the secret to colorful,healthy corals....obvious to some,elusive to many

[kevensquint]

Well for the past year I have been researching online to try and figure it out, at first I thought it was mostly lighting dependant, and I blamed my Radion for my pale corals. I have crossed-referenced years of beautiful TOTM tanks as well as info from coral health companies, articles and my own observations.

Today, I believe there is a very real link between light intensity and Alkalinity level. I also believe there is a 3rd important factor involved nutrients PO4 and NO3.
According to almost all of the data, it seems that strong light, along with low-medium Alk levels ensure good coral color/health. It also appears that in many cases tanks with slightly higher levels of Alk get away with it by have nutrients higher than 0 ppm (PO4/NO3). Its as if the nutrients ensure the zooxanthellae have at least the fuel to keep their populations reasonable, which then keeps the corals from becoming pale in a harsh high Alk environment.
This is my hypothesis and here are the reason's why:

In my own tank, my Alk over the past year was at 9-10 DKH (high),my PO4/NO3 was 0.00ppm/0 ppm always. My corals would become pale, growth was good, but not color. at one point, I removed my GFO and fed the tank more, after a few weeks, algae started to grow, my PO4 and NO3 had risin to 0.08ppm and 1 ppm, I was able to increase my LED intensity to the highest level I ever had, coral growth exploded and colors intensified. Due to the increased algae, I became concerned, replaced the GFO and increased water changes. PO4/NO3 dropped to 0 again, algae dissapeared and so did my corals colors.

Here are the Alkalinity parameters suggested by KZ /Fauna Marin and Aquaforest to ensure best coral growth/color. These companies mention that strong, adequate lighting and very low PO4/NO3 is also required.

KZ 6.5-8 DKH
FM 6.5-8 DKH
Aquaforest 6.5-7.5 DKH (color) and 7.5-9 DKH (growth)

so we can assume 7.5 DKH overall.

The ocean: 7.2 DKH and the lighting is ofcourse the very intense sun and nutrients are very low.
Here is the data from 18 amazing colorful TOTM tanks, I basically went straight down the list from 2012 and 2011 in a U.K based forum.

(Light): (Alk): (PO4/NO3) levels:

(T5) (7 DKH) (0.00 ppm/0 ppm)
(250w MH+Led) (9 DKH) (0.08 ppm/48 ppm)
(250w MH/Led) (8.6 DKH) (0.08 ppm/2 ppm)
(T5) (8 DKH) (0.01 ppm/5 ppm)
(400w MH) (8 DKH) (0.01 ppm/0 ppm)
(250w MH/T5) (7.8 DKH) (0.01 ppm/ 4 ppm)
(T5) (8.5 DKH) (0.08 ppm/0 ppm)
(400wMH+T5+Led) (7-7.5 DKH) (0.00 ppm/0.75 ppm)
(T5 (6 hres max.)) (8-10 DKH) (0.02 ppm/0 ppm)
(VHO) (9.6 DKH) (0.00 ppm/0 ppm)
(T5) (9.0 DKH) (0.03 ppm/10 ppm)
(VHO) (11 DKH) (believed to be 0 ppm (not often tested))
(250w MH) (8.4 DKH) (0.02 ppm/0 ppm)
(T5) (7 DKH) (0.00 ppm/0 ppm)
(T5) (9.5 DKH) (0.05 ppm/3 ppm)
(250w MH) (8 DKH) (0.01 ppm/0 ppm)
(250w MH) (8-9 DKH) (0.00ppm/10-15 ppm)
(150w MH) (7.8 DKH) (0.00ppm/2 ppm)

So what does all this mean: Well aside from the many contributing factors such as food, other parameters, additives etc...I wanted to see if there was a common link between amazing tanks.
There appears to be: in a nutshell, assuming you use intense lighting, you can usually get away with a higher Alk level if you also have PO4 and/or NO3.
If you have very low nutrients, then it will usually give you best results with a natural Alk level 7-8 DKH. Nothing is 100% true, but from what I have found, I will bet on this idea more than any magic bottle in producing good results.

 

[ReeferBatman]

When studying intently into light and corals (many peer reviewed articles... google scholar is your friend ) I came across a great read...

Can't find the link now,

But they found out that the largest factor to actual light getting to the corals in a real environment [deeper than our tanks] is the amount of dissolved solids in the water.

Think of it like this... the more 'stuff' is in the water, the more light is blocked/scattered.

Coincides with your observations.

It seems like your lighting was too intense for the corals, and you balanced the equation by letting more 'stuff' congregate in the water to then lessen the intensity of the light that the coral's actually received.

 

[kevensquint]

I hope some people confused of why their corals are pale, will take a look and see if my suggestion will help. I also want to know why salt companys sell salt with such high Alk levels. I have seen a few salt mixes above 12 DKH for goodness sake.

 

[scolley]

Thank you for sharing! Wonderful research. :thumbsup:

Before I ever put a drop of water in my first reef tank I did similar research. But I was not selecting for colorful. My results were different because I was selecting for long term success. But even those were generally lower Alk levels than are typical here on RC. As such my dKH is 8 - or a shade over - and never more. And my NO3 is typically undetectable, and PO4 from 0.5 to 0.2. And my LEDs are bright.

And guess what? My SPS are nice and colorful. So IMO... You are onto something. Thank you for sharing this, and look forward to the community response.

One question though... Did you check your premise against RC TOTMs? Would be curious to see if it held up as consistently here.

 

[kevensquint]

Thanks for appreciating my time spent. I tried to find a pool of beautifully colorful tanks that included parameters.I think in RC, params are often mentioned, but not everytime.
I'm not sure if I'm allowed to mention another forums name, but the largest reef firum in the UK has a TOTM archive that shows a complete list if each tank's params from 2012 back to about 2001 if I remember correctly.

 

[kevensquint]

If I may take it one step further. Notice how the companies selling coral color products are specific about intense/ proper spectrum lighting, NSW alk levels and low nutrients. So its not far fetched to imagine that under those conditions as long as the tank is not poisoned by the additives, with or without them good colors would have come either way. Food for thought

 

[DHyslop]

I also want to know why salt companys sell salt with such high Alk levels. I have seen a few salt mixes above 12 DKH for goodness sake.

90% of the people who buy salt mixes are the "unwashed masses" in the hobby who aren't routinely testing and dosing regularly to maintain target values. They have a hammer coral in with their xenia and toadstool leather, and if they weren't doing a water change once a month with 12 dkh water it would die.

Same reason Oceanic salt mixes to like 500 mg/l calcium.

 

[kevensquint]

Oh!...thats too bad. I was sure 90% that follow that husbandry was way back when I started 20 some years ago. Judging from how many speak of dosing 2-part and using Ca reactors, I had thought the opposite.

 

[scolley]

They have a hammer coral in with their xenia and toadstool leather, and if they weren't doing a water change once a month with 12 dkh water it would die.

Well, if true, that would certainly explain why so many Reef salt mixes have many levels way above NSW. Alk included.

Judging from how many speak of dosing 2-part and using Ca reactors, I had thought the opposite.

I've only been reefing a few years. But I'm constantly surprised at the number of reefers that I meet that tell me,

"Yeah. I change X gallons every Y weeks and I'm good to go. I don't have time for dosing and testing. Works great!"
​

Though I cannot recall any of them keeping colorful SPS either.

 

[Nano sapiens]

Kudos for coming up with the tank stats.

I hooked onto this concept a couple weeks ago when I was researching any ORA Red Planet Acro issues that people had run into. I was trying to find common denominators so that I could get a handle on my bleaching/pigmentless specimen. Some folks had color improvement when they lowered their alkalinity from ~10 to near NSW levels. This lead me to the ULNS forums and threads where lower alkalinity is the standard due to non measurable NO3 & PO4.

In my own tank, which has consistent '0' NO3 and PO4 (Salifert) and moderate LED lighting, I have been slowly decreasing alkalinity from ~10.5 and am now at 8.8 dKh, with the ultimate goal of 8.2 dKh. Results are still early, but changes/improvements in some of the SPS have already been noted.

I have found that the interrelationship between alkalinity, lighting and nutrients is more complex and important than previously recognized.

 

[Ron Reefman]

Oh!...thats too bad. I was sure 90% that follow that husbandry was way back when I started 20 some years ago. Judging from how many speak of dosing 2-part and using Ca reactors, I had thought the opposite.

Keven, as a member of a local marine reef club, I can't give away corals like green star polyps, waving hand or kenya tree coral on our club website (150 members). I'm not sure they would take it if I offered to pay them. But I put it up on Craigslist at $10 a frag and they sells like hotcakes! And I'm only able to rope in about 10-20% of the CL customers to the club, the rest just don't get it or don't care.

I don't think it's 90%, I think it's closer to a 50/50 split. But the 50% who never learn how to keep a tank leave the hobby regularly and new uneducated hobbists join the hobby. That's how LFS stay in business. It's also why there are so many good deals for beginer equipment on Craigslist.

 

[Big E]

On alk---

Back in '98 Dana Riddle was linking high alk with stronger colors. I'm not sure if he ever did any follow up. Going from 7 to 10 he would see improvements in a few days in color intensity. He was working to see if there was a link to alk and zoo density levels. RC won't allow a direct link, so pm me if interested in this.

Back then, everyone was into 400w halides & high intensity lights also, so there might be a link to all that.

My tank looks best between 8.5-9.5.

On the nutrients---

I prefer higher nutrient levels + intense lighting as being the best combination for coloring of acros. I hate the pastel look and want darker vivid colors.

I've had my best results for growth & color at PO4 ranging from .08-12ppm and even higher in the teens has been fine. Near or above .20 the algae is too hard to control.

I don't chase numbers and go by watching the acros & algae, so to me it's more about finding a balance by observation, and using the numbers as a range to be in.

It's important to have the food/nutrients flowing through the system.......... the end test read out has little value than to make sure I'm inside a range.

The best example I can give is that if two 100g tanks read .03 the tank with 8 fish to feed will have better colors than the same .03 tank with 2 fish.

I don't test nitrates on any regular basis, but I always get 0 on salifert.

Here's an interesting link concerning PO4---

http://www.sciencedirect.com/science/article/pii/S0022098111004588

What I find interesting is that they used .09 as the very low range.

On lighting--

Once in a balanced range that's when it's imprortant to have the correct spectrum and intensity in lighting.
This link is kind of a summary to some of Dana's earlier articles---

http://www.advancedaquarist.com/2009/1/aafeature1

If you want to get into further depth read these also--

http://www.advancedaquarist.com/2009/1/aafeature1
http://www.advancedaquarist.com/2006/11/aafeature2
http://www.advancedaquarist.com/2009/4/aafeature1
http://www.advancedaquarist.com/2007/2/aafeature
http://www.advancedaquarist.com/2007/6/aafeature2
http://www.advancedaquarist.com/2007/7/aafeature1

 

[Big E]

dbl post

 

[Spyderturbo007]

Great thread and just what I'm struggling with right now. My tank is ULN with Nitrate at 0pp and Phosphate at 0ppm. My Alkalinity was at ~10dkh and the few corals I had bleached out over the course of a few days.

I've dropped my photo period and reduced my Alkalinity to around 8.3dkh and I'm starting to regain color again.

My current issue is that following a water change with Instant Ocean, I get an Alkalinity spike because IO is so high in Alkalinity. I just noticed it Friday during my bi-weekly water change. Alk spiked from 8.3dkh to 8.9dkh just because of the water change.

I'm wondering if I should change salt mixes, or add HCl to the mix to drop the alkalinity?

The problem is that I just bought a bunch of salt right before I thought this might be the correlation.

 

[sirreal63]

Good job on data gathering, one thing sticks out in my mind though, how was the po4 and no3 tested? If everyone used the exact same tester then results would be more consistent, however if one person used API, another Salifert, another Red Sea or any of the numerous tests available, then the actual readings would be significantly different from one tank to another. Saying it is zero or any number lacks accuracy when a myriad of testing methods are used.

Your experience with nutrient levels mirrors my own over the years. I get better color when nutrients are higher but also an increase in algae on the glass and cyano pops up. I am dealing with it, because I want, and the corals need, the nutrients after a bleaching from an increase in light levels. I think most people rely too much on trying to replicate the nutrient levels of the reef in their tanks, our tanks do not function the way a reef does, a reef has massive amounts of food available and very low nutrients in the water. If we strip the nutrients and do not have a corresponding plethora of available food, then the corals suffer.

All of this coincides with Big E's findings as well. Sometimes we get too fixated on a number and ignore what is happening in the tank. The corals are the best indicator of proper nutrient levels for a tank, his levels may be a different number than mine, but each of our tanks has different nutrient processing abilities. There is no general correct number for any tank, but rather a number that is best for each tank, and they will not all be the same.

 

[d2mini]

Thanks for appreciating my time spent. I tried to find a pool of beautifully colorful tanks that included parameters.I think in RC, params are often mentioned, but not everytime.
I'm not sure if I'm allowed to mention another forums name, but the largest reef firum in the UK has a TOTM archive that shows a complete list if each tank's params from 2012 back to about 2001 if I remember correctly.

You can also check out sites like Aquaticlog.com
People like myself that have really completed their profile have all the parameters you can view along with pics and video of our tanks. My tank is too new to be of any help but maybe there are some others on their that can help you.

 

[scolley]

From the data presented this looks like a "low or no phosphates" conclusion regarding low dKH and colorful corals. However, without knowing the mechanism the various reef keepers reporting zero phosphates used to test, we don't know the water really had zero phosphates.

Some test kits give no reading beyond a certain low number, leading the tester to conclude zero. Salifert is an example of this. Such kits could lead one to believe you have zero phosphates when - in fact - you are running at 0.02, 0.01 or even 0.005. Those are all low, but decidedly non-zero.

Bottom line, without knowing the testing mechanism for phosphates on the tanks reporting zero, the only conclusion that we can draw is that they had very low phosphate tanks. Taking the zero-phosphate reports at face value requires more information (testing mechanism) to be wholly trusted IMO.

 

[Cstaricansrfer1]

Very interesting read for me. It seems like I have read so much about the relationship between Alk, Ca, and Mg but never really about P04 producing a direct correlation when increasing it with regard to Alkalinity. Thanks for sharing.

I might have to do some experimenting with this and see what results come.

 

[scolley]

The ocean: 7.2 DKH and the lighting is ofcourse the very intense sun and nutrients are very low.

Is it true that nutrients are very low on/around reefs? I know that NO3 and PO4 are, but what about those things in the water that are used as particulate food by corals? When food breaks down I assume it BECOMES NO3, PO4, and many other constituent compounds. But is it fair to say that nutrients are very low on reefs?

I ask because it has been my impression that there are number of very successful reefers out there - with very colorful corals - that keep their NO3 and PO4 readings low, but through the feeding of their well-stocked tanks, are putting abundant nutrients into the tank regularly. But with aggressive skimming and other water filtration methods, they manage to maintain tanks that are overall low in NO3 and PO4. But the food available for their corals is abundant.

 

[Reeferz412]

I used to perform a water change on my mixed reef every week, now I do it every 2-3 weeks just to see what would happen. Algae is beginning to grow slowly, but my zoa's, lps, and softies are goin nuts! You win and lose here because I got little pieces of algae to pick at every couple of weeks.