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July 2013 Tank of the Month



Hello everybody! My name is Jean Yves and I am 37 years old. I live in Toulouse, in the south of France, not so far from the sea. I find that our hobby has an ambivalent attitude, and for me I consider it an illness and a medicine.

My approach is mainly artistic and since I am in love with nature, I have found this hobby enjoyable. I am the kind of guy who can sit and observe a bee on a sunflower for hours. By profession I am a musician with a focus on jazz music; I play bass and studding trumpet.

English is not my mother's language and writing this article is ambitious, to say the least. I am a musician not chemist, but I will discuss how I maintain my calcium, dkH, and pH in my aquarium.


This tank was setup and filled in April 2010. This makes the aquarium just over 3 years old. The aquarium holds 520 liters (~130 US gallons) and is lit by 54W T5 lamps (x10). The dimensions of the tank were chosen following the ‘golden ratio’ and are 130cm x 80cm x 50cm. I have found the golden ratio is ideal for aesthetics when selecting an aquarium. The aquarium is made from acrylic and has an external overflow made by Shuran.

In October, the two Vortech Mp40s were becoming insufficient because of the coral growth. I had to add a Tunze 6095 and decided it was time to rebuild a part of the aquascape. This decision was difficult to make, but I thought ‘tomorrow was another day’! Thinking about the future, I figured this tank would be nice again in a few months. It took some time placing the rockwork to be displayed in an asymmetric way, trying to recreate the natural look of a reef, without making it seem like I was trying to make it do so was incredibly difficult. Along with fixing corals in a manner to allow subsequent growth, while allowing me to clean the acrylic was the hardest part in this hobby! The concept of this aquarium was to have nothing on the top of it, nothing under it, nothing in it visible, but life.


The light fixture is a Blau-Aquaristic Lumina 1054 [54W T5s (x 10)]. I retrofitted the fixture by removing two T5 bulbs and placing nine 10 watt LEDs within this space. The current composition of the lighting in the fixture is:

Pink T5 x2

Blue T5 x6

10W LED 10000K x6

10W LED 15000K x3

Sump and Equipment

The sump is in the basement and I have to say having the sump in a well-ventilated place is a key part of success. Possibly just having the air injection from the skimmer should come from outside would be beneficial. My problem is when we play music, as many as seven people could be in the basement, and I worry about the amount of carbon dioxide produced. Due to this carbon dioxide production, I prefer to cut the amount of calcium hydroxide added to attempt to compensate. The lacking of a well-ventilated room to the outside could potentially have devastating effects on our little ecosystems.

An Aquatronica controls everything and the sump pump is an Iwaki. The skimmer is a capricious ATI 200i. The sump had a deep sandbed (DSB) consisting of 50 kilograms (110 pounds) until November 2012. At that time the DSB was replaced by a bacterial reactor. I do not have enough experience yet to talk about it. While I did this, I also rebuilt a part of the display and added a Tunze 6095. I had some necrosis on my corals as a result; maybe I should have done nothing!


I’m not a chemist and neither a biologist. Taxonomy of corals is a very difficult job, and I have to say it is seemingly useless to me, so I rather just appreciate their beauty.

I am almost able to name everything in my aquarium, but what for? Instead let me explain my way of thinking about maintenance, or should I say life support. I feel like a simple gardener, or grandmother caring for her flower. Well, something like this, definitely not a botanist, my skill is only knowledge of observation and experience. You have only got to look of what modern agriculture is, to realize how science can get you away from the basics. The main thing is: trying to not act, being humble facing creation and let nature do is job. Something like reef permaculture.

So my beliefs for my aquarium are: simplicity to mirror the complexity of life, think small and feeding the basics, being highly suspect of miracle powders and sometimes even test results, and being cautious of everything I put in the tank, including my own hands.

Sometimes I use amino acid additives. Rarely I do water changes, but when I do I end up doing a large proportion of my water. Usually, it seems like I do it three times a year and a third of the total volume at a time. I use pure reverse osmosis water, that an important thing to me and strive for zero TDS. Mainly the only things I add in my tank are food and calcium hydroxide.

Water Parameters

That's the big part of maintaining a successful reef! And I am gone try to make it as short and clear as possible: In my tank calcium, dKH are always kept stable and pH is maintained above a value that I define. I use a kalk reactor controlled by a pH meter, but not set to auto-top off. This way it will maintain pH of the water above a defined value with a small hysteresis and also maintain calcium. When the pH of the aquarium water goes under a value that I have defined, a peristaltic pump is activated. This infuses drop by drop a concentrated mixture of calcium hydroxide (milk-like consistency) through the reaction chamber where all the water of the tank arrives.

Then using a second container I allow unlimited refill of evaporated water that has been pH adjusted with calcium hydroxide. A second pH probe and a level probe in the sump directly on the peristaltic pump secure the system.

I calibrate the probe three times a year and I refill the reactor every week. For the past three years my calcium is around 440ppm, dKH is around 7 and the pH is stable at 8.3.


Having a reef tank is definitely not a good idea, but if you do it, do it the best as you can.