My successful reef system "recipe" calls for a deep sand bed (DSB) as 1/2 of the biological filter.  In order to be truly effective, especially in NitrAte reduction, our tanks need a sand bed of about 4 inches for tanks up to 4 feet long and 5-6 inches for 6 foot tanks.  Sand type & grain size is also critical.  Larger substrate like dolomite tends to trap detritus and needs a much greater dept to do the job of smaller aragonite sand.  This article targets those who already have a saltwater tank (fish only or reef) up & running but who want to install a proper deep sand bed (DSB).  Here are the steps to take:

1.  Premix saltwater days in advance to replace any removed during the sanding project.  A little more than the amount you will siphon out to hold your fish & corals during the project.

2.  Shut the system down, siphon out a container (or more if you have lots of fish) of water for your fish to be held in, another for your corals and another container to place your rock in (they won’t need to be submersed – they are fine just for a few hours damp) and another container to hold your old sand in.  Clean pails or plastic totes work well.  If planned well this would be a great time to catch any fish you want to bring to your LFS.  :c)

3.  Remove your corals and rock then your fish.

4.  Remove your existing substrate & discard if a dolomite, shell or other non-sand product.  Install about 2 – 3 inches of Aragamax sugar fine base.  Depending on the size of your tank and what your old substrate is.  If you already have just a sugar size substrate, just add more sugar sized Carib Sea Aragamax on top.  The bottom line is you want to end up with a minimum 3 inch sugar fine base.  To top the sugar fine sand you can use your old substrate if it is the same grain size as Carib Sea Sea Flor or CS AragAlive substrate. If not, just a 1” layer of Sea Flor or Aragalive (live version of Sea Flor).  This is a rule of thumb…not an exact.  Once the sand is all in expect the system will be cloudy until you get it running again.

5.  Add your rock, screwing the base rocks into the sand a few inches for stability. Then finish building your rock structure as best you can with the low to no visibility!  You can readjust things when the tank clears.

6.  Add new premixed water to refill & get your system running again.  I would run Polyfilters to catch the sand dust & possibly detritus unlocked from your old sand bed.  Not only will they help reduce the nutrients released but will help clear the tank faster.  I would also run reef carbon at the same time.

7.  After about an hour or so of the system running again, when the water starts to clear some you can add your fish & corals to the tank.  Don’t worry that it won’t be 100% clear or that you can’t see well enough to place corals exactly where you want them.  Again, you can rearrange things the next day etc. 

This may seem like a big project but usually takes only a couple hours from start to finish & the results will be well worth the effort.