Lighting - How much light is right?

[gnatp2]

So I've been on a quest to get better colors out of my corals and had moderate success, but I do have a ways to go. My current focus of improvement is the lighting of my tank. I recently went with a new sump as well as a new 150W MH Icecap pendant for it. I have placed a couple frags down in my frag grow out area and have noticed that they "lighten up" significantly (it appears to me that much of the brown zooxanthaellae go away and either the coral is bleaching or starting to show better colors).

On my main tank I am using a 400W dual PFO ballast with 2 EVC 10K bulbs hooked into spider reflectors. I also have 2 T5 actinic bulbs as well.

My question is...... How much PAR or PPFD should my sps corals be getting? In my sump it seemed to me that they were getting significantly MORE lighting than my main tank. Well, I went out and bought a light meter to confirm this suspicion. My sump light is producing 1200 PPFD (reading taken 4" under the water) while my main tank lighting is only producing 300 PPFD (also taken under 4" of water).

I've read that during the summer at noon, the sun produces around 2000 PPFD and 1500 PPFD during the winter. I've also read from Sanjay's website that most bulbs produce 90 PPFD or so.... Yes, no typos in these numbers which is why I'm confused. I've searched around but found no answers so far on what the ideal PPFD is that should be hitting corals. Obviously the answer will be different coral by coral, but I'd like to get a general idea.

Can anyone educate me?
Nate

 

[gnatp2]

Hello people???? This should be interesting. Lets get it going.

 

[Deanos]

How much light?

Water flow is more important for corals than light, Part V

Water flow is more important for corals than light, Part IV

Water flow is more important for corals than light, Part III

Water flow is more important for corals than light, Part II

Water flow is more important for corals than light, Part I

 

[ShaunW]

First a quick question: Is the values you give for the sun's PPFD rating at a particular depth?

Corals like nutrients! They can make most of it through photosynthesis using the zoox to generate amino acids. Bacteria living in the tissue and Ca carbonate skeleton can also undergo nitrogen fixation, generating nitrate, glutamate and glutamine. These building blocks for biosynthesis, when available, cause the coral to grow (I am mostly talking about SPS). So the answer to your question depends on many factors and how they all are available for the coral to use. These factor include and a not limited to: zoox presence at proper density, symbiotic bacterial presence for N-fixation, bacterial plankton and phytoplankton availablility, Ca and carbonate concentrations, quality of water for light penetration, and flow to remove waste and bring nutrients/food. So light while extrememly important is one factor of many. Having lower par light BUT high nutrient availability that can be directly bioassimilated can cancel each other out such that the former will compensate for the decreased photosynthesis of the zoox.

 

[kimoyo]

Hey Nate,

Your probably not going to get a lot of answers because this is a tough question. If your concerned with colors I wouldn't worry too much about par. I would worry more about filtration and then about the wavelengths of light hitting the tank. I started looking around about this early last year, read a few days but didn't have time to really go deep into it. Plus, we all keep a lot of different species in the tank so how one coral reacts to certain light is not necessarily how another coral will react. I've seen a lot of Japanese tanks which really try to hit the corals with different colors of light. So my advice is get get some lumenarcs, go down to 250 mh so your not wasting electricty and make sure your filtration is the best it can be. Here's a post I made last year kinda on the subject.

The thing is, its not all about par when it comes to growth and coloration because par is really just measuring the intensity of light emitted. While par is important I think the spectrum is important also.

This is a quote posted by mojoreef in this thread, Lets talk about ~Lighting~ (a very good read).

>Pocilloporin primarily absorbs green/yellow (550-600 nm) light along with some upper UV-A . it emmits a orange/red
>highly fluorescent pocilloporins primarily absorbs light from 310 to 380 nm (UV-B and UV-A) and then fluoresces this as light from 400 to 470 nm (violet/blue).
>highly fluorescent pocilloporin primarily absorbs light from 380 to 470 nm (UV-A, violet and blue) and fluoresces light from 475 to 520 nm (blue and green).
>third type of highly fluorescent pocilloporin primarily absorbs light from 430 to 490 nm (violet and blue) and fluoresces light from 490 to 540 nm (green/yellow).
>Yellow fluorescing pocilloporin primarily absorbs light from 440 to 500 nm (blue) and fluoresces light from 520 to 620 nm (green, yellow and orange).
>Red/Orange Fluorescing pocilloporin that primarily absorbs light from 500 to 540 nm (green) and fluoresces light with wavelengths that are primarily orange to red.

To understand this just read that thread, but fluoresces basically means the color you see. So if you take into consideration coloring highest par doesn't mean its the best for the corals. To get some good fluorescence you want to be hitting the corals with 310-380 light. Take a look at this graph from Sanjay website (don't worry about the axis titles, all this basically means is the higher value the more light at that wavelength).

Whereas the xm has the highest par (great for growth), you can see how it lacks in that fluorescence range but the ushio (lower par) doesn't.

And here's a graph comparing the ushio with the blv.

Very similar but the ushio has a slightly higher par. Thats why (and with its CCT) I'm somewhat surprised its more yellow. But the blv is looking like the way to go, unless the reeflux has a similar spectrum.

 

[gnatp2]

Deanos, thanks for the links. I read through the first one so far and it was exactly what I was looking for. It seems that overall 200-400 Par is the zone that works best for sps corals.

First a quick question: Is the values you give for the sun's PPFD rating at a particular depth?

I really don't know how that reading is taken which is why I am confused. I'm only guessing that the 2000 PPFD statement that I've been reading is not at any depth whatsoever but I really don't know. Here's the quote from the first Deanos link: "Photosynthetically Active Radiation (PAR) in units of micromole photons per square meter per second (?mol?m??sec; as a point of reference, sunlight at noon on a cloudless day in Hawai?i can be as high as 2,200 ?mol?m??sec )."

Having lower par light BUT high nutrient availability that can be directly bioassimilated can cancel each other out such that the former will compensate for the decreased photosynthesis of the zoox.

My tank has had <1 Nitrates for months and .03 phosphates for about 1 month now. I have finally started to see improvement in colors for the corals that are higher up in the tank in the past 2 weeks. The corals that are in shaded or lower regions of the tank have not shown improvement though. They grow well, but have brown colors. I'm thinking that this is an example of your statement about high nutrient availability but low par due to the large populations of zoox on the corals to compensate for the lack of light. (Pls clarify if I am misunderstanding you)

Also I would like to say that I agree that there are MANY other important factors (nutrient levels, spectrum, etc...) that are extremely vital as well for good coral growth and coloration, but it seems that an obvious and simple factor has got to be a reasonable amount of PAR hitting the corals. Many times the basics get overlooked.

My next goal will be to test a few other tanks that have good coloration and see if anything interesting pops up.

Nate

 

[Slamajamajama]

good info here...

 

[Wes]

in my limited experience with SPS, the thing that effects my colors the most is unstable alkalinity. For example if i make an adjustment to my Ca Alk dosage and don't go extremely slow, the colors fade.

You said you are having problems with frags fading in the sump correct? I imagine you Ca Alk is being dosed directly into the sump? Not much water volume in comparison to the entire system, Alkalinity certainly could swing quite a bit in the sump before it is circulated throughout your system. Just a theory.

 

[gnatp2]

in my limited experience with SPS, the thing that effects my colors the most is unstable alkalinity. For example if i make an adjustment to my Ca Alk dosage and don't go extremely slow, the colors fade.

You said you are having problems with frags fading in the sump correct? I imagine you Ca Alk is being dosed directly into the sump? Not much water volume in comparison to the entire system, Alkalinity certainly could swing quite a bit in the sump before it is circulated throughout your system. Just a theory.

Wes, good advice about stability. There is an excellent thread on this board about the importance of stability in a reef tank. I am dripping my 2 part into my sump, but it is in the return chamber which should solve any issue with concentrated dosing right next to corals

And to clarify about the frag colors in my sump... It isn't that I have good colors in my main tank and bad colors in my sump, it is the case that frags in my sump have lost much of their brown color because of more intense lighting down there. I'm not happy with the colors in either area.

Nate

 

[Tim]

Hay Nate do you want to come up to Rockland to check the par in my two tanks? LMK Tim......

 

[kimoyo]

Also I would like to say that I agree that there are MANY other important factors (nutrient levels, spectrum, etc...) that are extremely vital as well for good coral growth and coloration, but it seems that an obvious and simple factor has got to be a reasonable amount of PAR hitting the corals. Many times the basics get overlooked.

Nate,

If you blast corals with light you can cause oxidative stress which leads to zoox breakdown and loss. About a year ago it was pointed out to me by ebby and solbby that this isn't a good thing or a healthy state for any living organism. There is a line but blasting corals with light to make up for an increased zoox population is not a good idea.

Going back, sunlight produces white light, basically a whole bunch of different wavelengths of light. But when sunlight hits water, the water molecules actually absorb the energy converting it into heat, except for the bluer spectrum. Why is this important?? well most corals seem to like blue light, probably because its what they get. Its also why you see a lot of people using 20K bulbs.

So what is that you see when your looking at the colors of corals? It's either reflected or fluoresced light, either the coral took in the light and spit it back out or it took in the light, took a little of its energy and spit it back out at a different color and its a quantum process. So why is this important?? there's two topics your talking about here. One is what the coral needs to survive and what the coral needs to have great color. You don't need a bunch of par to have great colors, its the opposite, blasting corals with a huge amout of par can be bad for them. Whats important is that you have a low nutrient system where the zoox don't eat a lot and the corals get fat and turn brown. Then you don't have to blast them with light so they become bulimic throwing up the zoox. And at the same time you need the right spectrum of light hitting the corals so they flouresce these beautiful colors. Even more than that, when you get to a certain par, corals shut down and stop doing photosynthesis. Any of the light the coral is not using is just heating up your tank.

Ask yourself, why are you using 400W 10K bulbs to get so-so colors when others can use 150W 14K bulbs and get amazing colors?

 

[gnatp2]

I got rid of my dual 400W PFO ballast, spider reflectors and EVC bulbs. I switched it over to 2 400W coralvue ballast with lumenarcs using reeflux bulbs. The tank looks a bit darker to me overall. BUT when testing with my light meter, the par in the tank is at least double what it was before. While re-doing my hood, I broke one of my t5 bulbs, so I'll be waiting a couple days before putting those back in there. I'm hoping that the newly added par will improve the coral coloration. I'll hopefully post in a week or two with any results.

If anything, I at least upgraded to pretty pink ballasts.

Nate

 

[kimoyo]

Good stuff on the lumenarcs!

The reason the tank seems darker is because light diverges/spreads and the lumenarcs focus the light better than most other reflectors in the hobby. What color bulbs you using?

If you keep working at it and hopefully get your nutrients low, your corals will start to fade and you'll need to raise your reflectors, which is why I suggested 250's. It will just be too much light and raising the light will help to spread the light outside the tank into the room and let the light react more with the air. It happened to a lot of people on this board when they switch over to barebottom and got low nutrient systems. They wound up cutting their lighting cycles down (with 250's) because their corals were getting pale.

Goodluck with it though!

 

[gnatp2]

Thanks Paul. Strange thing is that I've had a low nutrient system for at least 2 months now. (nitrates have always been <1 for at least 6 months and phosphates have been <.03 for 2 months. around .06-.1 the 3 months before that).

Anyway, we'll see how it goes!
Nate

 

[kimoyo]

Thanks Paul. Strange thing is that I've had a low nutrient system for at least 2 months now. (nitrates have always been <1 for at least 6 months and phosphates have been <.03 for 2 months. around .06-.1 the 3 months before that).

That is not a low nutrient system!

If you get a zero reading on your phosphates test you still have phosphates in your tank.

Ask jackson6475 what a low nutrient system is or do a search on the forum and you'll find tons of info. There were a bunch of threads about this last year.

 

[gnatp2]

i use a hanna meter. i read 0 on the salifert piece of crap.

i don't know of anyone who consistantly gets <.03 in the hanna besides chris.

 

[kimoyo]

i use a hanna meter. i read 0 on the salifert piece of crap.

i don't know of anyone who consistantly gets <.03 in the hanna besides chris.

Having a low nutrient system isn't a necessary thing, I just know you have mentioned you wanted your nutrients lower before. There are many different ways to do things. That being said, there are a lot of reefers who get 0 on the hanna meter but that doesn't matter. The only thing a hanna meter or salifert phosphate test can do is give you a starting point. They tell you nothing about organic phosphates which is what ultimately matters and varies with every tank regardless if you get a zero on a test. Also, nitrates play a role and those need to at least be zero on the hobby test also.

Seriously, there are a lot of good threads from last year in this forum that go over this stuff if your interested in it. Just do a search.

 

[kimoyo]

How much light?

Water flow is more important for corals than light, Part V

Water flow is more important for corals than light, Part IV

Water flow is more important for corals than light, Part III

Water flow is more important for corals than light, Part II

Water flow is more important for corals than light, Part I

Nate have you read these article yet? Here's a quote from part III,

"Having a better knowledge of the environmental factors that make corals healthier can help aquarists grow corals faster and it might help us to understand the care requirements of still difficult species such as Goniopora and Dendronepthya. More importantly, a better understanding of the synergy between water flow speed and lighting intensity can help aquarists make better informed decisions about the equipment they should employ for their aquariums. Coming back to one of the first things I discussed in this article series, aquarists often put much more effort into considerations for lighting than water flow. As you can see from figure 7, if an aquarists provides very high light intensities but fails to deliver an equivalent water flow speed, instead of benefiting it is more likely that their corals will suffer from photoinhibition stress. The excessive lighting equipment will not yield the desired increase in growth rate but instead it will likely cause an increased heat input to the aquarium, increased algae growth and a considerable waste of money and energy. If you take nothing else from this article series just remember that:
The more light a coral receives, the more flow it will need"

What's your flow in your tank like now? Have you increased it as your increasing lighting?

 

[jackson6745]

So I've been on a quest to get better colors out of my corals and had moderate success, but I do have a ways to go. My current focus of improvement is the lighting of my tank. I recently went with a new sump as well as a new 150W MH Icecap pendant for it. I have placed a couple frags down in my frag grow out area and have noticed that they "lighten up" significantly (it appears to me that much of the brown zooxanthaellae go away and either the coral is bleaching or starting to show better colors).

On my main tank I am using a 400W dual PFO ballast with 2 EVC 10K bulbs hooked into spider reflectors. I also have 2 T5 actinic bulbs as well.

My question is...... How much PAR or PPFD should my sps corals be getting? In my sump it seemed to me that they were getting significantly MORE lighting than my main tank. Well, I went out and bought a light meter to confirm this suspicion. My sump light is producing 1200 PPFD (reading taken 4" under the water) while my main tank lighting is only producing 300 PPFD (also taken under 4" of water).

I've read that during the summer at noon, the sun produces around 2000 PPFD and 1500 PPFD during the winter. I've also read from Sanjay's website that most bulbs produce 90 PPFD or so.... Yes, no typos in these numbers which is why I'm confused. I've searched around but found no answers so far on what the ideal PPFD is that should be hitting corals. Obviously the answer will be different coral by coral, but I'd like to get a general idea.

Can anyone educate me?
Nate

Nate, I have no idea on the best PPFD levels, IMO this makes very little difference in color as long as you have decent lighting. If this an issue about coral colors I can tell you that the overly yellow 400w EVC 10ks is not helping your situation. 2 actinics is not enough to offset these bulbs. With lighting that strong you will have a lot of coral acclimating to do, and as you know not all corals will respond the same way. This lighting will kind of wash away your colors.

My advice to you would be to copy what works. These are undisputed "best" lighting systems of great tanks. Why reinvent the wheel? Copy what works.

250w 10kXM Icecap ballasts + 2-4 T5 or VHO actinics i.e. Pecan2phat, JBNY, Calireef, lousimustdie etc..(I used BLV's insted of the XM'S)

400w Reeflux 10k Icecap or coralvue ballast + 2-4 actinics. i.e. Tony Acropora, Stan Mucha, MR's current TOTS Twinreef ( I used this lighting for 4 months)

400W Radiums HQI ballast + actinics. There are MANY MANY tanks using this lighting and I never heard one bad thing besides the expense of bulb replacements.

If you can't get color using these lighting systems then lighting is not the issue.

HTH FWIW

 

[Deanos]

If you can't get color using these lighting systems then lighting is not the issue.

:agree: