My Own Aquaria: Part 2 of 3 (The Small Tank)

Posted by on Aug 3, 2011 in All Categories, My Aquaria | 0 comments

My Own Aquaria: Part 2 of 3 (The Small Tank)

Aquarium 2

After I showed off my first, and oldest tank last week, I will share some more pictures and technical details of my second tank with you this week. Building this cabinet involved a lot of experimentation during the design phase. Big thanks go out to Tischlerei Beckmann, who went through this with me in meticulous detail.

Here’s a total view of it:

Total View

Total View

And here’s a front view with my first go at aquascaping. Being an old school Dutch styler, I had a difficult time of it and the rockwork is a bit clumsy but again, I learned a lot from this.

After The Thunderstorm

"After The Thunderstorm"(Ranked 53rd in Aquatic Scapers Europe Contest)

One of my favourite plants: Hygrophila spec. “Crinkled”. I’ll have to get it identified properly one day. If anyone can help me with its identification, that would be great!

Hygrophila spec. "Crinkled"2

Hygrophila spec. "Crinkled"

Another close-up of Urticularia and Staurogyne growing in the foreground.

Utricularia graminifolia, Staurogyne repens

Utricularia graminifolia, Staurogyne repens

It has to be said, this tank is better suited to being run as a classical Dutch aquarium because it is closed off completely with just the front being visible. I like more open tanks for the NA style. That is one of the reasons why I have reverted it back to Dutch.

Anyway, let’s get to the technical details:


Size: 130 x 55 x 55 cm.
Water: 90% reverse osmosis, 10% tap water.
Temp: 25,5°C with a 1° reduction during the night. Still in the testing phase but this is supposed to stimulate plant growth.
Fertilizer: Currently trying different brands with mixed success but that’s going to change soon as I will start trying out Estimative Index fertilizing. Watch this space for results…
CO2: 30mg/l
Light: I run this with a reduction during the day. Lighting intensity is reduced to 7% for 3 hours by a GHL ProfiLux II Computer. I’m hoping to halt oxydation a little with the break. Allegedly, nutrients are kept available longer in a reducing environment. I’m still testing to see if this has a beneficial effect on plant growth. There’s more on lighting below. Here’s the lighting curve for this tank:

Lighting Scheme

Lighting Regime


If you’ve read the post on my other aquarium, you know why I like open filters. Same principle here – the filter is on the same level as the aquarium. It makes for easy access and maintenance. I simply refined the two-column-design further with the whole side opening. Obviously, this cannot be used in a corner space…

This is the left side, opened up:

Open filter

Open Filter

The challenge with this construction was to accommodate the cabinet side which I needed to hold the lid (you’ll see why, further down). So, I had to get an extra long flange to connect the tank and the filter, with the cabinet side sandwiched in-between. My aquarium maker warned me about this because he feared that a settling filter would soon create leaks around the rim of the flange. So far, nothing has happened bit I did have to apply a generous dose of silicone to get it water-tight in the first place.

Filter Section

Filter Section

The pump is underneath the filter to allow maximum space for filtration media. It is also easier to get to in case the pump needs cleaning. The CO2-bottle is also on this side. The first two filter compartments are filled with siporax ceramic material and the first chamber also hosts the probes for temperature and pH, as well as a drop checker. The second and third chambers are filled with blue sponge and the last chamber with filter wool. I know it is time for cleaning when the water level in the last compartment starts to get low. That’s approximately every 6 months. The filtered water is piped underneath the tank and fed in at the opposite side after it has passed the CO2-diffuser, UV lamp, chiller and heater.


The cabinet is mdf with bamboo veneer combined with white finishing for the sides. The plinth has a glass veneer with a coat of white applied to the back. the chiller and GHL computer sit behind the door. The four drawers are used for storing equipment. They have push-to-open latches which makes for a clean and unobtrusive front but is something I would not do again. When I stand closely in front of the tank (like, when I’m trimming plants), I keep opening drawers by pressing them inadvertently with my knees. The drawers themselves are much better than doors though because you can store stuff so much more comfortably, especially if you have lots of small items to stow, like forceps, testing drops and miscellaneous other paraphernalia.

Below is the right side, opened up. Click the image to see more details. I’ll get to the functions further down.

Right Side - Water Treatment

Right Side - Water Treatment


When I designed this cabinet 3 years ago, LEDs were virtually unavailable and ridiculously priced. They are still expensive now but a viable option, especially if your DIY skills are well-developed. So, I had a choice between metal halide lamps and T5 tubes. Hanging lamps were not an option as I wanted this tank to be fully closed – like a classic Dutch style tank. As a result, I was left with T5s.

I had already tried the mirror reflectors on the large aquarium and except for their weight, I found them to have no disadvantages whatsoever. So, I decided to go for mirrors again. Still, the lid design has some small but important modifications, as compared with the first one:

  • For the cover, we used perspex to save on weight.
  • We didn’t fix the perspex sheet to the frame permanently. It runs in a groove so it slides out easily for maintenance.
  • There is now an extractor fan in the centre of the lid. It is very efficient in reducing heat inside the lid which ultimately helps cooling the tank.
Aquarium Lid Section

Aquarium Lid Section

  • The new cabinet design didn’t allow for springs to help lift the lid. We tried run-of-the-mill fittings for kitchen doors but those were no use at all. The master cabinet maker at Beckmann’s came up with the idea to check the car accessory supplies for gas loaded springs. So, we ended up using automotive pneumatic springs. Here’s an opened view. You can see the perspex cover sliding out to one side and one of the springs. The centre two mirrors are broken up by the extractor fan.
Aquarium Lid

Aquarium Lid

  • The lighting is so efficient, that I can only run it dimmed. The front rows currently run on 45% power and the back rows have 80%. (BTW that reddish T5 turned out to be no use – I am now running this with four identical daylight white tubes).


Our house is a timber-post structure with windows all round, top to bottom. Combine this with the fact that it was built in 1974 and you have an idea how it does on the energy-efficiency scale. It doesn’t even make it to the bottom (albeit I have replaced the windows with new, energy-efficient ones). This means we keep our room temperature at a cosy 17°C in the winter (come to think of it, we never seem to come down with anything much, so that’s a positive side-effect). However, as a result of that, I had to think of an efficient way to heat my tanks.

Since I didn’t want a heater inside the aquarium proper, one option I had was to stick the heater in the filter. In that case, the heated water would pass through the piping, the UV, the CO2-diffusor and the chiller before it got fed back into the tank. Bad idea. The warmth of the water coming directly from the heater would limit CO2 uptake. If any of the warmth was still detectable after passing the the whole system including chiller, that is. The chiller, despite being off (because it is controlled by the GHL computer) would still disperse the water along its cooling ribs. So that was no option, really. The other idea was a standard external heater. Most of those were too weak to deal with my incessantly low room temperature during the winter months plus they would simply take too long to heat up the freezing cold water after changing. (At the time I was using rain water from an outside vat which, if it wasn’t frozen, would be near 0°C when it entered the tank).

So, I went for something larger, an ELECRO flowline heater. ELECRO agreed to modify it for me and I had one delivered without the temp controller. It sports a whopping 1000W heater element and can be mounted in-line and, more importantly, outside of the aquarium. Unfortunately, this heater has a flow switch which will prevent the heater from working if the flow was under 1000l/hr (if I remember correctly). That was just a tad too much for me so I had to bridge the little switch, which was easy enough to do.

ELECRO Flow Line Heater

ELECRO Flow Line Heater

So that’s water heating.

I touched the topic of whether substrate heating is beneficial or not before but at the time when I designed this aquarium cabinet, I had not abandoned the idea of heated aquarium soil. However, by no means did I want any cables inside the aquarium. They can become a real nuisance. If you have to uproot a large plant such as a mature Echinodorus you are likely to pull up the heater cable along with the plant’s roots. So, I decided to go for a more powerful heated cable instead of a low-powered one and instead of attaching it inside the tank, I decided to place it underneath the bottom glass plate. To accomodate the cable, I needed to have it run inside a groove. Since I also wanted to have a padded layer between the tank and the cabinet, we stuck the padding on first and then had the groove routed in with a CNC work centre. The result is thus:

Heated Cabinet Top

Heated Cabinet Base

When I told friends about this idea most everybody said that they would advise against it because the bottom glass plate would crack due to the heat. I was also warned that the glass was a bad heat conductor. So far, nothing has cracked and the soil in the tank is nice and warm. Touchwood.


In a planted aquarium with ample light, you’ll always get heat peaks during the summer. This means you’ll have to either attach a fan (can’t do that in a closed tank) or keep changing the water. Since I am occasionally away from home for several days, that was no option either. When I designed this aquarium, Arcadia just came out with a new external compressor chiller. It was slightly smaller than most types I had seen before and hence I decided to incorporate the chiller in the cabinet. I wasn’t too keen on the noise or the design of the contraption, so I designed the cabinet with a hidden compartment so the chiller could sit behind the switchboard. Here’s a photo-montage of how this works:

Chiller Montage

Chiller Montage

Since the chiller sits inside the cabinet, we had to make sure that air could be exchanged freely around the chiller. We made one large vent in the back panel behind the chiller unit and one in the door (visible in the image above). It soon became clear that we needed to help the circulation along a bit. Consequently, we placed a second extractor fan right behind the lateral vent. The ancillary fan comes on when the chiller does because they are both controlled by the same I/O switch in the GHL computer. It works absolutely flawlessly and outside temperatures have completely seized to worry me in the summer.


I use the same equipment I use in all my tanks: Hörman CO2 diffuser with a magnetic valve attached to a controller and pH probe. Can’t beat a stable pH in the tank, because I’m not the bubble-counting type.

The Switchboard

I know I did push the boat out a bit here but I love the switchboard in my first tank – no fiddling with plugs, everything is neatly bundled in one place. So, not surprisingly, I wanted this in my new tank as well. The whole thing is housed behind the door, together with the GHL computer and the dosing unit:



Thanks go out to Uwe, a resourceful sparky in my family. He made this a work of art. The whole switchboard can be pulled off (hence the two handles) and the faux back panel removed for access to the chiller. The cables all come together in one big so-called “Harting-Plug” which can be pulled off the back of the switchboard panel for maintenance.

I went for two dosing pumps here because I wanted to be able to dose macro- and micro-nutrients independently. Since you cannot mix them up, it had to be the two pumps. The fertilizer is fed directly into the piping system. Thanks go out to Alwin Hörmann, who was kind enough to make this piece of custom pipe for me.

Here’s a gallery of images from my tank number 2:

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