DSB or 'Deep Sand Bed' in comparison to other filtration methods such as Under Gravel Filters.

For many years the UGF or 'under gravel filter' has been the mainstay of the marine aquarium industry and not surprisingly it still has its die-hard followers even now.

Without getting into any controversial arguments though, let me just say at this point, that I whole heartedly agree that in some tanks and under certain conditions the UGF in all its guises has and does work, So I'm not arguing as to its effectiveness at general filtration.. For reef keeping though, the UGF does have some drawbacks. Firstly in that 'by definition' a UGF requires a media of decent granular size to allow the easy passage of water through it to keep it healthy and biologically effective. This will usually consist of a grain size no smaller than about 2-3mm in size (typically crushed coral sand or gravel). One of the big drawbacks with this type of grain size is that each grain has an ideally large surface area for the colonisation of problem algae, hence the deep green tinge common in the sand of UGF run systems. The other drawback to large granular size, is that it all too easily allows quite large particulate matter/ detritus to fall between the grains which over time builds up and starts clogging the bed unless the keeper regularly Hoovers the gravel/sand via the use of a gravel vacuum. Effectively the UGF is part biological filter - part mechanical filter.

What is live Sand and how can it be alive?

Well, the sand itself of course is not alive, but there are organisms they are alive that are around the live sand and within the live sand or on top of the live sand, and most these organisms are beneficial and help to maintain a balanced aquarium. So live sand can be very important in maintaining a healthy reef aquarium, but it does have its drawbacks.

There are two important considerations when you're dealing with live sand.

The first consideration is particle size and second is the composition of the sand.

What is live rock? How can rock be alive?

Live rock is rock from the oceans reefs that have living organisms living upon it and within it. Properly cured Live Rock is probably the ideal filtering method for your aquarium.

I highly recommend live rock for any type of saltwater aquarium even if it is a fish only system. Most organisms that live in the live rock are either microorganisms or burrowing organisms such as worms and small snails and stars.

On the outside of the live rock can be anything from sponges and tunicates, anemones in corals and the reason that live rock is such a great filtering mechanism is because of the bacteria that live on the rock and within it. There are just several different types of bacteria.