An Introduction to Substrate Choices - - The Questions Unanswered

[Desert Aquarium]

Ok, so the article is great for describing the substrate design choices, being BB, TSB or DSB, but it doesn't cover actual "Substrate Choices" pertaining to the material used.

I have never seen/heard discussion about Crushed Coral causing problems. Here, it seems frowned upon.

Currently, I have a mixture of Crushed Shell (Puke-a) and a a small about of some "others" mixed in. New to Marine, I thought, "oh Shells, that'll be pretty!" and a year into it I hated it. I went down and got some smaller stuff, a little finer, and mixed it in. "That's better!" I thought to myself.

Another 2 years down the road, I'm hating it again, and decided to go DSB using #0 crushed coral. I went, bought 2lbs or so thinking I'd do 1/2 at a time and nearly killed everything in my tank, losing all the filtration and biological "stuff" that was living in my existing substrate.

This weekend, I am picking up another fair amount of fine SAND to use for a substrate. Do I add it on top? Should I mix it in? Or do I move my fish and LR to somewhere else and replace the other substrate all together?

Right now, I've got a TSB about 2" give or take. I figure an inch of sand on top couldn't hurt, and would infact help to Gobies etc. later, as the Pods move in.

Ideas, opinions, suggestions?

Thanks!

--Phillip

 

[EdKruzel]

In time the finer stuff will work toward the bottom. You can remove part of the larger diameter stuff or leave it.

For a DSB you want primarily very fine sand. An easy way to add it to an existing system is with a friend and the use of larger diameter plastic hose and a funnel.

Turn off all the pumps/filters and hold the hose and funnel.
Have the second person pour the sand down the funnel while you direct the hose and evenly distribute the new layer.

Should the sand become stuck in the hose, have the second person pour some tank water through it.

Give it 30mins or so to settle and then turn the pumps back on; you'll get some cloudiness for a couple of days, but marine animals are used to much worse when storms hit the sea.

Ed

 

[Desert Aquarium]

Thank you! That's exactly what I needed to know!

What about crushed coral? Why does it cause problems with water quality?

 

[bertoni]

It just acts as a detritus trap, collecting stuff that rots and can lead to higher nitrate levels. Other than that, it works well enough and some people have no problems with it.

 

[Desert Aquarium]

More-so than sand?

 

[EdKruzel]

With larger grains the bigger food and other detritus items get trapped under the substrate.
With smaller grains (teeming with life, pods and worms) the food stays above the substrate to be broken down by larger inverts and fauna. That waste is then utilized as food for the sand bed fauna which breaks it down even more and it becomes food for the anaerobic zones.

Simple terms, detritus is more efficiently handled instead of trapped.

Ed

 

[Desert Aquarium]

Ok, please forgive my ignorance, but I would like to verify so that I know I'm following properly-

Corse substrate is bad because it becomes a Nitrate factory.
Sand is good because nutrients stay on the surface where easily accessed.

If I'm right, then I still don't understand how a #0 crushed coral (similar to sugar) is worse than sand (similar to sugar).

I could TOTALLY be missing the point if the term "Crushed Coral" when used is typically describing a more corse crush.

Sorry!

 

[bertoni]

Usually, crushed coral products are fairly coarse. If you can find one in the 0.2mm or so size range, maybe higher, it should be fine.

 

[Desert Aquarium]

Roger that.

All my confusion stemmed from the generic referance to "Crushed Coral" as opposed to "Corse Substrate" and in all actuallity, it's all about the grain size.

Thank you for shedding the MH.