Before you start setting up the Interior of the Brackwater Aquarium, you have to make sure that no Metal pieces come into contact with the Water.
The salt in the Water, will come into contact with the metal (even Aluminium), and cause a reaction, and unleash highly poisonous particles into the water.
Puffer Fish are extremely sensitive to Metal !! The exception would be a special VA Steel, wich is used for Ocean Water.
For the Aquarium bed (floor) it is best to use Sand. Most Puffer Fish love the soft floor, and it has its advantages regarding the Biology of the Aquarium.
It is important, that the Sand isn‚€™t too fine, or else it would harden too easily.
Normal Building Sand which can be purchased from D.I.Y stores is a good choice.
It is usually free from any additives (but ask beforehand) and also very reasonably priced. You can also use River Sand with not so much pebbles in it. Just make sure the finer Sand is
rinsed out first.Coral Sand is an eye catcher, but very quickly becomes infested with Algae.
You should use that for See Water or very heavy Brack Water.
Picture: Sphoerides testudineaus, A Sea Water species, can be kept in Brackwater as a juvenile. As you can very clearly see, you need Sand for the Aquarium Bed.
Puffer Fish, often have a territorial behavour and the Aquarium should be very well structured and organized. This is where the different Aquarium rocks and different stones, come in usefull.
The white holed Rocks are often used in Brackwater Tanks. Because it is very good for stacking on top of each other, and it keeps the water or the PH level stable, through its high Lime level. You could also use Slate and Granite in the Brackwater Tank. Stones with Metal insertions should be avoided. The reasons for that is explained previously.
Different types of wood can also be used. The usual types of Aquarium wood like Moorkien ( to be waterd a while beforehand, so It doesn‚€™t go sour) Mangrove or Mopani.
The water can cloud a little, which isn‚€™t dangerous and it only happens when too much wood is added into the Tank.
With Stones and wood, the Aquarium can be structured very well, to create Hiding holes, and low lying places.Rather a little too much, than not enough!
A Brackwater Aquarium isn‚€™t dependable on high growing plants. Algae are the most important. And if the right water quality and pleanty of Lighting is available, and you get a great Algae growth, it will look very nice! With the right Lighting and a little Luck, some very nice Red and Green Algae should grow. If you have a good water current, you might be able to see Thread Algae grow.
Higher Algae, like the Caulerpa from Ocean Water could possibly work too. There are also some very nice Leaf Algae from the Brackwater, which are, because of lack of Interest , hardly available anymore. With a Light Brackwater you can try it also with a Java Fern (Microsorum). This is a very compact Plant and has been known to last longer. Also, some Cryptocoryne species can work. The C.ciliata for instance, can even stand very high Salt levels, if you let it get used to the water properly.
For a Brackwaterpaludarium, one can use Mangroves, which, with the right Lighting, grow slowly but constant. Apart from that, you just have to experiment.
Scandent Ferns and Java Moss can work too, red and fine leafed Types are not usable at all.