cwolfus
Past President
Hey gang,
In moving to my new tank (which still needs some work) I put some time into documenting the breakdown of my old 55g. I thought this may be of interest since it was designed with a plenum and had been up for over 8 years. Even though I don't think anyone designs with plenums anymore this may be of interest. Enjoy...
Step 1 - The top layer
The top layer of sand was a mix of fine and medium grain aragonite about 2 inches deep. In scooping this out I found many detritus eaters including a variety of worms and snails.
Step 2 - Peel back the window screen separator to reveal second layer
This second layer originally was solely crushed coral substrate. Note the muddiness and the large worms and other life!
Step 3 - Exposing the plenum
Below the second layer was the plenum - some eggcrate wrapped in window screening to facilitate bacterial growth in a low oxygen "nonoxic" environment. Note the interesting orange bacteria growing on this layer.
Step 4 - the bottom
Under the "nonoxic layer" plenum is anything that is small enough to fall through. Check out the nonoxic muck...
Conclusions
This design did trap a lot of detritus in the first two layers where worms and other fauna could break it down. The plenum also seems to encourage bacterial growth to further break down waste. However, I'm not so certain about the the benthic bottom that collected whatever was small enough to fall through. Seems like it kept a lot of waste in the tank.
Cheers!
-Charles
In moving to my new tank (which still needs some work) I put some time into documenting the breakdown of my old 55g. I thought this may be of interest since it was designed with a plenum and had been up for over 8 years. Even though I don't think anyone designs with plenums anymore this may be of interest. Enjoy...
Step 1 - The top layer
The top layer of sand was a mix of fine and medium grain aragonite about 2 inches deep. In scooping this out I found many detritus eaters including a variety of worms and snails.
Step 2 - Peel back the window screen separator to reveal second layer
This second layer originally was solely crushed coral substrate. Note the muddiness and the large worms and other life!
Step 3 - Exposing the plenum
Below the second layer was the plenum - some eggcrate wrapped in window screening to facilitate bacterial growth in a low oxygen "nonoxic" environment. Note the interesting orange bacteria growing on this layer.
Step 4 - the bottom
Under the "nonoxic layer" plenum is anything that is small enough to fall through. Check out the nonoxic muck...
Conclusions
This design did trap a lot of detritus in the first two layers where worms and other fauna could break it down. The plenum also seems to encourage bacterial growth to further break down waste. However, I'm not so certain about the the benthic bottom that collected whatever was small enough to fall through. Seems like it kept a lot of waste in the tank.
Cheers!
-Charles