I finished building my deep sand bed for my sea floor biotope setup any tips are appreciated

[Urchin boy]

Today I bought 40 kilograms of sand to add to my recently cycled saltwater aquarium and I have been experiencing the first stages of the ugly stage currently at brown diatoms and so far my test results show that nitrate and nitrite levels are very low which is very good and I calculated I would need to add this amount to increase my sand bed from about 6 centimeters to about 10-13 centimetres which should be enough to host my deep sand bed .

I also ordered some caluerpa prolifera macro algae to provide additional hiding spaces besides my lava rocks and the sand bed itself and in addition I ordered a nassarius snail and plenty of deep sand bed critters including both amphipods and copepods rotifers and also some blackworms to help stir the substrate and keep my deep sandbed healthy.

As you can see I used completely natural Quartz sand which is why the water is so cloudy but this will go away on it's own and as my tank is completely empty besides my rocks and sand I don't care about rinsing it first and this will be the final sand layer on top of several lower layers of sand with various sizes and the reason I did this was to provide my inhabitants a more realistic environment that is more like that of a real ocean sea floor complete with deep sand and plenty of rocks.

It is possible I might add some candy corals in the sand bed to further improve the looks but I am so far not at all interested in corals only the sea floor and the critters that make it their home hence why it's a sea floor biotope with only Carribbean species that would occur naturally focusing specifically on sand dwelling animals and invertebrates like sand dollars worms and snails or Jawfish.

This is what my tank looked like before adding the sand and for anyone asking yes I removed the rocks before adding the new sand.

 

[Lavey29]

So this is interesting. You want to introduce sea critters that make their home in the deep sandbed of the ocean. How will you ever see these guys in your tank if they prefer to be covered. Will you just be looking at water andb6 inches of sand?

 

[Urchin boy]

So this is interesting. You want to introduce sea critters that make their home in the deep sandbed of the ocean. How will you ever see these guys in your tank if they prefer to be covered. Will you just be looking at water andb6 inches of sand?

Eventually I will start to see small holes develop in the sand due to worms and snails digging and I do plan to add Halloween hermit crabs later to add some variety as well along with a pair of yellowhead Jawfish as they like to make burrows especially when the father has his young to protect in his mouth

 

[Lavey29]

Eventually I will start to see small holes develop in the sand due to worms and snails digging and I do plan to add Halloween hermit crabs later to add some variety as well along with a pair of yellowhead Jawfish as they like to make burrows especially when the father has his young to protect in his mouth

An interesting approach to a reef tank

 

[Urchin boy]

An interesting approach to a reef tank

Very much so as it focuses on a part of the reef that is just as important as the actual reef itself but it is sadly under explored in the hobby where the focus is almost always on corals and building reefs not what lives under it

 

[darrick001]

I did this about 15 years ago just to see what happened in the sand bed. The issue your going to run into is there is not enough of the sand bed getting dug up to keep it healthy. Your going to get black decaying areas that form. When your animals move and dig up one of these areas it can release some nasty gasses. I resolved this by adding a plenum under the sand. I connected all the pipe underneath so it was sealed. 18- 3mm holes were drilled evenly distributed so that water could flow at a very slow pace. 1 vertical tube was connected between the plenum and a T at the top of the water. A piece of ridged airline was ran about 1/2 way to the bottom of the vertical tube. A small air pump with a gate valve was used to move about 20 gallons an hour through the sand bed. This kept the sand bed clean no black spots appeared in the sandbed and the critters were moving through the sand bed top to bottom. Pods and worms were even living in the plenum. Prior to the plenum the critters only occupied the top 25-50mm. I know this is against common thinking but I did a lot of research trying to solve this issue. This is what worked for me. It worked so well I implemented this on my current tank and it has worked extremely well. 10cm sand depth.

 

[Urchin boy]

I did this about 15 years ago just to see what happened in the sand bed. The issue your going to run into is there is not enough of the sand bed getting dug up to keep it healthy. Your going to get black decaying areas that form. When your animals move and dig up one of these areas it can release some nasty gasses. I resolved this by adding a plenum under the sand. I connected all the pipe underneath so it was sealed. 18- 3mm holes were drilled evenly distributed so that water could flow at a very slow pace. 1 vertical tube was connected between the plenum and a T at the top of the water. A piece of ridged airline was ran about 1/2 way to the bottom of the vertical tube. A small air pump with a gate valve was used to move about 20 gallons an hour through the sand bed. This kept the sand bed clean no black spots appeared in the sandbed and the critters were moving through the sand bed top to bottom. Pods and worms were even living in the plenum. Prior to the plenum the critters only occupied the top 25-50mm. I know this is against common thinking but I did a lot of research trying to solve this issue. This is what worked for me. It worked so well I implemented this on my current tank and it has worked extremely well. 10cm sand depth.

Sounds very interesting as I previously used a undergravel filter in my freshwater aquarium a few years ago which is not the same but there are similarities. I definitely need to do some research about how to do this as I have heard about this being used although I have no idea what supplies I need besides obviously pvc piping.

I would like to know how you setup this as I would want to install this preferably before I add my livestock

 

[darrick001]

20-25 mm pipe.
Pipe on the bottom
Egg crate
Screen fine enough to keep sand from filling plenum
25mm of sand
second layer of screen. This can be 3mm just To keep jawfish from digging all the way to the plenum
100 mm of sand
You want about 12 mm of space between the glass and plenum to allow sand to hide the plenum
Wrap the bottom layer of screen over the sides of the plunum extendong 50 mm under the plenum
Sorry my computer is down right now so I had to draw on my screen.
You do not want much flow through the sand. It's not a filter it's just enough to keep it oxygenated. You don't want it pulling lots of waste into the sand bed.

 

[Urchin boy]

20-25 mm pipe.
Pipe on the bottom
Egg crate
Screen fine enough to keep sand from filling plenum
25mm of sand
second layer of screen. This can be 3mm just To keep jawfish from digging all the way to the plenum
100 mm of sand
You want about 12 mm of space between the glass and plenum to allow sand to hide the plenum
Wrap the bottom layer of screen over the sides of the plunum extendong 50 mm under the plenum
Sorry my computer is down right now so I had to draw on my screen.
You do not want much flow through the sand. It's not a filter it's just enough to keep it oxygenated. You don't want it pulling lots of waste into the sand bed.

I am not sure if I would need to remove my sand and gravel first before installing it which would take a rather long time also I am really struggling to find more resources on doing this outside of ancient forum posts that are over 15-20 years old

 

[darrick001]

The plenum is old tech and really never worked the way they thought it did. I wouldn't go by the old posts. The information that inspired me to try this was actually from college studies on water treatment.

 

[darrick001]

Lots of people run deep sand beds without using this. I may be the only one using it this way. It is not a tried and tested method. It is experimental and my information is from my own testing and observation. The plenum is just a deep sand bed and works the same way. The plenum on my setup is only to allow water to flow through the sand bed and not plug the holes. It just eliminates the bacteria gases so it's not released when the digging animals disturb the lower sand areas. My tank was designed to house a blue dotted jawfish and eliminate common issues caused by their digging. Use this method with that knowledge in mind. The old tank that was set up like yours was set up for 3 years and had large foul smelling gas pockets after about 6 months.