use, so your plants won't grow. They also give a very blue hue to everything in your tank. Some people like a bluer look and will use both daylight and actinic, if their fixture holds multiple bulbs. Others think the daylight look is best...but that's asthetics. When it comes to what your plants can efficiently use for growth, you want to stick with the 6,500-10,000K spectrum.
I have Actinic light on for viewing in the evening time after the normal daylight is off. Mine is a Toshiba Aquarium T8 Bulb claimed to enhancing the look of aquarium plants - are there any other problems having Actinic light on such as algae promotion etc. I would like to learn from this thread too.
Plants use light within the 400-700nm spectral range, so they can utilize the light from actinic bulbs. The problem with actinic bulbs is that they provide only light within the 460-490 range and plants need more than that, so using actinics exclusively is probably bad.
I'll get around to testing actinic bulbs with a PAR meter in the near future to see their real impact.
6,500-10,000k is the K rating, an approximation of the color of the light and has nothing to do with what plants need.
nguyendetecting
"Swim along with the snorks"
Actinics are mainly used on saltwater setups. You can use them on freshwater but they offer no real "benefit". Use regular daylight bulbs instead.
However, if your tank has night time occupants, an actinic bulb will good to use. I use one on my larger tank strictly for night viewing.
Use during the day is really a waste IMO.
However, if your tank has night time occupants, an actinic bulb will good to use. I use one on my larger tank strictly for night viewing.
Use during the day is really a waste IMO.
Seems like I just read the PAR vs. K rating discussion not too long ago with the impression that while PAR rating is the accurate way to go, your average fishkeeper is not going to own a PAR meter (as well as most bulb packaging does not contain this info) and that the Kelvin rating is a close enough approximation that plants do very well within that color range. Given the pride that goes with a beautiful, well planted tank, if another type/color range of bulb was more effective, I'm sure people would switch if the info was out there, but for the moment, the K rating is the industry standard. I would definitely be interested in seeing the results of the PAR test on actinic lighting, always good to increase the knowledge base. I'm also speaking from personal experience, I had a 10k/460 CF light in my fixture for close to a month (it's what came with the fixture, couldn't afford the new bulb) and I saw very minimal growth. After switching to a 6.7/10k bulb, my plants took off like nobody's business.
the question is will it do any harm? If wpg are reached with the regular daylight bulbs, and having more light will only increase chance of alea. will it hurt to keep the actinic bulb on with the other bulbs during the day if you like the color?