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R2R Username: @Roberto Denadai
Build Thread: My new SPS Tank

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Hi guys, I am honored to have my tank featured as “Reef of the Month”! This means a lot to me and I am excited to share my tank and my journey with you all. I was not expecting to receive the Reef of Month nomination because there are lots of beautiful reef systems beyond mine.

First, I want to tell a little bit about myself. My name is Roberto Denadai, I am 48 years old, was born and raised in São Paulo – Brazil, and I have two kids (14 and 9 years old), one dog, two birds, and two planted aquariums.



I graduated in Physics, but I worked 12 years in investment banks as a risk manager and trader. In 2010, I opened a Quantitative Hedge Fund and I managed it for 8 years. After that, I sold the company, and now I just trade and invest my own money. I need to trade well to buy corals. :cool:

When I was a kid I loved birds, and I had more than 200 in my house in a huge aviary. I never thought that in the future I would enjoy the saltwater hobby.

Before I built my first tank, I bought a lot of books to learn with the masters (Sprung, Paletta, Borneman, Nielsen & Fossa, Skimek, etc.). I think that my success with all my tanks has a lot to do with the books that I read and what I learned before the starting line. I've had about 11 tanks in 22 years in this hobby. Each tank was unique and I love them all.

In 2007, I went to Egypt and I dove in the Red Sea. I did a live-abroad for seven days, and this trip was amazing. Seeing corals and fish in the wild is something that I will never forget. You guys can see some pics that I took with an old P100 Sony camera in my blog: In this blog, I also have some pics of my old tanks.

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System Profile:
  • Display tank: 105x60x48cm 302L (41"x24"x19") 80G
  • Glass or Acrylic: Glass 10mm
  • Stand: Custom Build
  • Sump: 15G - My sump has 2 compartments. I have live rocks, seachem matrix, siporax, and some bottles with sand.
  • Protein skimmer: Reef Octopus 1000SSS
  • Carbon/phosphate filtration: Not using it anymore. I just used it in the first months of the tank being set up.
  • Return pump: Nyos 2700
  • Water circulation: Gyre, MP40, and Nero 5
  • Calcium/alkalinity/magnesium dosing equipment: 3x Kamoer X1 dosing and 1x Kamoer X1 PRO
  • Lighting (display): Pacific Sun 8x39w T5 (3x Blue Plus 2x Coral Plus 3x Sylvania 15K)
  • Auto top-off: Gravity float
  • Heating/cooling: Eheim 2x 100W heater / Fan
  • System control: Apex



Water Circulation and Flow Summary and Objectives:

I think flow is the most important thing in a reef tank. You must have strong and random flow to avoid dead spots and avoid a lot of detritus. In this tank, I have 3 kinds of pumps that together generate excellent flow. Being a bare bottom tank is very important because you can adjust the flow looking out for the corals and not looking for holes in the sand bed.


Water Parameters:
  • Temp: 25-27C / 77-80F
  • pH: 8.1-8.5
  • Specific gravity: 35 ppt (1.025)
  • NO3: 0 ppm (Salifert)
  • Ca: 400-420 ppm
  • Alk: 7-8 dKH (Hanna)
  • Mg: 1250 ppm
  • K: Never tested
  • PO4: 0.00 – 0.03 ppm (Hanna ULR)
  • Ammonia and nitrites: 0 ppm
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What salt mix do you use? (Feel free to add why you choose this one.)

Now I'm using Aquaforest Reef, but in this tank I also used Red Sea, Fauna Marin, and two Brazilian brands (Veromar and Mbreda).

What kind of rock did you start with? (live, dry, combination)


What is your substrate?

My tank is bare bottom, but I have some bottles with sand in my sump.

Calcium/Alkalinity/Magnesium Summary and Objectives:

I was never a fan of chasing numbers for calcium and magnesium in my tank. I just test for calcium and magnesium once a year. My main concern is about alkalinity. I test alk once a week, and I try to keep alk around 7-8 dKH.

I started this tank using only kalkwasser. After two months, I also dosed Tropic Marin Balling. Then I changed to carbocalcium plus Barrak Balling. And now I´m with Aquaforest ABC+ and Carbocalcium. As we can see, everything works well.

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What and how do you dose for the big 3 (alk/cal/mag)?

I'm using 3x Kamoer X1 to dose Aquaforest Balling ABC+ and 1x Kamoer X1 PRO to dose carbocalcium.

Are you dosing anything else for your reef health (carbon dosing, aminos, etc.)?

I'm testing the Aquaforest Line, and I'm dosing NP PRO, BIO S, PRO BIOS S, and Amino Mix.

Lighting Photoperiod:

Display tank: T5 from 11:00 AM to 7:00 PM

I started this tank using 3x Hydra 52 + 4x T5, but after 20 months I changed to Pacific Sun 8x39w T5. I'm a big fan of T5 lighting.


Filtration and Water Quality Summary and Objectives:

My skimmer and all my corals keep the water ULNS (Ultra Low Nutrient System). It's very easy to keep NO3 at 0 and PO4 very low in this tank because I have few fish and I don't add too much food.

What is your export strategy?

Currently, I use a skimmer, medias in the sump, and water changes for nutrient export. In the first two years, I did only 10% water changes monthly, but now I'm doing 5/10% water changes weekly. I've never had any issue with NO3 and PO4 in this tank.

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What is your maintenance routine?


  • Fish feeding
  • Quick equipment inspection
  • Glass cleaning
  • Skimmer cleaning
  • Inspect corals/fishes
  • 5-10% water change
  • Check water level for top off.
  • Test alkalinity
  • Clean pumps when they get dirty
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Tank Inhabitants—Fish:
  1. Clarkii Clownfish
  2. Yellow Tang (10 years with me)
  3. Damsel Kupang
  4. Pseudochromis aldabraensis
  5. Bristletooth Striped Tang
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Tank Inhabitants— Corals:

Honestly it's too long to list, so I'll just keep it simple. Also, I don´t know all the SPS names.
  • SPS
  • LPS (Hammer, Frogspawn, Torch, Plate)
  • Zoanthus
  • Leather
  • Trumpet
  • Gonioporas
  • Cloves
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Fish and Coral Feeding:

I feed the fish twice a day with pellets and flakes. I've never fed my corals before because I believe fish poop and fish food is enough in most cases, but now just for fun, I'm using the full Aquaforest line. I'm feeding my corals with phyto mix, rotifers, powder food, amino mix, and AF vitality. I started dosing Aquaforest line in this tank only 3 months ago.

How did you decide what to keep in your tank?

My main focus is SPS. Fish are mainly there to feed the SPS and to give some movement to the tank.

Any stocking regrets?

I wouldn’t say I have stocking regrets. It's more placement of corals. In this tank, I made a mistake of adding too many SPS frags and as they grow they can touch each other too easily.


I'd like to ask you about your thoughts on the recent thread Explain why Roberto can break the SPS rules and succeed? In that thread, the OP seems to think you "break the SPS rules" and found success doing it. Do you agree or disagree with that thought? What do you think might be different in the way you set up a tank from traditional reef hobby methods?

Talking about this thread, I do have some thoughts to share. First of all, I do not think I'm breaking the rules. We all know that there are a lot of ways to keep and build a reef tank. The only rules that we must follow are the water chemistry rules because that is what has science behind it.

Here are some of the questions from that thread's original post: How were you able to keep the acros alive in a new tank? Why don't you get dinos in your tank with low nutrients? Why didn’t your tank get the ugly stage?

About my tanks, I started some tanks with dry rocks, others with live and cured rocks and all of them worked pretty well. Back in 2000 everybody was looking for NO3 and PO4 to be kept very low, and I don't remember any problem with dinos or anything like that. Today, people are afraid of ULNS (Ultra Low Nutrient System) reefing methods.

One question, what is a ULNS tank ?

If your tests are saying you have NO3 is 0 and PO4 is 0, this doesn't necessarily mean to me that this tank is ULNS. For example, you can have tons of corals and feed tons of food daily and all your corals are pretty happy and they are consuming everything in the water, and then you test for NO3 and PO4 and you get a "zero" reading. On the other hand, you can get a reading of zero for NO3 and PO4, and your corals are pale and starving.

The best test you can have is your eyes and your experience and knowledge. You must be very aware of what is going on in your tank. Pay attention to details, and try to understand and learn with your corals. Look at your corals and ask, do they have strong or pale colors? Also, look to the polyps extension; look to the tissue and the pigmentation. How your corals look is the best indicator that you have to determine if your tank is in happy mode or starvation mode. Use tests as a guideline, but always look to your corals.

About ULNS and dinos, I don't have the answer. I never had a problem with dinos, but today people like to run huge skimmers and maybe this could be a problem. I like to run a skimmer that is compatible with my tank size.

Another thing that I did on some of my tanks is that I added corals first and only added fish after one/two months. Remember, fish produce waste, and you have to feed them, while corals uptake nutrients from the water. Adding too many fish first while your tank is new can cause the “ugly stage” because there is no equilibrium yet in the tank and nutrients are floating around, giving algae the opportunity to thrive.


What do you love most about the hobby?

Being a Hedge Fund Manager / Trader is something that requires a lot of mental energy and sometimes can be very stressful. Keeping a reef at my house is a way to relax and have piece of mind. Besides that I like the journey. Starting a reef with frags and seeing them grow and thrive is really nice. Also, I've made a lot of friends in this hobby. I love to talk and share experiences with friends. One of them is Paulinho (@Reef and Dive). Paulinho is an amazing guy that shares his passion and knowledge with the community and we learn a lot from him.


How long have you been doing this?

22 years (I´m getting old.)

Who was responsible for getting you into the hobby?

When I was young I was walking at the mall, and I saw a big tank with a lot of saltwater fish. I just loved the shapes and colors. After that, I made my first trip to the USA, and I went to a lot of public aquariums and Sea World. When I came back to Brazil, I bought my first marine tank. My first tank was very simple, T8 bulbs, just kalkwasser and water changes. You can see my first tank here:

Who or what in the hobby most influences/inspires you?

Keith Berkelhamer (@ReefBum) is my hero in this hobby. When I saw his tank for the first time in july 2003 as TOTM, I knew that I wanted something similar. In march 2009, Keith was TOTM again and that tank is a masterpiece in my opinion. I designed my first SPS tank trying to reach Keith's level, and I think I was pretty close. This SPS tank in my opinion was the best tank that I had. You can see this tank here:


If you could have any tank, what size would it be and why?

Maybe a 1000G tank. I love tangs, and a big tank would be very nice.

Favorite fish?

Powder Blue and Sohal tangs

Favorite coral?

Torches and SPS in general


How do you typically get over setbacks?

In 22 years, I had just one big setback in my SPS tank. In 2005 my tank got AEFW. AEFW was something new to me, and I lost a lot of acros. But I think that you win or you learn. Use failures to learn and get ready to reach the next level.

Have you faced any major challenges with this particular tank, and if so, how did you overcome?

In this tank, the only problem that I had was bubble algae (valonia), but I fixed it by dosing Vibrant.

What's the best thing you ever bought for your tank?

Maybe the Pacific Sun T5 fixture.

What are your future plans for improvement/upgrade of the tank?

I´m going to move to a new house, and I still don't know what I´m going to do with this tank.

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Any special tips for success or advice you'd like to share with other reefers?

Never expect to have a perfect reef tank because no one has a "perfect tank" in a short period of time. Also, try to learn as much as you can about fish and coral species so you don't regret adding a coral or fish later. Reefing is very easy; you just need to know the fundamentals and be patient. Dedication is essential if you want a beautiful tank that will thrive in the long run. Read good books and only take advice from successful people.

Final Thoughts?

Feel free to message me anytime on my instagram roberto_denadai or in my YouTube channel.

Life is too short, enjoy every day. Be kind and learn as much as you can. Knowledge is something that no one can take away from you.