Maybe Making a Mini-Monster for Mbuna

[M1A1]

I have been mostly a saltwater or freshwater community tank guy but now I have the opportunity (space) to get back into DIY tanks and want to do that with a mixed gender mbuna tank. That opportunity has some limits though so this will have to be a mini monster tank build that might end up being the wrong dimensions for mbuna and that's where I'm totally out of my element.

Based on lots of reading and mostly cribbing notes from DJRansome, the stock list I am interested in is any/all of:

Labidochromis caeruleus​

Pseudotropheus cyaneorhabdos Maingano​

Pseudotropheus acei​

Metriaclima callainos Kirondo​

Iodotropheus Sprengarae​

The space limits me to a tank no larger than 168" (not a typo, 168 inches, 14 feet) by 18" in footprint but the catch is the height - the tank and stand can't be any taller than about 32" plus I need about 14" of clearance in the stand for stuff. That leaves 18" max total tank height, subtract 1" for the bottom panel, subtract 1" for the top bracing, and maybe subtract some more for a slim canopy or cover... Maybe 15" or 16" of water depth before substrate. If I had to build the tank today then it would be even lower as I happen to have a pair of glass pieces that are 78" by 12" which I could stretch to about 13" or 14" water depth. Subtracting some length & width for construction, it'd be a roughly 150 to 170 gallon display tank with a 13" to 16" water depth, respectively.

So, will the rock fish listed above enjoy this potentially very shallow reef-type tank? How much swim room should there be above the rock work?

 

[DJRansome]

In a 14 foot tank there are few rules...even if only because there is not a lot of data from people with experience with tanks longer than 8 feet with mbuna.

Your list looks good to me and I would want a lot of fish to manage aggression...maybe 80 individuals.

You can take the rocks right to/through the waterline but most of us can't get quite that high. Make sure to leave isolated patches on the substrate for the males to claim/defend.

Definitely cover the tank. Add rocks first, then substrate and I like no more than an inch.

 

[M1A1]

I will probably have lots of follow-up questions on this so apologies ahead of time. I think I estimated at least 70 fish based on reading (Mary Bailey's formula) so 80 certainly sounds reasonable. That'd put it at 16 fish per species on the list if divided evenly? Only the Maingano are in my notes in terms of the number of females (1:7 minimum instead of 1:4?) but I'd far exceed where that's relevant? Should this be a single male per species with the rest female?

 

[DJRansome]

In such a large tank...one male/group or three males with 3X the usual # of females...so maingano 3m:21F. I would just play it by ear...just avoid having 2 Maingano males. One or three or more. Not two.

 

[jjohnwm]

I know diddly-squat about Africans so excuse the perhaps-silly question, but...do Africans need substrate? If they aren't diggers and eartheaters, why not just forego the substrate altogether and gain back another inch or two of water depth? You can use ceramic tiles on the bottom, which can be had in numerous earthy tones and patterns and textures. Or even perhaps smear silicone across the entire bottom glass and then just sprinkle it with a thin coat of sand or fine gravel? Just thinkin' out loud here.

Even if you use your current 12-inch glass pieces, you could still make the tank a couple inches deeper by using a wider frame around the front panel...I'm assuming here that this will be a plywood or fibreglass or other type of build that has a glass viewing panel inset into a window in the front? Totally subjective, I know, but personally I really like the look of a tank where you can see neither the water surface at the top nor a "side view" of the substrate at the bottom.

And if your tank is only 16 inches deep, well, plenty of commercial small tanks are only that tall. Yours may give the illusion of being much shallower due to the length, but with carefully chosen decor that can likely work to your advantage.

Finally, would the placement for this tank allow for lights mounted up near the ceiling, using spotlights carefully aimed to light the tank without flooding the surrounding room too badly with light? That way would prevent wasting any of your 32 inch maximum height on hoods and fixtures. The higher the lights are, the easier it is to get that wonderful shimmering sunlight effect with a bit of surface agitation.

Looking forward to hearing and seeing more on this project.

 

[DJRansome]

They do like to play with the substrate.

 

[M1A1]

Yeah from what I've read, it's not a sand-sifter behavior like the Geophagus but mbuna will move the sand around and spit it out, including gravel & pebble size stuff, and also flash or fan the substrate to kick up food/detritus/whatever? Planning a mix of pool filter sand, fine-grain aragonite, and a sprinkling of larger gravel/pebbles maybe. Depends on what my landscape place has when they open up in the spring as we're frozen solid and snowed in right now.

If I can find better size glass then I would like to go with an aluminum frame with PVC foam sheet as bottom/back/side panels, glass front. Basically a metaframe aquarium. This would simplify things a ton so that's why I'm still looking & asking around for glass. You can find the PVC foam sheet at the big-box stores these days under the Royal Building Products brand. An 8ft by 4ft sheet of 3/8" runs about $80 to $100, the 1" by 4" by 16ft trim is like $15 to $20. You can use normal PVC plumbing glue to bond it or get some more high-test stuff like when working with acrylic. Silicone sticks real well.

If I can't find any better glass then the tank will be plywood shell/structure with PVC foam sheet & trim instead of epoxy & fiberglass. I've been sketching a lot and the thicker frame above & below the glass does get me to whatever height I really want (16"). But it's more complicated than I'd like with extra joints and having the glass off the bottom loses quite a bit of strength. Not that it matters a ton on a shorty tank like this would be.

I'd like to keep this to only two pieces of glass max but I have been watching for tanks I could break down for the glass. Unfortunately anything in the 16" tall range is mostly just 40 breeders and that 36" long glass would be annoying; only gets me to 144" long with 4 panes or 180" long with 5 (I do have some room beyond 168").

Placement of this tank does not allow ceiling lights. The current sketch I'm working on has a plywood 'canopy' about 1" tall which is enough room for some LED strips (DIY) and the actual polycarbonate lids covering the openings in the bracing. I've continued to drop the tank down, shorten the stand, as I have room for filtration on the sides.

I did get a quote back for an all-glass tank that cuts the length down to 140" so at least I have a target to stay under. Look how much money we're saving with DIY!