Category Archives: Paludarium

Keyhole Cichlids built a nest!

What I noticed in the past few days was the keyhole cichlids (Cleithracara maronii) were very aggressive to the other fish. As they have never done this before I decided to investigate.

Building a nest

What I saw today was that two of the Cichlids were very close together. On a rocky surface in the back I saw around a hundred tiny white dots, and both cichlids constantly at that same spot. I became clear to me: The keyhole cichlids are having babies!

A keyhole cichlid defending its eggs that were laid on a rocky surface near the filter drain.

A keyhole cichlid defending its eggs that were laid on a rocky surface near the filter drain.

Both parents show a lot of care for the eggs. Read more »

Video: Splashing tetras laying their eggs in the Paludarium!


Why are they called “splashing tetras”? You’re about to find out in this post :)



Copella Arnoldi: Meet the splashing tetra!”

The splashing tetra is a fish that was sick of other fish eating their eggs. So they thought of a very smart thing to keep the other fish from eating their eggs: They lay their eggs ABOVE water, not in it!

Easier said than done… It requires them to jump out of the water, lay the eggs on surfaces above water, fertilize the eggs and then manage somehow to keep them wet until they hatch… And the splashing tetra did all of that.


How they lay their eggs

So how do they do all of this magic? As the female is getting thicker and thicker, it becomes clear she is producing eggs. The males start courting her, and at some point they form a couple.

The male now starts “test jumping” to several objects, mostly leaves growing above the water surface. They can jump up to 10cm:

Splashing tetra male jumping out of the water to test out places to have their babies hatch

Splashing tetra male jumping out of the water to test out places to have their babies hatch

After a spot has been determined, both male and female line up just under the water surface. By gently “buzzing” their bodies they communicate with each other and synchronize the jump they’re about to make:

Getting ready to jump... They must jump together and this requires a very exact timing.

Getting ready to jump… They must jump together and this requires a very exact timing.

Then they’re off! They both jump out of the water, and this picture clearly shows how well synchronized they are when they do:

Both male and female splashing tetras jumping synchronously out of the water to lay their eggs.

Both male and female splashing tetras jumping synchronously out of the water to lay their eggs.

When they hit the surface where they’ll be laying their eggs, they will stick to that surface for a second. The female lays her eggs while the male will fertilize them:

Splashing tetra male and female sticking to a leave above water to lay and fertilize their eggs.

Splashing tetra male and female sticking to a leave above water to lay and fertilize their eggs.

After they have laid some eggs, they’ll fall back into the water:

Male and female splashing tetras falling back into the water after laying egss on a leave above the surface.

Male and female splashing tetras falling back into the water after laying egss on a leave above the surface.

They will now repeat this until they have laid between 50 and 100 eggs.


New babies about to be born!

Now this is where the splashing tetras get their names from. The eggs that were laid above water need to be kept wet. This is why the male splashing tetra will stay with the eggs, and splash them with his tail every few minutes! They have an amazing aim in doing this. I was lucky as the tetras at some point laid eggs on the side window: The next video shows both the splashing, the eggs up REALLY close (each eggs is only 0,2 mm in diameter!) and the eggs getting splashed:

Some longer closeup video of the actual eggs:

After three to four days the eggs hatch. The baby fish start their lives with an 8cm daredevil drop into the water! That is like base jumping without a parachute considering they are only 0.3mm in length. When you’d compare that to a human, it would mean that a new born baby would drop about 145 meters then hit the water :P

Once the babies have hatched, they are very small fish that hide between leaves and roots of water plants:

Baby of a splashing tetra

Baby of a splashing tetra

And in real closeup:

Closeup of a splashing tetra (Copella Arnoldi). These fish are only about 0,3mm long right after they hatch!

Closeup of a splashing tetra (Copella Arnoldi). These fish are only about 0,3mm long right after they hatch!

Sensirion SHT-11 humidity and temperature sensor ready to go!

One of the sensors that can be read by the Neptune module is the Sensirion SHT-11 I have had laying about for years.

Now finally it is ready for use! The sensor sits on the end of a 2,5 meter cable which is soldered on directly. A small capacitor is glued on as well to cope with the excessive cable length. The sensor in its entirety is covered in a drop of silicon glue to keep the moisture out of the electronic contacts. This sensor will be measuring over 98% relative humidity at times!

The Sensirion SHT-11 sensor glued into a drop of silicone. This digital sensor measures air temperature and relative humidity in the Paludarium.

The Sensirion SHT-11 sensor glued into a drop of silicone. This digital sensor measures air temperature and relative humidity in the Paludarium.

So far the results are looking good. This is the sensor still hanging in the living room:

sensirion

22.24 degrees centigrade and 65.94% relative humidity. Sounds realistic as it’s a very moist day.

When the silicone had dried, I put the sensor inside the paludarium. After settling it showed measurements like these:

Measured values when the Sensirion sensor is inside the Paludarium.

Measured values when the Sensirion sensor is inside the Paludarium.

Great! Tempereature at 23.16 degrees, relative humidity at 87,61%. Very Jungley :)

What I did find out, is that the location of the sensor heavily influences the measurements. Especially the humidity is VERY dependent on where you measure.

Neptune module taken into action

Finally. After a long time building the hardware and the software, the Neptune module is the final module to be added to the Paludarium.

This module is a more complex version of the Apollo units that live inside the Canopy that control lighting and fans. The Neptune module has some control for lighting (namely the underwater lights), but its main purpose is controlling pumps and valves, and measuring back sensors in the paludarium.

For now the Neptune module is setup in the cabinet under the Paludarium:

The Neptune module sitting in the cabinet under the Paludarium with some sensors already connected. What a mess of wires and hoses!

The Neptune module sitting in the cabinet under the Paludarium with some sensors already connected. What a mess of wires and hoses!

The unit has been running for over two weeks now without a single flaw… I must be doing something right ;)

Video: The first real Thunderstorm

After running some tests, today for the first time there was an actual thunderstorm in the paludarium!

How the paludarium figures there should be a thunderstorm

I could have made the weather inside the paludarium choosen by random, but that wouldn’t have been any fun. Instead, the paludarium fetches live data from the La Selva Biological station in Costa Rica.

Using a 1,5 day delay this meteorological data is “replayed” inside the paludarium. Why 1,5 day? Well, one day to Read more »

The stuff Paludariums are made of

People are often confused what things are all in the paludarium, what they are called and what they do. In this blog post I’ll explain the different components (sub projects if you will) that make up the paludarium today.

A quick overview

In order to get the paludarium working as it works today, I had to run several different projects and put them all together. First I’ll quickly list all the different components:

  1. The Cabinet – The custom-built cabinets that hold the paludarium;
  2. The Paludarium – The glass structure that holds water and air (the paludarium is a closed construction);
  3. The Land part – The part above water. Filled with tropical plants, and for now no animals here;
  4. The Aquatic part – The front underwater part of the paludarium, where the fish live;
  5. The Sump – The rear underwater part. Any excess water from the Aquatic part is dumped here, and the plants living on the background panel get their water from here (and return it there too);
  6. The Waterworks – The board in the cabinet that holds all the plumbing (water valves etc);
  7. The Canopy – The intelligent armature sitting on top of the paludarium;
  8. PaluPi – A standard Raspberry Pi with an RS232 level converter that sits inside the Canopy and handles all the “smart thinking”;
  9. Apollo units – Named after the god of light, there are around 12 of these units inside the Canopy, each handling up to 4 leds, halogens, TLs or fans;
  10. Neptune module – Still under development, this unit controls all pumps, valves etc in the Waterworks;

Quite a list right? Everything in this list had to be tuned Read more »

Paludarium planted!

Just a quick post to show of the new plants in the paludarium! I just finished planting the non-aquatic plants, and I am very happy with the results:

non-aquatic part planted as well!

non-aquatic part planted as well!

I could not resist this VERY cool orchid when I saw it in the shop. Hopefully Read more »

Bringing all technology together

As the paludarium slowly got all parts in place, I set myself a goal: I wanted to have it filled with water on my birthday! That proved to be a LOT of work; but it paid off! In this blog post I’ll show you the final tidbits that made the paludarium ready to contain water.

background and waterfall

The background now has two layers of epoxy where I poured this jungle soil over the epoxy. The result is almost covering the background, and not that much white is showing (from the styrofoam). Now it was time to glue the background in! I used aquarium silicon glue for this:

The background being glued in place. Note the stick under the background to make sure it stays in place.

The background being glued in place. Note the stick under the background to make sure it stays in place.

Note the stick that holds the background in place while the glue dries. With that done, it was on to Read more »

Building the Backgrounds using Epoxy resin

After a really busy time, I finally have had some time to work on the paludarium once more. This time I have started working on the various backgrounds using epoxy resin.

Preparations

Preparing to work with epoxy resin isn’t that hard, but you need to sort out what you will be doing and have all tools required at hand: The epoxy resin starts to set within an hour, so once you have mixed up the components you need to be ready to go. This is what I used:

Preparing for the first epoxy resin layers.

Preparing for the first epoxy resin layers.

It is VERY important that Read more »

Taking a chance: Adding lianas to the background

Sometimes you have to take a chance. I wanted some realistic roots worked into the background (above water). But how to find nice pieces that will not rot too quickly?

Contestants for a wooden background above water

I have been looking at a lot of different types of wood to use in the background on land. The wood should not rot too quickly, so my first thought was to use driftwood, or rather the sinking type used in aquariums all over the world.

But it proved to be very hard to actually find pieces that Read more »