Re: Sand Substrates - an alternate view

>I have been experimenting with sand, sand-peat, and various sand-peat-gravel 
>mixes for about a year, in tanks ranging from 10G to 55G. 

I have been using sand as long as I have been growing aquarium plants.
on six years now.

>In the Western US, it has become nearly impossible to get decent aquarium 
>gravel. Most of what is available is "Lapis Lustre" by RMC Lonestar. It is 
>very pretty, but so loaded with sea shells that it will destroy any 
>soft-water tank in no time. The pH heads up toward 8 rapidly. I have been 
>trying to use silica sand-blasting sand, which normally is widely available 
>in only 30 mesh (quite fine).

When you use sand, espically fine sand you do not have to have as deep
a substrate.  I use between one and two inches.

>My tentative conclusion is that it compacts too much to be a useful 
>substrate, and my various attempts to adapt commercial UGF plates and 
>custom-designed UGFs have to all be rated as failures. They kind-of worked, 
>but not well enough to recommend them to a friend.

An UGF and sand is NOT a good idea.  First it is difficult to keep the
sand out of
the filter and the usual depth of substrate needed for a UGF is much
to much for

>Vacuuming works OK if you use a larger-mouth vacuum tube and smaller hose to 
>avoid sucking the sand out. A layer of coarser gravel over the sand works, 
>too, but you need to resist the urge to plunge the vacuum too deep.

Most of the crud stays on top of sand so you do not have to vacume to

>I am facing the most unpleasant task of tearing down a heavily-planted 55G 
>this weekend, to replace the mixed substrate that has been in there for 
>almost a year. It is hard as a rock in places, and highly anaerobic looking. 

The only times I have had this type of problem is when I used peat
in the substrate.  Usually there are no anaerobic sections or they are

>This unpleasant task is what prompts me to take your question as an 
>opportunity to advise people that sand can be a real problem. My apology to 
>the folks on the plant mailing list for reporting it here first. I had been 
>planning to post this there, but it is hard to admit a solid string of 
>failures, so I never seem to get a "round tuit."

Any substrate can cause problems.  One point.  Did you have an
snails in the tank?  They constantly dig in the substrate performing
the same
functions as earthworms.  I would not think of a tank without these

>Bottom line: Don't use fine sand unless you have a profound reason to do it.

Beg to differ here.  I would not use anything else though I have been 
experimenting with adding some earthworm castings to the bottom inch
of sand when I use a 'deep' substrate of two inches.

Ed Tomlinson (tomlins at cam_org)
Montreal, Canada

Home of pppdial: http://www.cam.org/~tomlins/pppdial.html