Depth of Substrate

[mukundam123]

Hi, I've recently converted from sand to gravel, and have noticed that there are 2 layers of sand: a bottom (darker) and a top (light). I've got a big 'wall' of rocks in the centre of the 4' (55 g) going almost the whole length of tank, but because i thoguht it would be difficult to clean, i've kept the depth of sand under the rocks to about 1/4 inch (well i tried but the sand moves throughout). However, around the side of the rock pile i've got a depth of almost 2 inches! This is where the 2 layers can be seen. I'm guessing this is WAY too much. Anyone got any advice on how much sand I should keep? I'm thinking of putting cichlids in the tank soon (not sure which though).

Thanks

 

[FSM]

So some of the sand is actually darker? Or just looks darker, because less light gets to it? You should have about 1 inch of sand or less. Try stirring it around with your hand (you might want to turn the filters off) and see if there is tons of stuff in it.

 

[japes]

You'll get a lighting effect like that as the light fails to penetrate more than 1cm or so into the sand.

2" is probably a little too much, take all of your rocks out and smooth the sand around and then replace them. I've got about 1 1/4" in my deepest parts but I'm keeping Geophagus so they like sand to sift through.

 

[mukundam123]

So some of the sand is actually darker? Or just looks darker, because less light gets to it? You should have about 1 inch of sand or less. Try stirring it around with your hand (you might want to turn the filters off) and see if there is tons of stuff in it.

Well before i put the rock pile in, I had a piece of Mopani drift wood. When I went to move it, I found that there was a really bad smell coming from the wood, and the sand which it had 'sat' on (this sand was balck so I removed it). I don't think it's happened again, since it's only been a week since I put the rocks in. I'll cut down on the sand i think.

If I put more sand under the rocks, will the sand not become 'dirty', since to clean under them would mean having to move the whole rock pile....????
Also, would a rock pile offer many hiding places for cichlids etc, or would I be better off creating some proper hideouts build into the edge of the rockpile? (not sure how to though....).

Cheers