Aquarium Lighting 101

J

jetskiking

Guest
Ok, I have been posting on this board a lot lately and have noticed this question keeps popping up. First off let me preface this by giving you some of my background and expierience in the hobby. I have close to twenty years in the hobby. I started off keeping fish only tanks then FOWLR tanks then reef tanks, which are my passion. I have done the vast majority of tank styles that can be done. I have run pretty much every lighting style out there including regular flourescents, VHO, powercompacts, T-5's and metal halides. I have also done a lot of research on each one of those technologies.
Anyway, let's get down to brass tax. There are a lot of options out there when it comes to saltwater aquariums. Choosing the correct lighting system for your needs is essential for your aquarium, and lets not forget your power bill. The most important thing is DO YOUR RESEARCH. Don't just take what somebody tells you on a computer from across the country as truth (many times it's not). Find out for yourself. This is typically the most expensive investment in your aquarium so don't be hasty.
MOST IMPORTANT, figure out what you want to keep.
A typical FOWLR needs very minimal lighting while a Reef can require a great amount depending on what corals you are keeping. I am going to approach this from an aspect of keeping reefs because that's where you will need the most lighting knowledge.
First off most corals need light to grow. They use photosynthesis to create food. The general concensus is that softies require the least, SPS require the most and LPS fall somewhere in the middle. This is true for the most part but just like anything there are exceptions. There are also non photsynthetic corals but that's another topic. Here is where it gets tricky, since corals use photosynthesis they only use the light that is available to convert to food.
When measuring the amount of available light for the corals to convert to food, WATTAGE MEANS NOTHING. The most acceptable method for measuring is called PAR (Photosynthetically Active Radiation). Retailers sell meters you can use to measure PAR. When you see the cost of a meter you will see why not al ot of people have them. Wattage per gallon is an outdated way of doing this and can only be losely associated with lighting of the same type. The reason I say losely is because even the same type of bulbs with the same wattage run on different ballasts can vary greatly in the amount of PAR they produce. We used the watts per gallon because thats all we knew then and I'm sure it can be associated with all the hit and miss successes of yesteryear.
Here are some of the most common lighting systems available and some info and my expierience with them.
Metal halides
- These are usually the most common choice when high lighting requirements are demanded. With a good ballast, bulb, reflector combo they can produce great amounts of PAR. They also penetrate deep into the water. A couple of the advantages are that they create a natural shimmer effect and they produce great results with little knowledge. A couple of the disadvantages are that they create a lot of heat and consume a lot of power. They also don't distribute the PAR as evenly as flourescents which is why a good reflector is key.
T-5 lighting
- This is a newer style of lighting than the halides. What a lot of people don't realize is that there are two different types. You have standard T-5 then you have T-5 HO. When using T-5 HO I have found that you can achieve pretty much the same PAR as a halide. This requires a lot more reseach and knowhow. I have also observed that the T-5 HO might even penetrate better and more evenly. A couple of the advantages of T-5 lightings tare that hey run a little cooler and the color spectrum is far more adjustable using multiple bulbs. A couple of the disadvantages would be that you don't get the shimmer and it takes a lot more knowledge on lighting to achieve the same results as with halides. Also keep in mind that without individual reflectors, T-5's waste a lot of light and will not be any more efficient than a power compact.
Power compact
- This is the least effective on generating PAR out of the three I mentioned. The advantage is that they are cheaper than the other options. These are generally used for softy/LPS tanks but are not very efficient for keeping SPS.
Disclaimer: This is my opinion and there are exceptions.
 
J

jetskiking

Guest
Originally Posted by meowzer
http:///forum/post/3127294
+1...good info
another advantage to the T5HO...would be price of the replacement bulbs
This is true but I have found that to create the PAR of a halide you need a bunch of bulbs which actually worked out as a wash for me.
 

spanko

Active Member
Originally Posted by jetskiking
http:///forum/post/3127322
This is true but I have found that to create the PAR of a halide you need a bunch of bulbs which actually worked out as a wash for me.
Interesting, do you have some data to show us on the PAR values of say a 150 watt halide compared to what would be and equivalent PAR using whatever number of T5 bulbs?
 
J

jetskiking

Guest
OK since it was requested I add some more on lets address some common questions and there answersHow often should I replace bulbs? This varies on the type and brand of bulb used A good rule of thumb is on halides and T-5's to replace every 12-18 months. On powercompacts replace every 6-8 months. Bulbs lose PAR overtime and at different rates over time. This can vary between brands and ballastbulb combo's.
How much light do I need to keep anything?
Well this boils Down to PAR again. I have found if you can achieve 100 par at the sandbed and somewhere around 400 mid tank you can keep whatever. The depth of the tank plays alot in this. I have also found that alot of people overkill their lights which is just a waste of electricity.
What color temp (K) bulbs should I use ?
Again this ties to par. The higher the K value of the bulb the more color that will appear to your eye (not actually in the coral ). Corals dont really use the blue , its more for us. the lower the K generally the more growth you will get. Remeber our corals contain symbiotic algea that thrives at lower K values. Its not so much PAR here in my opinion its more about giving the coral what it needs. This ties into the next question. Another important thing to remember is that the same K value bulb of different brands will look different.
Why do corals change color under different lighting?
As stated above our corals have a symbiotic relationship with algea. This algea is called zooxanthellae algae. It is also what gives our corals some of there awsome colors. Different types of these algeas thrive in different color spectrums. what you are essentially seeing is these different algeas becoming more or less prominent. Remember how I said that the lower the K the more the growth. I believe this is attributed to the algeas thriving and providing more food to the coral not so much on PAR. I have also noticed that when my corals display the most color is actually under lower K its just not as noticable to your eye. When I move corals out of my frag tank with a 10k into my display with 14k that is when they display the best colors.
Should I use a magnetic or electronic ballast on my halide?
there are a couple of things to remeber here. First is that typically a magnetic drives the bulb harder creating more PAR but will have a shorter bulb life. The other is that Some bulbs require certain ballast. This is where ANSI raitings on the ballast come into play. Do your research.
What is overdriving a bulb?
This is supplying more power to the bulb than needed increasing the output. This requires some research on the subject and also decreases bulb life.
Why do people run reverse cycles on fuge lights?
The is to keep the PH constant. By reversing the photosynthesis cycles you keep the CO2 levels more constant. CO2 makes PH drop.
 
Your thoughts on LED, not moonlight, and well Solaris is well say a dad issue.
Ive been reading about LED alot and in the future i am sure it will be big.
 
J

jetskiking

Guest
Originally Posted by spanko
http:///forum/post/3127328
Interesting, do you have some data to show us on the PAR values of say a 150 watt halide compared to what would be and equivalent PAR using whatever number of T5 bulbs?
I dont have any hard data at my fingers. But I can probably dig it up. The example I would use would be my 120. I run a 2x 250 metal halide on a 4ft 120 aga aqurium I make about 280 average par near my sandbed. I have another friend that runs the AGA 150. Keep in mind this is the same demension tank slightly deeper. He runs an 8 bulb T-5 HO setup with a few of those bulbs overdriven. We have very similar par value at the same depths. He is running 8-54 watt bulbs with some being overdriven. This puts him at almost identical wattage as me. At $20 dollars a bulb this equals $160 dollars to replace all the bulbs. This is actually $40 more than it costs me.
 
J

jetskiking

Guest
Originally Posted by fraggle rock
http:///forum/post/3127370
Your thoughts on LED, not moonlight, and well Solaris is well say a dad issue.
Ive been reading about LED alot and in the future i am sure it will be big.
LED technology is where the hobby is heading. I have seen the PAR readings in person. The PAR is great plus they use a lot less power. They are also alot more programmable. Problem right now seems to be getting over patent Issues. The LED's pretty much eliminate any of the drawbacks to other lighting systems. I will switch over eventually if someone will build a reliable one and the price drops. I think it stinks PFO (solaris) went under. I love their halides.
 

rigdon87

Member
Originally Posted by jetskiking
http:///forum/post/3127372
I dont have any hard data at my fingers. But I can probably dig it up. The example I would use would be my 120. I run a 2x 250 metal halide on a 4ft 120 aga aqurium I make about 280 average par near my sandbed. I have another friend that runs the AGA 150. Keep in mind this is the same demension tank slightly deeper. He runs an 8 bulb T-5 HO setup with a few of those bulbs overdriven. We have very similar par value at the same depths. He is running 8-54 watt bulbs with some being overdriven. This puts him at almost identical wattage as me. At $20 dollars a bulb this equals $160 dollars to replace all the bulbs. This is actually $40 more than it costs me.
hey jet i have the same tank 48x24x24 120gal and currently have a nova xtreme pro over it with 6x54w bulbs and individual reflectors,iam also running uvl and ati bulbs, but my question is do you think i have enough lighting to keep sps,if not what corals would you reccomend for my setup??what are your thoughts on this??
 
J

jetskiking

Guest
Originally Posted by Rigdon87
http:///forum/post/3127717
hey jet i have the same tank 48x24x24 120gal and currently have a nova xtreme pro over it with 6x54w bulbs and individual reflectors,iam also running uvl and ati bulbs, but my question is do you think i have enough lighting to keep sps,if not what corals would you reccomend for my setup??what are your thoughts on this??

You are probably fine with some SPS. You might want to stay away from really high light demand SPS like alot of torts, but they might do fine at the top of the tank. 6 bulbs seams to be the cutoff on SPS. Don't know if you are running a fixture or retrofit? If its a retro I would look into overdriving the bulbs. I do know the testing I have seen shows the bulbs you are running are great.
 

rigdon87

Member
Originally Posted by jetskiking
http:///forum/post/3127798
You are probably fine with some SPS. You might want to stay away from really high light demand SPS like alot of torts, but they might do fine at the top of the tank. 6 bulbs seams to be the cutoff on SPS. Don't know if you are running a fixture or retrofit? If its a retro I would look into overdriving the bulbs. I do know the testing I have seen shows the bulbs you are running are great.
thanks buddy.Yeah im just runnig the fixture with all aftermarket bulbs i dont really know what retrofit means but have seen it alot
 
J

jetskiking

Guest
A retrofit is basically all the parts out of the casing so it can be installed into an existing hood. The reason I mentioned the retro is because it makes it alot easier to rewire and replace parts to overdrive. You can do it on a stock fixture but it makes it harder. I would try some lower light SPS such as Monti's, digi's, birdsnest and see how they do.
 

truperc

Member
Originally Posted by jetskiking
http:///forum/post/3127278
Also keep in mind that without individual reflectors, T-5's waste a lot of light and will not be any more efficient than a power compact.
halides and T-5's to replace every 12-18 months
I would imagine with individual reflectors you would lose out on some of the blending of light colors if you are keeping different kelvin bulbs.
I also thought halides had a significant drop in PAR after 6 months. I had never heard halides and T-5's having the same replacement timetable.
These are questions more than statements.
 
J

jetskiking

Guest
Originally Posted by TruPerc
http:///forum/post/3128739
I would imagine with individual reflectors you would lose out on some of the blending of light colors if you are keeping different kelvin bulbs.
I also thought halides had a significant drop in PAR after 6 months. I had never heard halides and T-5's having the same replacement timetable.
These are questions more than statements.
The individual reflector on each bulb directs the light that is realeased at the top of the bulb around the bulb more efficiently. With a one reflector across all the bulbs actually block the light being reflected. What you stated is true though. This is also why it important on t-5's to do research on the placement of each bulb in the fixture for optimum color blending the advantages.
On the halides it really depends on the bulb. I know with the bulb I run, there is a fast drop in PAR the first few months then they level out. Other brands of bulbs do this at different rates. It can Normally take anywhere 12-18 months for the halide to drop in PAR enough to have an effect. This depends on your lighting cycle, brand of bulb and ballast of course. The T-5's have a little less testing done out there but the concensis seams to be about the same time table.
 
Ok I have a question, I have a 55g and am looking at lighting. Is 4 bulbs that equal 440w with reflectors way overkill? Or would 2 bulbs which are
220w with reflectors work? I was thinking of maybe eventually getting some SPS and clams, so I would like lights that give me the most options but won't break the bank.
 

kristi518

Member
Originally Posted by jetskiking
http:///forum/post/3127372
I dont have any hard data at my fingers. But I can probably dig it up. The example I would use would be my 120. I run a 2x 250 metal halide on a 4ft 120 aga aqurium I make about 280 average par near my sandbed. I have another friend that runs the AGA 150. Keep in mind this is the same demension tank slightly deeper. He runs an 8 bulb T-5 HO setup with a few of those bulbs overdriven. We have very similar par value at the same depths. He is running 8-54 watt bulbs with some being overdriven. This puts him at almost identical wattage as me. At $20 dollars a bulb this equals $160 dollars to replace all the bulbs. This is actually $40 more than it costs me.
I was curious how far from the water you had these lights placed. I have a 125gal 6'Lx20"tall and still have my old 48" 2x 250MH with 2x T5.
I'm trying to decide how far off the water to place my fixture. I want to have it far enough to reach more of the tank(sides) but low enough for the corals. I'm thinking I might need to pick up some more lighting for the ends to make up for it, but the wallet thinks otherwise.
 
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