Nutrients or Whole Tank Nutrition?

[Brandon McHenry]

I think that everybody knows that I am in the "availability over residual levels" camp. Feed a lot, export a lot and keep residuals reasonable, but low (not zero). Ammonium and ammonia are the prize to get nitrogen to SPS, not nitrate. A little bit of P is good, but not too much.

2sunny has a wonderful tank and has also posted lately about having very low residual levels but high throughput/availability.

I think that most people who have had N and P raise without dosing on the back end have seen the effect of more availability, not from having higher residuals. Their tanks would be just as good with the same feeding, but more fuge (or whatever). In nearly all cases, the availability does the heavy lifting.

Regarding low detection levels of nitrate, this is hard... my tank shows "clear" on test kits, but I have .1 to .2 on an ICP test. .1 to .2 is not zero and it is a world away. True zero is an issue, but you nearly always have to use chemicals or media to get there. My sandbed, which can chew through nitrates like crazy, always leaves enough to keep the equilibrium going forward.

Having higher levels of N and P can do other things for the tank, if you need them. They can poison dinos, matting bacteria and diatoms at levels that are not so high for most corals - some acropora will suffer at these levels, but most people just do with them and chalk them up to "too hard," which is smart. They also slow down coralline growth at higher levels, which is a plus to some. This is not the same thing as being ideal for SPS... but it does need to be incorporated into a whole-tank strategy.

You can get some deeper saturation with nigher N and P levels on some corals, but not others. Some acropora will have less differentiation in the colors if they are multi-colored, but not all. Most acropora with different colored growth tips will look better with lower N and P, but, again, not all.

I wish that more people understood that N and P are not food and are building blocks. I wish that more people understood that SPS cannot process nitrate without first turning it back into ammonia/ammonium at quite a cost of energy to the coral (we are in the SPS forum after all even though a few other corals can use no3 straight up). I wish that more people understood that dosing P is just binding more to your rock and sand with a very small amount ending up in the water column and that this could be a huge problem down the road. I wish that more people understood that lighting with the zoox making sugars is what truly feeds the coral and if they spend as much time worrying about wider spectrum (quality) over N and P that their corals would likely be a lot happier in most cases.

I do not care for a lot of BRS videos because they are more infomercial than real science, but check out their video on Zeovit, which is a heavy import and heavy export system - like 1:45 to about 3:30. They basically say that the tank has more "nutrients" going through it than any other tank that they have, but the backend numbers stay low. This is the goal, IMO.

I hate that they say Ultra Low since this tank is probably just like Natural Seawater and not Ultra Low. You usually have to use chemicals and media and not feed a bunch to get Ultra Low. IMO, natural seawater levels are just natural, not low or ultra low.

BTW - I do not recommend Zeo unless you are super into dosing and testing A LOT. However, it is an example of how high availability and low residuals do a great job.

Residual levels are the easiest - the values on the test kits of your nitrate and phosphate. These get focus since people can put numbers to them. They are also fools gold in most cases, like so many other simple things in our life... light weight of a human where one person weighing 225 is nothing but pure muscle and athleticism but is a lot of fat on others.

Availability is what what "in process" that the corals can use before it becomes nitrate at the end of the cycle. This is mostly in the form of ammonia/ammonium that the fish (and other things) have as waste product. This is nearly impossible to measure. It is a little more complicated than this, but this will do for now...

Bacteria can handle the no3 on the backend if you have a lot of good rock or sand that can harbor anoxic bacteria - these convert nitrate into nitrogen gas and keep no3 at good levels. Sometimes rock alone is not enough, but sometimes it is - just depends on the tank and the maturity of the rock. A 3 inch sandbed can usually take care of no3 in nearly all situations if it is mature and mostly left alone - there is some maintenance that is needed periodically which is more than we need to get into here. The new paradigm of starting tanks with sterile rock and sand mean that it can take years for them to act like real live rock from the ocean - their pores are usually bound with terrestrial organics and the bacteria have no place to live.

Phosphate is harder since nothing in the tank converts it to gas. Aragonite (sand and rock) binds phosphate and will act like a buffer (good) at low levels, but can also act as a reservoir (bad) at higher levels. You will need to grow macro algae, use GFO or other media to keep it low - water changes work, but are not efficient to lower P. It is important to understand the relationship between aragonite and phosphate and how much that it can bind - nearly all dosed phosphate ends up in the rock and sand.

There is another way that corals CAN gets some building blocks, but it is not clear that it happens in our tanks. Amino Acids. Amino Acids can be absorbed through SPS skin. This does not mean that dosing bottles Amino Acids will work. They are also used by nearly all single cell organisms on surfaces and in the water column. First, we have no idea which aminos are in a supplement - some are better than others. Second, it is losing math equation for the SPS to get some... the bacteria, single cell algae and other microscopic things in the water column and on the surfaces or the sand and rock will all want the amino acids that you are trying to give to your SPS. It is not likely that the SPS get much. While it is not likely that Amino Acid supplements do much for the SPS, the also do not seem to really hurt and maybe some of those microorganisms get caught by the corals (not in their polyps, but in their slime coat where they are dissolved and their energy/nutrients gathered). In the end, it probably does not hurt to dose some Amino Acids if your residual levels of N and P are in control, but you are likely hurting if your N and P are already high.

You can put me down as one of the supplement skeptics that have not ever seen one that did much in almost three decades of reefing. I am not saying that I have seen or used them all, but I have tried a bunch. I have no use for any of them and I can say with almost certainty that none of them are necessary at all. To each their own...

I also forgot to mention that hosts can recycle most things like N, P and aminos once they have gathered them for their symbionts. This means that it is likely that corals only need new stuff to grow, not just to maintain - this helps to explain why just a trace of building blocks are necessary. This has been debated by some, but also highly supported by others including some highly respected marine PhD folks. In addition to this resource below which talks about dinoflagellates inside of hosts, this recycling is mentioned in a few coral books that I own.

Nitrogen cycling in corals: the key to understanding holobiont functioning?

Corals are animals that form close mutualistic associations with endosymbiotic photosynthetic algae of the genus Symbiodinium. Together they provide t…

www.sciencedirect.com

As always @jda I appreciate the depth of knowledge you bring to these conversations. I think you make lots of very valid points and provide your reasoning. I have seen @2Sunny ‘s tanks here and agree that the results he gets from a high throughput system are inspiring. I feel, like you do, that most starving coral situations could be better solved through increased feedings or more fish. The result you want with your tank has to match what is being put in. I also think that feeding the tank as a whole is part of what makes these heavy in heavy out systems successful. Everything in the tank from bacteria to fish has a chance to eat and acquire the proper nutrition at one point in the cycle. I also liked the way BRS explained the zeovit system. Too many people think that it’s as simple as stripping the tank of all N/P, but it’s so much more than that with the addition of all the food and elements in very controlled amounts. Overall I think some of the most successful full-blown acropora (not just SPS) reefs that I have seen have been simple systems, with tons of fish that get fed a lot and a decent skimmer and a big ball of chaeto. I’ve tried to overcomplicate my system in the past but I eventually went back to the basics of what I know best and my tank has thanked me for it.

P.S. I know it’s the time of year for wish lists but that’s one big list!;Hilarious

 

[Reefahholic]

I think low levels of N&P are good to have. I’ve experienced more algae growth once I let the tank drift over 0.2 ppm PO4, but this really just depends on the tanks maturity, lighting, flow, and as you know there are so many other factors. I try to target a range from about 0.05 to 0.15ppm. I think coral nutrition (if you wanna put that separately) can be very important for lower nutrient tanks. Overall I feel like most corals generally do better with good nutrition. I’m just too busy to feed a lot of the time. As far as NO3 I think it’s extremely important to keep a detectable level. My tanks do best when I keep NO3 at about 3-12ppm range. At different numbers in that range the tank does well. I think it really just depends where your PO4 level is at as I haven’t figured out the magical pattern yet. I’ve documented when the tank looked it’s best and grew the most and it was never exact numbers it was always with those ranges I listed.

When you test seawater, the levels are very low because the ocean is the most established reef tank there is. So reefers tend to try and keep their numbers ultra low, but think of all the uptake that happens in a natural reef or in the ocean in general. You see this very same thing in a lot of heavily stocked Acropora reefs. They have wall to wall huge colonies and you say...”what are your N&P numbers” and they say....”Ohh I don’t test, but they’re always zero.” The colonies are literally sucking the N&P and overall nutrition out of the water rapidly. Therefore the hobby grade test kit gets zero results.


You could never setup and beautiful thriving packed Acropora reef w/o their being some nutrients in the water. They will just die.

For example if you set up a 120/G. Got the corals growing and took away all the fish, inverts, etc..and never fed the tank at all. It might last a short time,but eventually colors will begin to fade and the corals will starve resulting in STN/RTN.

 

[Reefahholic]

You guys might find this interesting. Just skip to the end if the testing bores you.

 

[Brandon McHenry]

I think low levels of N&P are good to have. I’ve experienced more algae growth once I let the tank drift over 0.2 ppm PO4, but this really just depends on the tanks maturity, lighting, flow, and as you know there are so many other factors. I try to target a range from about 0.05 to 0.15ppm. I think coral nutrition (if you wanna put that separately) can be very important for lower nutrient tanks. Overall I feel like most corals generally do better with good nutrition. I’m just too busy to feed a lot of the time. As far as NO3 I think it’s extremely important to keep a detectable level. My tanks do best when I keep NO3 at about 3-12ppm range. At different numbers in that range the tank does well. I think it really just depends where your PO4 level is at as I haven’t figured out the magical pattern yet. I’ve documented when the tank looked it’s best and grew the most and it was never exact numbers it was always with those ranges I listed.

When you test seawater, the levels are very low because the ocean is the most established reef tank there is. So reefers tend to try and keep their numbers ultra low, but think of all the uptake that happens in a natural reef or in the ocean in general. You see this very same thing in a lot of heavily stocked Acropora reefs. They have wall to wall huge colonies and you say...”what are your N&P numbers” and they say....”Ohh I don’t test, but they’re always zero.” The colonies are literally sucking the N&P and overall nutrition out of the water rapidly. Therefore the hobby grade test kit gets zero results.


You could never setup and beautiful thriving packed Acropora reef w/o their being some nutrients in the water. They will just die.

For example if you set up a 120/G. Got the corals growing and took away all the fish, inverts, etc..and never fed the tank at all. It might last a short time,but eventually colors will begin to fade and the corals will starve resulting in STN/RTN.

Yeah when it comes to algae I think there are too many factors to account for to just point fingers at N/P so I’m on board with you for that. And I do think that the hobby should consider coral nutrition as more than just nitrate and phosphate. Like you said, the oceans as well as mature SPS tanks have very low N/P but there is so much food moving through those systems that everything is always feeding in some form and meeting their nutritional requirements. I think you bring up a very interesting point regarding this hypothetical tank. I certainly agree that if you ripped all the fish out of a mature reef and didn’t feed anything, the coral would eventually perish. I would argue, however, that in that same fishless tank with no food, that simply dosing nitrate and phosphate would not sustain the reef either. I think this plays to my point that there is so much more to keeping coral healthy than the two measures of nitrate and phosphate.

 

[Brandon McHenry]

You guys might find this interesting. Just skip to the end if the testing bores you.

Very interesting video. It doesn’t totally surprise me that there would be a detectable level of phosphate that close to shore and human populations.

 

[Reefahholic]

Very interesting video. It doesn’t totally surprise me that there would be a detectable level of phosphate that close to shore and human populations.

You can always tell where humans have been. Algae is on the rocks, piers, boat ramps, etc.

If you’ve every visited a local duck pond at a city park...you’ll see exactly what excess nutrients do. Hundreds of people feeding the ducks daily sure ruins the water quality.

 

[Brandon McHenry]

You can always tell where humans have been. Algae is on the rocks, piers, boat ramps, etc.

If you’ve every visited a local duck pond at a city park...you’ll see exactly what excess nutrients do. Hundreds of people feeding the ducks daily sure ruins the water quality.

Tell me about it! Lol. I work at a place that does a lot of research on human impacts on the ocean, especially nutrient pollution.

 

[jda]

Coral Food: sugars from the zoox and any carbon in an organism that they can catch. This is energy.

Building Blocks: N and P (and other things). These are not energy. They are used in organic organic tissue.

More sugars from the zoox means more energy and faster growth. More N and P does nothing over "enough" as long as you are not growth limited. Think of sugar as a mason and N and P as bricks and mortar... your masons can only work so fast, but if you get more masons, then you can work faster as long as they are working slow enough that the old layers of laid bricks have cured and can support the new layers (you can only go so fast). The bricks and mortar need to be supplied in small increments all of the time or else they would overrun the place with mess and the mortar would cure before you could use it. You cannot have massive amounts of brick laying around or else nobody could move and work... and you cannot make all of the mortar at once or else it will go bad. Not having any bricks and mortar is bad.

N and P are not energy or food. When people say "feed your corals, dose N and P" they are wrong.

 

[jda]

I think that it would help if people called N and P "building blocks" instead of "nutrients." Although technically a nutrient since nutrient is defined as "a substance that provides nourishment essential for growth and the maintenance of life" this is pretty broad. I am technically a substance and so are the electrons that run through the AC in my house that power the pumps and lights.. so I guess that I am a nutrient too and so is the electricity since we both provide nourishment in some form. I know that this is argumentative, but treating all things as "nutrients" is as dangerous as saying that all "coral" are the same.

Anyway, it would be easier for people to understand that light=>zoox=>sugars=>food vs N&P=>tissue creation.

Also, some N and P is needed for not only growth, but also some repair. This is where the host recycling things like N, P and Aminos comes in where this lessens the effect on the coral in periods where new/fresh N&P is not available. Super low levels of N and P are not good and are growth limiting, but they should not lead to death... at least not for a while (nothing lasts forever). Once you understand what N and P do (not energy), then it is easy to see why this is true. This is why it is especially bad when corals expel their zoox during bleaching events in the ocean - they expelled all of those building blocks that they literally spent a lifetime obtaining. Most coral don't ever get them all back again.

It is not likely that low levels of N and P killed somebody coral quickly... it was most likely something else and the N and P got blamed since somebody can test for it. The answer is a lot more complicated, but it takes work to figure this out.

 

[joshwaggs]

Coral Food: sugars from the zoox and any carbon in an organism that they can catch. This is energy.

Building Blocks: N and P (and other things). These are not energy. They are used in organic organic tissue.

More sugars from the zoox means more energy and faster growth. More N and P does nothing over "enough" as long as you are not growth limited. Think of sugar as a mason and N and P as bricks and mortar... your masons can only work so fast, but if you get more masons, then you can work faster as long as they are working slow enough that the old layers of laid bricks have cured and can support the new layers (you can only go so fast). The bricks and mortar need to be supplied in small increments all of the time or else they would overrun the place with mess and the mortar would cure before you could use it. You cannot have massive amounts of brick laying around or else nobody could move and work... and you cannot make all of the mortar at once or else it will go bad. Not having any bricks and mortar is bad.

N and P are not energy or food. When people say "feed your corals, dose N and P" they are wrong.

What are your thoughts on Phytoplankton and zooplankton dosing? I saw a study that showed coral may be feeding primarily on bacteria that gets stuck in the low flow areas of the colony. So, that should work the same for phytoplankton and zooplankton, right?

 

[jda]

I will just keep my thoughts to what happens in our tanks.

First, plankton and bacteria are not the same. The bacteria can be caught and assimilated in the slime coat with nearly all energy transferred. Plankton needs to be caught and digested by a polyp. Some of this is a math problem of surface area and contact chance.

Bacteria is easy since it appears that the catching and energy transfer is total and efficient.

Plankton is harder since it is unknown that anything that we offer them has enough energy to make the catch and eat worthwhile. It has been always "known and assumed" that phyto is not right for most SPS (at least since I have been reefing since the early 1990s) - this is always subject to change like all science, but there is a lot of evidence that phyto is not right. For zooplankton to work, it needs to probably be live and also the correct size (nobody really knows and each coral seems to be different) and then has to be teeming with nutrition to make the catch and digest worthwhile. Nobody know if any of this is correct.

We met a marine biologist from the Coral Sea that told us that the clean-water acropora reefs in the area did not get nary any supplemental feedings except under extreme circumstances, but the shallower reefs and lagoons more near to the shore would get some. Light delivered nearly all the energy to the acropora in these clear-water areas.

In the end, dosing phyto or live zoo probably does not hurt anything as long as you can export on the back end and N and P residuals do not rise (kinda like Aminos), but I personally do not think that it does what people think that it does for the corals. Some phyto and zoo might really help some pods and stuff, which can be good - so phyto to the whole tank is a different calculus than phyto for acropora. Just like other types of dosing, it is certain that it is not necessary whatsoever since there are just too many long-lived thriving tanks that don't add any.

I think that if everybody just assumed that light was the only energy, then they would be better off. Any benefit from a feeding could just be additional.

 

[Brandon McHenry]

Coral Food: sugars from the zoox and any carbon in an organism that they can catch. This is energy.

Building Blocks: N and P (and other things). These are not energy. They are used in organic organic tissue.

More sugars from the zoox means more energy and faster growth. More N and P does nothing over "enough" as long as you are not growth limited. Think of sugar as a mason and N and P as bricks and mortar... your masons can only work so fast, but if you get more masons, then you can work faster as long as they are working slow enough that the old layers of laid bricks have cured and can support the new layers (you can only go so fast). The bricks and mortar need to be supplied in small increments all of the time or else they would overrun the place with mess and the mortar would cure before you could use it. You cannot have massive amounts of brick laying around or else nobody could move and work... and you cannot make all of the mortar at once or else it will go bad. Not having any bricks and mortar is bad.

N and P are not energy or food. When people say "feed your corals, dose N and P" they are wrong.

I think that it would help if people called N and P "building blocks" instead of "nutrients." Although technically a nutrient since nutrient is defined as "a substance that provides nourishment essential for growth and the maintenance of life" this is pretty broad. I am technically a substance and so are the electrons that run through the AC in my house that power the pumps and lights.. so I guess that I am a nutrient too and so is the electricity since we both provide nourishment in some form. I know that this is argumentative, but treating all things as "nutrients" is as dangerous as saying that all "coral" are the same.

Anyway, it would be easier for people to understand that light=>zoox=>sugars=>food vs N&P=>tissue creation.

Also, some N and P is needed for not only growth, but also some repair. This is where the host recycling things like N, P and Aminos comes in where this lessens the effect on the coral in periods where new/fresh N&P is not available. Super low levels of N and P are not good and are growth limiting, but they should not lead to death... at least not for a while (nothing lasts forever). Once you understand what N and P do (not energy), then it is easy to see why this is true. This is why it is especially bad when corals expel their zoox during bleaching events in the ocean - they expelled all of those building blocks that they literally spent a lifetime obtaining. Most coral don't ever get them all back again.

It is not likely that low levels of N and P killed somebody coral quickly... it was most likely something else and the N and P got blamed since somebody can test for it. The answer is a lot more complicated, but it takes work to figure this out.

I like the differentiation between the importance of sugars versus nitrogen and phosphorus in coral growth. It is very true that sugars provide the energy needed for these animals. I also like the analogy of the bricks and mortar, I think that helps reefers to understand the differences. I also agree that N/P are certainly not good for the coral and at low residual levels one should not see coral mortality if there are plenty of fish being fed in the tank. I think it will be tough to change the terminology behind nitrogen and phosphorus being nutrients because that is how they are referred to even at an academic level. You make lots of great points and I appreciate the contributions to the discussion. I hope that reefers will read this and begin to consider their feeding habits and what they mean for the health of their reef as a whole.

 

[Brandon McHenry]

I just wanted to show everyone what my “heavy in” looks like for the night after 4 rounds of pellets earlier in the day. I’d love to see what other heavy in heavy out reefers feeding habits look like!

 

[Brandon McHenry]

This guy is one of the reasons I feed so much

 

[Reefahholic]

Coral Food: sugars from the zoox and any carbon in an organism that they can catch. This is energy.

Building Blocks: N and P (and other things). These are not energy. They are used in organic organic tissue.

More sugars from the zoox means more energy and faster growth. More N and P does nothing over "enough" as long as you are not growth limited. Think of sugar as a mason and N and P as bricks and mortar... your masons can only work so fast, but if you get more masons, then you can work faster as long as they are working slow enough that the old layers of laid bricks have cured and can support the new layers (you can only go so fast). The bricks and mortar need to be supplied in small increments all of the time or else they would overrun the place with mess and the mortar would cure before you could use it. You cannot have massive amounts of brick laying around or else nobody could move and work... and you cannot make all of the mortar at once or else it will go bad. Not having any bricks and mortar is bad.

N and P are not energy or food. When people say "feed your corals, dose N and P" they are wrong.

Jda, what is the best food/sugar source (mason) that you feel corals feed on uptake the best?

 

[Reefahholic]

I will just keep my thoughts to what happens in our tanks.

First, plankton and bacteria are not the same. The bacteria can be caught and assimilated in the slime coat with nearly all energy transferred. Plankton needs to be caught and digested by a polyp. Some of this is a math problem of surface area and contact chance.

Bacteria is easy since it appears that the catching and energy transfer is total and efficient.

Plankton is harder since it is unknown that anything that we offer them has enough energy to make the catch and eat worthwhile. It has been always "known and assumed" that phyto is not right for most SPS (at least since I have been reefing since the early 1990s) - this is always subject to change like all science, but there is a lot of evidence that phyto is not right. For zooplankton to work, it needs to probably be live and also the correct size (nobody really knows and each coral seems to be different) and then has to be teeming with nutrition to make the catch and digest worthwhile. Nobody know if any of this is correct.

We met a marine biologist from the Coral Sea that told us that the clean-water acropora reefs in the area did not get nary any supplemental feedings except under extreme circumstances, but the shallower reefs and lagoons more near to the shore would get some. Light delivered nearly all the energy to the acropora in these clear-water areas.

In the end, dosing phyto or live zoo probably does not hurt anything as long as you can export on the back end and N and P residuals do not rise (kinda like Aminos), but I personally do not think that it does what people think that it does for the corals. Some phyto and zoo might really help some pods and stuff, which can be good - so phyto to the whole tank is a different calculus than phyto for acropora. Just like other types of dosing, it is certain that it is not necessary whatsoever since there are just too many long-lived thriving tanks that don't add any.

I think that if everybody just assumed that light was the only energy, then they would be better off. Any benefit from a feeding could just be additional.

What is a good bacteria source to add back to the system.

I agree with you on the phytoplankton. There’s a lot of reefs that made TOTM that were very impressive 15-20 years ago. Zero phytoplankton and they all ran T5’s or Metal Halides. No Reef Roids back then either. ReefBum had a beautiful tank back then. I believe good quality light does wonders for a tank if you can get everything else balanced.

 

[Stigigemla]

I think the corals need their N and P to grow. But in a heavy fed tank they can get it from residuals of the fish feeding so there they can have a good life despite low N and P values in the water. And of coarse the coral animal can use other things than N and P from the fish food residuals.
In my experience the corals grow best with a healthy sized fish community and maybe a little N and/or P added.
The normal values of the tank water is also important. Light, circulation, temperature, alkalinity, Ca, Mg and more.
I recommend my customers 0.03 to 0.1 in phosphate and 1 to 10 in nitrate.
I am not certain if the adding of amino acids do much for corals. I have not seen any difference in coral growth in tanks with a good fish community. But with amino acids added you will often see a better polyp expansion so I think they act more like a signal substance telling the corals that food is in the water.
The skimming is also important. For success with mushrooms and most zoas I think low skimming is best while many Acroporas withstand very powerful skimming good.

 

[jda]

Jda, what is the best food/sugar source (mason) that you feel corals feed on uptake the best?

Lighting is the only reliable source of energy for the corals. Focus on wide spectrum from 350-850nm and multiple angles to hit the coral with as much surface area as possible.

 

[jda]

I did some reading and also talking with a flampton regarding amino acids. The host has the ability to supply their symbionts with all needed amino acids - essential and otherwise. Nobody knows if the host can make their own amino acids, but there has not been any evidence in science or any study that hosts are starved for amino acids - even in a different kind of study, this would have been found in control in most cases like other deficiencies are found. Remember that aminos are building blocks and not food/energy. It looks like hosts can recycle amino acids like they do other building blocks... so they mostly only need new to grow and not just live (at least in the short term).

Here is the crux... just adding a few types of aminos is unlikely to do anything. If the coral was starved of aminos (another building block), then adding a few, but not all would not do anything since the corals would still be growth limited by others. Even if a supplement did have all of the essential aminos, which is very unlikely, then it still does not look like any coral needs them. Nearly no manufacturer tells you what aminos are in their products, but the few that do list only have a subset in the solution... and nobody appears to know if that subset it hard for a coral to obtain than the others.

It looks like aminos are not really doing much/anything for coral, but this is not 100% certain - the claims that a manufacturer makes appear to be unfounded in the larger picture, but you can also argue that this entire post is too. However, they are likely getting used in some way by single cell organsims in the water column and on the surfaces of your tank. Who knows what difference this makes.

 

[Reefahholic]

Lighting is the only reliable source of energy for the corals. Focus on wide spectrum from 350-850nm and multiple angles to hit the coral with as much surface area as possible.

I always run T5’s because I feel it is one of the best light sources out there. I’m my last fixture I ran two 6500’s, but wow it was yellow. So I dropped down to one. Some of these T5’s bulbs have a good range. What are your go to T5 bulbs If you weren’t running MH’s?