Jump to content

Mbuna Condos


Recommended Posts

I got a Request for Proposal from the  MRO (Mbuna Rock Owner)Association for the construction of condos in a 75 gallon tank. From the quote:


We are tired of seeing our loved one gobbled up by other fish, we want to come to America and live in a aquarium. We want a condo for all Mbuna which includes running water. 

Running water???

Since I own 75 gallon tank currently being resealed, I decide to make a bid. My first proposal was small cubicles using 1/2" PVC sheets. Here is the MRO association response: 


We are not birds, we are Mbunas! We are rock fish, we want rocks!

OK, no birdhouse build, here is my second proposal. So the goals on this build. The entire bottom of the tank will be covered in rocks. I want to support the rocks above the tank bottom which will eliminate the first layer of rocks and create space for the condos. This will also drastically reduce the weight of the required rocks. 

Here is an executive summary of my prototype:

Place balloons fill with sand and small PVC pipes to support the rocks in a form.


Wrap rocks with Saran wrap.


Mix foam and pour into form with rocks in place. Yes, that is a tombstone on the left side, been busy making props for our neighborhood Halloween party. We do a haunted hayride.  

Remove balloons


Cover exposed areas of foam with Gorilla glue and pack substrate in form. In the actually build, I may use silicone caulk. 




With one layer of rocks and sand.


Add second layer rocks. I am quite happy with the results, this was a quick prototype. For the actual build, I need to raise the rocks higher so the condos go more under the rocks instead of between them. I also need to work on how to slope upwards with a possible rock wall on the back. I would like to get at least 20 condos in the tank. For the actual build, I will use a full size form so I can lay it out first. 


Now what I didn't show, result from a second ouring of foam to fill in spots. Clearly that didn't work but the foam can be cut easily.


Working in small section at a time, I need to make this with a single pouring of foam. Above is what I want, nice rounded features which looks natural. So my plan for the build. Remove the rocks before the foam pouring, I should be able to evenly pour with no rocks in the way. Then quickly put the rocks on the PVC pipes. This has to be done in about 10-15 seconds, the foam is very reactive. And clearly, I need to work in small sections at a time.

I am happy to report, the MBO Association have accepted my proposal. I did express my concern with aggressive behavior from Mbunas defending their condos, the MBO replied:


We are Mbuna, that is who we are.

Hopefully I will have time to work on it as I am finishing up my tombstones for our annual neighborhood hayride. 


I decided on a 27 Club  theme, the guitar strings need to be covered with Monster Mud.  Below will go on the Mama Cass tombstone who is not a 27 club member and died from a heart attack but I had to do it. 

Edited by madmark285
  • Love 4
Link to comment
Share on other sites

  • 5 months later...

Just an update, I finally back on this project. Here is a general layout of the rock structure I will be using. Not shown is this photo, the supporting PVC structure to hold the rocks and create the condo, thats next on my agenda.


So the rocks are laid out in a semicircle, there is a open space on the front and side walls. The gap you see between the rocks will be the entrance to the condo which are under the rocks. This whole structure will be ~3-4" off the bottom of the tank.

 Common feedback I am getting from many...

When a male Mbuna goes rouge and start terrorizing other Mbunas, I should not expect that the terrorized Mbuna will or can hide in a condo to getaway. My current design is a 3 story condo complex where us human would claim a condo for protection. This may not work with fish 🙂. So does using all the space for 26+ condo really make sense?

So what I can do. In the mold I made to build this, pack sloping sand along the front and sides shown below:


The sand acts as a mold for the expanding foam, the opening you see here under the rock will be foam. So this will create a ledge surrounding the rock structure for the condos. Kinda like a moat around a fort. I hope this helps in the line of sight issue, a terrorized Mbuna can swim under the ledge to get away from a rogue male.

So the bottom line, this will reduce the number of condo's but create a common space where I hope any Mbuna can hide out. Any thoughts will be appreciated. 



  • Like 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Create New...