# "Heart of Darkness" cube diary, step-by-step. (56k, sorry...).



## erik Loza (Feb 6, 2006)

*The Concept*: I always thought the idea of a naturally-lit aquarium was intriguing. It would cost nothing to light, would have a a natural color balance, and would lend an airy, open feel to the room.

*The Plan*: Install a solar tube skylight in this dark corner of my entry hallway so that guests would see a beautiful planted aquarium when they first enter my home.

*The Hardware*: 10" solar tube skylight from suncowboy.com, 18" Oceanic cube tank (about 25 gallons), matching stand, Eheim 2213, 100w submersible heater, electronically controlled CO2 injection system, DIY reactor.

Installing the skylight...









Getting the tank put together...









A quick word about the tank decor. I prefer to use decor that I have collected over just buying stuff whenever possible. I often see things when I am hiking that strike me as having potential in an aquarium or terrarium and make a mental note to remember the area for future projects. This gravel was collected from a local creek. Notice the very interesting little clam shells mixed in. Such things are fascinating to me. It was poured over a layer of Ferti-plant and laterite that I had left over from the big tank...









Same story with the driftwood. Here is the day's haul from a local river and most of it seems to be old Bald Cypress, which is a common tree in riparian areas here of the Texas Hill Country. I saw these pieces down among the rocks on the bottom and swam down to bring them up...









There are many interesting local aquatic plants here and that's another tank for the future. This moss was growing in a shaded pool and I thought to bring some back and see how it would grow. I believe that is a species of _Fissidens_, but perhaps someone more knowledgable could comment?









Decorating the tank: There were some oddball _Pelvicachromis_ at the local fish store that I had been watching and thought a West African-themed tank, with _Anubias_ and mosses would be interesting. My local Petco had a pretty good supply of _Anubias barteri_ at $4 each, so I bought a bunch.

The tank required some custom fabbing of the Eheim spray bar, due to its tight dimensions and tall geometry...









Now that it has been shortened, the exhaust ports get enlarged and a second set is drilled, to force water down and across the bottom of tank...









Here is the plumbing, installed in the tank. The CO2 reactor is on the left, Hagen high/low skimmer in the middle, and spray bar on the left...









Trying to find an arrangement that worked with the driftwood was tough. This one did nothing for me...







. I finally arranged them in the form of a tree stump rising up from the gravel bed and it is much more interesting.

Organizing the plants...









Attaching the Java Moss and _Fissidens_ to stones with hair nets. These are almost spider web-like in thickness and invisible underwater...









Everything went together fine and I was in a hurry to wrap it up, so didn't take any photos of it immediately after the install. The tank is now four weeks old and doing great. The _Fissidens_ has thrived and looks buff in the tank. The pool where I found it is seasonal and has dried up now, but I will collect more next year and do an entire tank dedicated to it. The Kribs haven't spawned yet, but should soon. The dither fish are Emperor Tetras, Five-banded Barbs, and a few _Corydoras lonozonus_. Due to its low light level, no algae eaters are required. Here are the 1-month photos...














. The Dwarf Peace Lilly is growing there hydroponically and hides the heater and filter equipment. It also breaks up the somewhat formal, cubed look of the whole package.

_Fissidens_...









Java Moss...









Though I'm really happy with it now, the install was not without its issues. The light provided by the solar tube makes a nice ambient light but was nowhere near bright enough to grow even the _Anubias_ or mosses, so a 28w fixture was installed. So, it's officially about 1w/gallon running 12 hours per day. Also, my DYI in-tank CO2 reactor was poorly designed. The plenum was too large for the powerhead I installed and the CO2 bubbles were escaping the vent hole before being shredded and exhausted into the tank. Furthermore, due to a bad install on my part, I emptied a goodly portion of my CO2 tank (leaking at the regulator, intead of into the tank, thank goodness!) before figuring out what was happening. In fact, I've been so busy doing other stuff that I haven't rebuilt the reactor or hooked up the CO2 tank again. The plants are doing great, so I may just leave it as-is and use the system on some future tank. Anyway, hope you enjoy and good luck to all.


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## Zapins (Jul 28, 2004)

Wow nice looking tank. Very interesting idea with the solar tube. Maybe it could work if you got some fiberoptics and some lenses to focus the light into the fiberoptic cable, then you could use the cable as a lighting source.

But that’s probably too much of a hassle 

Great job with your tank design by the way. It really looks good.

I think that is fissidens as well. Too bad I can't get any of it up here in CT 

What is your dosing schedule like?


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## finfollower (May 27, 2004)

that's very very impressive and the tank is looking great!


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## John P. (Nov 24, 2004)

Neat project and accompanying documentation.


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## Rand (Jan 23, 2005)

Awesome work, Erik. I was imagining this kind of set up before where natural sunlight hitting mirror-like panels and beams to an aquarium tank. This will reduce the amount of electricity a person use I thought and create more natural ambiance.

The substrate, stone and driftwood you found was also impressive. Even more impressive is the _Fissidens_ you found. That is a great find!

Seeing how you built this tank is very enjoyable, thank you for sharing your experience.

Randall


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## daeraion (Oct 25, 2005)

Is that a spathiphyllum peeping out of the back of the tank? And if so, are you hydroculturing it?


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## eklikewhoa (Jul 24, 2006)

that's awesome looking!!


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## kelliope (Apr 13, 2006)

Very cool!!! I have that same tank, but it is nowhere near as cool as yours! Good job.


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## heidisue (May 3, 2006)

I love the scape - it looks like an underwater centerpiece. Very curious to see how it looks at the end of the summer (and beond). I also just started a new tank using mostly sunlight and the plants grow very differently. It's fun to experiment. Thanks for the step-by-step, too!


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## erik Loza (Feb 6, 2006)

Yes, that is some dwarf form of _Spathiphyllum_ that I found at the local Lowe's, growing hydroponically. I read somewhere that emergent plants use organics in the water at a rate something like four times that of submerged ones, so I hope they're doing some denitrification. Regarding ferts, I pour half a capful of Seachem Flourish into the tank each weekend. Thanks to all for compliments. There is a third tank that will be similar size in progress and I will post when that gets done.


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## istellas (May 9, 2006)

Great job with the solar tube and the aquarium too


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## ChiDONEt (Sep 16, 2004)

Erik: Please post your result or send me email with your comments about solar tube, I want to put these system (Solatube México : Everlux) for a new tank


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## bpimm (Jun 12, 2006)

Great job on the tank, very pleasing to the eye.

I have always liked the solar tube idea and thought that building a soffit above the tank to bring the interior lens down closer to the top of the tank would be good; also maybe a fresnel lens from a overhead projector instead of their diffuser might help to focus the light down into the tank.


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