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Tank of the Month

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Krzysztof Tryc's (lunar) Reef Aquarium


Introduction & Background

Tank of  the Month – the greatest news for me - ever! Let me thank both the Reef Central staff and all the members of the Reef Central forum who contributed to that, as well as everyone spending time reading this article now. A special thanks to the editorial staff at Reefkeeping Magazine for their great job and placing me among all the outstanding winners of Tank of the Month.

It is very important for me to receive the title of ?Tank of the Month, because Reef Central is the forum that has accompanied me since the very beginning. It is said that if a man can learn from his mistakes, then experience is his best teacher. I believe that this is true. Reef Central has given us the opportunity to learn from each other’s experience and that is really valuable. In spite of many ethnic, ideological and religious differences, we all constitute a large group – a reefkeepers’ community – which helps in hard times, and makes us enjoy the bright moments more.

My name is Krzysztof Tryc (aka lunar). I live in Warsaw, the capital of Poland. Reefkeeping has been my greatest passion since 1996. My first set-up was a mixed tank with soft corals, LPS and SPS corals. I soon got rid of the soft corals; the diversity of shapes and colors of SPS corals enchanted me.

I have tried many different methods, first as a Berlin system, then, for a year, a skimmerless system using a refuge with Miracle Mud and macroalgae, and eventually Zeovit. However, that whole time I have been looking for a method that would be perfect for me. I finally found it – since the 26th of February 2010 I have been using a reactor with NP reducing BioPellets. I do not know whether one can invent anything that could be not only easy but also as effective as they are. The polymers do well, allowing me to keep NO3 and PO4 levels low, while at the same time, efficiently feeding my animals. This method practically means no work on my side. The corals are healthy and grow rapidly, and I’m happy with that.


The Current System

My current tank is built of a 12 mm thick glass; the total volume of the system is about 198 US gallons (750 liters), The tank was upgraded in 2006 from a three-year old, smaller tank, because of my moving to a new house. The frontal and side panes are made of Optiwhite glass. The bottom used to be covered with about 11 cm of live sand initially, but some time ago I started to remove the deep sand bed gradually. Currently, I intend to leave only a decorative layer of sand.




System Profile

• Display tank: (approximately) 750 liters (198 US gallons); 160 x 80 x 55
• Sump:
286 liters (~75,6 gallons); 110 x 50 x 52
• System filtration:
reactor with NP reducing BioPellets and Korallenzucht Revolution M
• Chiller:
Teco 15
• Controllers: pH and temperature
• Ca/KH addition: two-part calcium and alkalinity addition system; liquid additives via Grotech Tec III
• Auto top-off:
Aqua Medic Niveaumat
• Lighting: ATI powermodule consisting of ten 80-watt T5's
• Photoperiod:
2 bulbs on 12 hours a day and 8 bulbs on 7 hours a day
• Water circulation: two Tunze Turbelle Stream 6105, two Iwaki MD 55, Red Dragon 8000 l/h as a main pump


Filtration & Water Circulation

All the time I have been trying to find a simple and almost self-serving system. The one that I have established recently satisfies me. In the main tank there is about 80 kg of live rocks, the other part of the filtration system being the skimmer and the reactor with NP reducing BioPellets in the sump. There is also a Korallenzucht Magnetic Zeovit Reactor S, which I had used for the Zeovit method, but after some adaptation, I started to use as a reactor for the polymers. The water flow through the biopellets is adjusted to about 1200 l/h. As an element of chemical filtration I also placed a bag with activated carbon, which is exchanged monthly. Sometimes filter floss is used as well. That is what my filtration system is all about. As for NP reducing BioPellets, which are relatively new, I am nicely surprised that they work the way as it was promised by their inventor. Might it be a breakthrough in reefkeeping?


Water circulation is provided by two Tunze Turbelle Stream 6105 and two Iwaki MD 55 on a closed-loop system. The Red Dragon 8000 l/h works as a main pump. A Durso standpipe was fitted inside an overflow box to reduce water noise.



The tank is lit with an ATI Powermodule housing ten 80-watt T5 bulbs, and consists of the following dimensions: 1473 x 558 x 60 (length x width x height). The Powermodule has an active cooling system that provides high performance cooling for the electronic digital ballasts (EVG) and the T5 tubes. It is a dimmable ballast, connected to the Profilux II. Like most reefkeepers, I still change combinations of tubes to achieve the most optimal effects.

  • 9:00AM-9:00PM: 2 tubes (they start illuminating at 9 AM and it takes a half an hour to achieve their full power; they start fading at 8:30 PM until 9 PM)
  • 10:00AM-6:00PM: 8 tubes (it takes one hour for them to illuminate and fade)


Maintenance, Feeding & Supplements

To maintain calcium and alkalinity levels I formerly used a calcium reactor. One night I woke up due to some deafening noise. It was like the sound of glass being smashed into tiny pieces. The aquarium crashed – it was my first thought. With a heart beating fast, I jumped to my feet to see what had really happened. It turned out that the valve on the CO2 cylinder had failed. Fortunately, it was only the door of the cabinet where the CO2 cylinder was stored that was damaged – it was torn from its hinges. I felt both relief and anger; I made an irrevocable decision at that moment – no calcium reactor ever again. For several years I have used the two-part calcium and alkalinity additive system. The solutions are added via a Grotech Tec III dosing pump, which is used for supplementing Tropic Marin trace elements as well. Basically, I check the Ca and kH levels every second week and adjust them if it is necessary.


All water changes and top-off are done using RO/DI water. I typically perform about 10% water changes every week. I have tried a lot of brands of sea salt mix over the years and now my choice is Instant Ocean - back to what I used at the beginning.

If not for the necessity of frequently trimming corals, the system would need little maintenance, which usually means emptying the skimmer cup, cleaning the tank's viewing panels, water changing, preparing Ca and kH solutions and replacing carbon. From time to time I check the most important parameters with Salifert tests (Ca, Mg, kH) and with Hanna instruments (NO3, PO4, salinity). Moreover, on a daily basis I monitor the temperature and pH and feed my animals. I use different frozen foods, Cyclop-Eeze, spirulina, nori and ReefPearls.

Water Parameters:
  • Specific gravity: 35 ppt
  • pH: 7.7 - 8.1
  • Calcium: 430 ppm
  • Alkalinity: 8 dKH
  • Magnesium: 1380 ppm 
  • Temperature: 25 - 26 ° C (26 - 28 ° C in the summer)
  • Nitrate: undetectable
  • Phosphate: 0.01 ppm






Years ago I used to have a pair of Pterapogon kauderni, which reproduced quite frequently. The male’s attractiveness was apparently highly estimated by his female mate. How exciting those days were! When the time came where they were producing fry, I had to keep a close eye on the female because – like me - she was waiting for that moment, surely driven by other reasons. She stood opposite her mate upstream, and the released fry flowed directly into her open mouth. She devoured them. I tried to catch as many as possible to transfer them into a small tank connected to the main one. The male should have been separated after the spawning event, but I did not manage to do that. He was too smart and too fast to be caught. Furthermore, the density of corals made my catching him impossible. Breeding Pterapogon kauderni lasted about two years. Then it became too troublesome for me, so I gave the pair of fish to a friend.

Fish & Invertebrates:
  • Zebrasoma xanthurum
  • Zebrasoma veliferum
  • Ctenochaetus hawaiiensis
  • Pomacanthus imperator
  • Halichoeres chrysus
  • Centropyge loriculus
  • a school of Chromis viridis
  • Pseudochromis friedmanni
  • a school of Pseudanthias squamipinnis
  • 2 Amphiprion ocellaris
  • Ctenochaetus tominiensis
  • Liopropoma carmabi
  • Cleaner shrimps
  • Turbo, Strombus, and Astrea snails
  • Brittle stars











  • Acropora
  • Seriatopora
  • Pocillopora
  • Montipora
  • Pavona
  • Scolymia
  • Lobophyllia
  • Ricordea Florida
  • Sinularia
  • Zoanthids


















A Handful of Final Thoughts

When possible, each day I devote a little time to observing what is going on in the tank, so I immediately notice any changes. That is why correcting anything takes far less time, as I do not trust tests fully. When I get a reading different from expected, I do not take any drastic steps. I test again, and in case of further doubts, I take another test or use a more precise meter.

In my opinion, an undernourished coral, just like a human-being, is weak and exposed to numerous diseases. It lacks energy to cope with any mistakes on our part. I believe that regular water changes are very important - if not the most significant thing for your aquarium to thrive. They help to maintain the balance in the tank and ensure its greater stability.

Whenever I go away, I always have somebody keep a watchful eye on it because of this; I do not have to feel anxious, even if the equipment failed. However, there are still things that can happen. One day, on coming back home I spotted my coral, once large, nearly half-shaped. The person taking care of the tank assumed that the coral was bleaching and decided to save it, whereas, in fact, the white tips of the coral were only the indication of its growth. It was an Acropora hyacinthus (in the center of the tank).Throughout all those years I have realized that a method does not matter that much - you can have similar effects with the use of various means - but a man, his involvement and patience are more important. Furthermore, being perceptive and having a bit of intuition are also useful.



Last, but not least, I would like to express thanks to a special person – my wife, Irene. If it were not for her engagement and care, this hobby wouldn’t give me so much joy. Everything seems to be more beautiful if you have someone you can always share your passion and emotions with.



Feel free to comment or ask questions about my tank in the Tank of the Month thread on Reef Central.

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