ATI true actinic or blue plus?
- Thread starter Red254
- Start date
Dave Thebrewguy
New member
I'd always understood that Actinic lamps generally covered most of the spectrum from 410-420nm to 460-470nm with peaks around 420nm and 455nm). It is also my understanding that the Blue Plus also includes some of the spectrum above 470nm (daylight), similar to the "50-50" lamps thast were popular "in the old days," but with less than 50%of the "daylight" component.
Dave Thebrewguy
New member
Sorry to say it, but this is probably the least accurate thing I've ever read on RC.
The part of the spectrum produced by most actinic bulbs are the same wavelengths required by your livestock, that, and a narrow band of red that is only present in fairly shallow water. Keep in mind that the human eye is not very sensitive to light at the violet end of the spectrum, that does not mean that the bulb is dim, just that you can't see the light with your eyes.
PAR measures the quantity of light from 400nm to 700nm, but light in the 480nm to 625nm range is pretty much useless as far as chlorophyll is concerned and light above 625nm is not available to many marine organisms in their natural environment.
That "violet, dim" light puts out a lot more Par than you think. You could have a thriving reef with only actinic lamps, but you could not have a healthy ecosystem without the light they produce.
Edit;
BTW, for the OP, I took a peak at the information for the Blue Plus and True Actinic to refresh my memory. The True Actinic is exactly that, 400nm to 470nm with a (useless) narrow peak at 550nm. The Blue Plus produces light from around 400nm all the way up to 550nm (with that same useless peak). I did not take the time to compare the output levels at the various key wavelengths but it's safe to say that they both use the same amount of electricity and probably put out similar quantities of light, the difference is that one puts out light that we can't see very well, the other puts out some of that same spectrum, but also emits light that looks bright to us but is useless to our livestock.
Last edited:
the blu plus blows away the true actinic bulb in par. if u ran all true actinics the sps would not have enough par to thrive. if u ran all blue plus the sps would be fine because there is enough actinic part to the blu plus bulb. the only problem with all blu plus bulbs is that the tank would look to blue to the eye. rtparty was correct
solitude127
Proud user of IO Salt!
Blue + for me. I haven't used an actinic bulb in 3 years
edwin-orellana
New member
Blue+ is what I use also....tons of par=good for sps
Just to throw in my 2 cents, there is no question that the PAR is higher in the blue plus bulbs. However, a greater percentage of the light emitted is photosynthetically useful in the actinics.
That aside, what I noticed personally is that when I ran a combination of white bulbs (12K or 14K) with blue bulbs, the greens of my corals became washed out. When I lowered the light output by reducing the number of white bulbs and replacing some of the blue bulbs with actinics, the greens came back in full force. The downside is that the tank is not as visually bright as it once was.
So basically, I guess it all depends on what you want - do you want a visually bright tank, or one with more vivid coral colors...
That aside, what I noticed personally is that when I ran a combination of white bulbs (12K or 14K) with blue bulbs, the greens of my corals became washed out. When I lowered the light output by reducing the number of white bulbs and replacing some of the blue bulbs with actinics, the greens came back in full force. The downside is that the tank is not as visually bright as it once was.
So basically, I guess it all depends on what you want - do you want a visually bright tank, or one with more vivid coral colors...
Khemul
New member
People put too much value on PAR. It isn't everything. And the required values for reef tanks are often drastically overstated. It can be a good guideline but it isn't perfect by any stretch.
The key differences are as Dave Thebrewguy said. The Blue Plus is designed to give your tank a more visible blue color. The True Actinic is designed to supplement your lighting and bring out colors.
Both will grow and support a tank perfectly fine. It's just that one will have a higher benchmark score and look brighter to the eyes. That doesn't mean that one is that much better then the other. It just means that one scored a higher benchmark score and looks brighter to the eyes.
The key differences are as Dave Thebrewguy said. The Blue Plus is designed to give your tank a more visible blue color. The True Actinic is designed to supplement your lighting and bring out colors.
Both will grow and support a tank perfectly fine. It's just that one will have a higher benchmark score and look brighter to the eyes. That doesn't mean that one is that much better then the other. It just means that one scored a higher benchmark score and looks brighter to the eyes.
Dexters Reef
New member
See my sig for t5's 
. I'm happy
. I'm happy
dan-in-gr
New member
Hi, I have a dual 250 MH with 4 T5's, when the bulbs were one year old in March, I replaced the 4 original Giesemann True Actinic with 4 ATI Blue Plus, while very good looking it took me several months to realize my SPS lacked something, two of the T5's are being replaced next week with ATI Actinic, so I will have two of each type.
If you have a fish or softies, maybe some LPS, then Blue Plus would be fine, but SPS really pops with the Real 420nm Actinics.
If you have a fish or softies, maybe some LPS, then Blue Plus would be fine, but SPS really pops with the Real 420nm Actinics.
usefulidiot213
Bryan H.
I have always used both. Two Blue plus & two Actinic. Been happy with it.
Similar threads
- Sticky
