Low tech dirted Dennerle 30l cube

[hydrophyte]

Hi all! I’ve been on-and-off lurking in this forum for years and decided that, with this new tank, it was time to take the plunge and document it in a journal.

I’m setting up a Dennerle 30l cube that’s been sat in my garden for about a year after a break from the hobby. Plan is for a low tech heavily planted dirted tank full of microfauna that will eventually house some Indostomus spp. which are (imo) some of the coolest fish in the world.

View attachment 217081
(Pic from a previous ill-fated attempt due to using uncapped soil and not giving the tank enough time to mature before getting the fish. Not going to make that mistake again!)

Really nice project!

I have pondered a similar concept that would use a second tank enclosure just as big as the main aquarium display, but holding a planted area with reverse-schedule lighting as well as media baskets with lots of surface area for both microfauna and bacterial biofilm. This setup would further have slow water recirculation between the two tanks, with the second one providing both live food and CO2 for the planted display. Now that you've reminded me about this, I might have to revisit it.

 

[AlStu]

I have pondered a similar concept that would use a second tank enclosure just as big as the main aquarium display, but holding a planted area with reverse-schedule lighting as well as media baskets with lots of surface area for both microfauna and bacterial biofilm.

This sounds like an awesome project!! I’d love to see a journal for it if you decide to go ahead.

I’m hopeful with this one that as the Indostomus are so tiny, they won’t be able to eat the adults and I’ll be able to sustain a population within just this little tank, but I’d love to try with an internal refugium (think modified filter compartment) that overflows into the main tank a few times a day for other slightly hungrier species like scarlet badis!

 

[AlStu]

Making some progress. The microfauna in the tank is still a great source of joy, I spend so long watching the snails, Moina and Ostracods go about their business you’d forget the tank hasn’t actually been stocked yet.

(Full tank shot showing a little but not loads of progress)

Plants are going ok. The Ludwigia and H. lancea I put in have all but melted away, so I’ve consolidated them into two corners of the tank. I suspect this is down to the lack of flow in the tank, as there was lots of rotting internodes, but it may also be nutrients related (more on this later)

(Sad Ludwigia pallustris)

(Sad H. lancea)

In terms of growing conditions, I’m pretty sure the light is bright enough (although is may be the wrong spectrum as it’s for house plants) and if it isn’t bright enough I’ve realised I don’t want to go brighter as Indostomus are very much a shady tank fish. Floaters are all proliferating rapidly, the red root floater is going a bit orangey (yay!) but there’s some solid chlorosis on the water lettuce. I’m pretty sure the nitrates aren’t less than 5ppm, so I suspect the redness is either phosphate deficiency or that the light is actually quite bright. RE the chlorosis, I suspect iron deficiency, especially as I have hard water and it didn’t go away after adding some ferts. I’m going to try dosing 4mm a week of Tropica specialised (just less than 2x recommended dose, which I’ve read is quite lean) and see what happens. If it persists I’ll also add some TNC Iron and see how that goes!

(Floaters, note that I’ve removed the very red original RRFs)

I’ve had some very compact new growth from the H. corymbosa, but this also looks a little chlorotic in places, which is interesting given the fact it’s in soil. I’ll see how it reacts to the updated feed regime!