substrate

[Zachariah]

I am going to set up a new invert marine tank (4foot) i have always u/g filters. I am thinking about not doing it this time.
How deep should the substrate be??
I use a internal juwel filter and and outside power filter for biological needs. I will only be stocking soft corals and mushrooms.
Any advice will help

[ATJ]

Zachariah,

There are many varied opinions on the use of sand beds. Some people advocate bare bottom tanks, others recommend deep sand beds (4" and deeper) while other prefer a shallow sand bed for purely aesthetic reasons. In fact, the discussion about the various methods can get quite heated.

I recommend you read up on the various methods and decide which one will work best for you. If you do a search within Reef Discussion on "DSB", "deep sand bed", "BB" or "bare bottom", you will find a lot of discussions.

Personally, I like the look of a deep sand bed and really enjoy all the organisms living in and on the sand bed. The sand bed has to be seeded with appropriate organisms and new organisms need to be added regularly. If you don't think you can keep up with this, you might be better off with a bare bottom tank which is much easier to keep clean. The sand bed needs to be at least 4" deep and should be composed of find sand with an average grain size of around 0.125 mm.

I also strongly recommend you look into live rock as your primary biological filtration (or at least supplemental if you have a deep sand bed) rather than internal or external powerfilters. The live rock serves as substrate for the corals you will be adding and at the same time can host the necessary bacteria. All you need is good circulation.