in a month or two i need to repalce my pc bulbs and i was thinking of just getting 6,700k bulbs (x4) with out actinics. are actinic bulbs as important as daylight bulbs or can i get by without the actinics? i have a 50gallon lps tank and the dimensions are 36"Lx18"Hx15"W. thanks
How important are actinics?
- Thread starter Jiggz
- Start date
Horace
New member
Sorry guys, but actinics DO have a purpose. You can even grow corals under pure actinic if you want. You have to remember that most corals are found deep enough where the majority of thier light is actinic in spectrum. Very few corals get blasted with 10k light all day and thats it. In fact some of the best colored tanks are those that have low PAR and high amounts of blue spectrum light. PAR is not everything by any means. Spectrum plays a very big role.
I used to think the same thing as those above...after examining several high end tanks and talking to those people, my opinion has changed.
I used to think the same thing as those above...after examining several high end tanks and talking to those people, my opinion has changed.
Actinics will provide photo spikes that daylight cant. Actinics represent dusk and dawn.
Are the essential? I would say yes, as you want to imitate the natural lighting conditions one encounters on a reef.
A optimum photo period
Actinics on one hour before and off one hour after yourdaylights go off
Go with a 10K or 12K daylight to complement your (Royal blue)actinics. 6700K is very yellow and you will lose some of the colouring in your fish and corals.
Are the essential? I would say yes, as you want to imitate the natural lighting conditions one encounters on a reef.
A optimum photo period
Actinics on one hour before and off one hour after yourdaylights go off
Go with a 10K or 12K daylight to complement your (Royal blue)actinics. 6700K is very yellow and you will lose some of the colouring in your fish and corals.
smleee
New member
Yes, the spectrum is very important for corals, as is PAR, but when talking about "actinic" vs. "daylight" bulbs, the daylight bulbs provide a large amount of light in the 450nm range, they even have a large peak in that area, which is why it is still ok to use all daylight if you wish and also why "actinics" aren't as important as for coral growth when you have daylight bulbs; though we both agree that you do need the "actinic" (420-450nm) spectrum. Here's a graph of intensity of a 6,000k daylight T5 bulb (I couldn't find one for PC's in 10,000k or 6,000k).
eee
eee
smleee
New member
Sure. 
My advice would be to go ahead and get the 2 - 10k's and 2 - actinics. Then try putting in your old 10k's along with the new 10k's (with no actinic) and see if you like it (though I doubt you will). I would also like to suggest the Current brand of bulbs as they have a proven track record and are a quality product. On another note, the "dual" actinic bulbs they make (which is a bulb that is half 420nm actinic and half 460nm actinic) are great because they will provide you with spectrum peaks in both 420 and 460 nm ranges and you will get more fluoresence from them than an actinic bulb with just 420nm or 460nm alone.
eee
My advice would be to go ahead and get the 2 - 10k's and 2 - actinics. Then try putting in your old 10k's along with the new 10k's (with no actinic) and see if you like it (though I doubt you will). I would also like to suggest the Current brand of bulbs as they have a proven track record and are a quality product. On another note, the "dual" actinic bulbs they make (which is a bulb that is half 420nm actinic and half 460nm actinic) are great because they will provide you with spectrum peaks in both 420 and 460 nm ranges and you will get more fluoresence from them than an actinic bulb with just 420nm or 460nm alone.eee
smleee - I have the Current Outer Orbit which includes actinic 420/460 nm pc bulbs along with the 10K MH. Can you explain further what value the 420/460 has over just a 420 or a 460 alone. I love the Current fixture, but was thinking I would like a more blue hue to it when I replace the bulbs.
RichConley
New member
Horace, your average 10K 250 halide puts out more blue light than VHO actinics. Actinics are for looks
The thing is, a lot of corals DO look better under actinic. The color hasnt changed, its just being accented.
smleee
New member
besl:
IME and others too, using just a 420nm or 460nm alone will get you good fluoresence and provide for the proper spectrum that corals need but it is limited in what colors it will "bring out" of corals. Using a "dual" approach, you get peaks in spectrum at both 420nm and 460nm which will provide fluoresence in different corals and different colors. IMO growth wise and coral requirement wise, 420 or 460 alone is just fine; but to get the most colors out, go with the dual bulb. HTH.
Oh, the 420 is more purple and the 460 is more blue. But IMO (not tested with equipment, just my eyes), the purple has about 1/2 the brightness of the blue. I have switched between a full 420 bulb and a full 460 bulb and noticed this in dawn/dusk periods.
eee
IME and others too, using just a 420nm or 460nm alone will get you good fluoresence and provide for the proper spectrum that corals need but it is limited in what colors it will "bring out" of corals. Using a "dual" approach, you get peaks in spectrum at both 420nm and 460nm which will provide fluoresence in different corals and different colors. IMO growth wise and coral requirement wise, 420 or 460 alone is just fine; but to get the most colors out, go with the dual bulb. HTH.
Oh, the 420 is more purple and the 460 is more blue. But IMO (not tested with equipment, just my eyes), the purple has about 1/2 the brightness of the blue. I have switched between a full 420 bulb and a full 460 bulb and noticed this in dawn/dusk periods.
eee
smleee - excellent response... I now understand the purpose of the dual wavelength 420/460 nm and will stick with them. If I still want a slightly bluer hue to the water, should I change my 10K (150W) MH to 14K (150W) MH? I I mentioned earlier this is in a Current Outer Orbit, and their 150W MH choices are either 10K, 14K and 20K.
smleee
New member
While I have no hands on experience with MH, I do know that for a given brand of bulb going from a 10k to a 14k will make it more blue, but at the expense of output (PAR). So in a sense you will be giving your corals less usable light to grow. I believe one of the higher PAR rating 14k bulbs out there is a Phoenix bulb, but I'm not sure if that's SE or DE (I think your Orbit uses DE right?) I think you will have to research a little on PAR outputs on your MH bulbs and others, and make a decision from there.
eee
Horace
New member
While you may be right, a daylight bulb does put out a good spike in the blue spectrum as well....the point is that actinics do more than just make your corals look good. They actually do add to the very useful blue spectrum which DOES make the corals grow. The point I was making is that actinics are not worthless and do provide more than just simple flourescence. Would I want to grow my corals on actinic alone??? Definatly not, but they do add to your daylights in more ways that one. I think we all agree, that corals just simply look like arse if you dont have some strong blue spectrum in there, be it by having high kelvin bulbs or supplemental actinics.
DesertBandits
New member
How do people grow the most light needy corals? Iwasaki 6500k and XM10K. Blue bulbs just look good, they don't help with growth in anyway comparable to a balanced spectrum bulb, end of story. Jiggz if you wanted more light output for extra growth, get all 10k daylights. PC 6500K only has one extra spike in red which will only help you grow more algae, for PCs 10k is what you would want. The only reason to include actinics is for a deeperwater appearance and fluorescence in certain colors. If you want to check my info just go to the store and grab some coralife PC bulbs. On the back of the box it has the spectrum charts for each bulb. The blue bulbs have only have blue but are missing all the other colors, while the daylight bulbs include the blue phosphors plus all the other colors .
RichConley
New member
Besl, make sure you look at the charts of wavelengths. If I remember correctly, 10K and 20K actually have large violet spikes, and 12-15K bulbs have blue spikes. Look at the bulbs though.
