DSB Plenum

[Doug]

Use a larger grain on the bottom 2 in. I liked something close to the 5mm sized crushed coral or perhaps something similar from Carib Sea. Then another layer of window screen to keep diggers from the bottom layer. Top 2in. or amount your using could be finer. The Carib Sea 2mm aragonite is something I used. Could also mix some of the finer with it.

The larger gravel on the bottom of complete bed, allows better diffusion through to the plenum.

My friends however is all 2mm aragonite. Oh and his tank is now over 10yrs, with it. Many still use the plenum. Perhaps not as popular as once but either is dsb. Shallow and bare are the more popular options now.

There is still a regular plenum column in Aquarium Fish mag. which now contains FAMA