Crushed Coral is the same as Oolite?

[aiaman]

When I got my tank a few years ago I put in Oolite for the sand-bed.
Recently, I had seen a few posts saying that crushed coral is bad and fine sand is the right thing to use. Well what I have is Oolite and it is not fine sand like table salt but looks similar to crushed coral pieces.
I am wondering if it is the size thats bad or the actual item.
Also should I replace with a very fine sand or place new sand ontop of the Oolite?
What do you suggest?
My tank is not reef-ready and I use an Eheim canister filter if that matters.
I know I need a deeper bed to have some different animals, that is why I am asking.

 

[LunaReef]

As I understand it, the crushed coral and similar substrates can trap a lot of particulate (detrius, food, etc.) and cause nitrate pockets. Are you testing for nitrates? Do you vacuum the substrate when you do water changes? I'm not sure if there are other concerns...

If you are considering changing it, I would not put it on top. You will still trap stuff in there by doing that. I would ditch the whole thing and start fresh. Just my opinion, of course.

If you have issues getting your nitrates to zero, the substrate could be the problem but I have heard canister filters can cause this also.

 

[JohnK]

It's an issue of particle size. Big chunks make for room for detritis to settle in and rot. Small particles leave a lot less room and are less inviting for crap to settle (but not immune, fine sand beds can accumulate crap too, just not as easily).

 

[aiaman]

ok, I can agree with the particle size being an issue.
and yes, cannister fiolters do cause nitrogen spikes but all I use are filter pads with no substrate.
my last readings were pretty good considering.

So, how do I remove the substrate I have now?
I don't want to remove all the rock as animals have crossed over the connecting rocks and that would disturb them.

Also what would I replace the substrate with, what is the current favorite and to what depth?

 

[stingythingy45]

Why would you remove it?That's a disaster waiting to happen.imo
Oolite and crushed coral are 2 completely different things.You can see shells and stuff in crushed coral.
Crushed coral is basically coral crushed by storms or most likely mechanical methods.
Ooolite= parrat fish poop.Small sandy particles of calcium carb.
Really fine sand just blows around and causes issues anyways.

 

[Greg Hiller]

The stuff that ESV used to sell was called Oolitic sand. I believe that this forms naturally in some parts of the ocean by precipitation of calcium carbonate directly from the water column. If you look at it with a bit of magnification you will see that it is very tiny nearly spherical or oblong shaped particles. I agree that fine sand is generally better than coarse stuff for the reasons that others have mentioned above. However, I've slowly come to believe that long term fine sand beds really do trap a lot of nutrients. I like the look of sand in a tank. I don't see anything wrong with siphoning out sand and replacing parts of it once in a while (I do it myself). What you don't want to do is in the process stir a lot of things up and make the water cloudy. Best to change out small portions of the bed at a time, and when adding sand back to a tank turn off all flow and add it in a small cup that you unload when it is inverted on the bottom of the tank. In a healthy tank this has never been an issue for me.

 

[aiaman]

the sand particle size I currently have reminds me of that coarse sea salt you use for cooking.
All particle size will trap things but I was more concerned with the "crushed coral" issue.
Also I had some problem with a fan worm that maybe the bed is not deep enough or maybe too coarse.
So I thought to slowly change out the sand to something finer.
I have to make the bed deeper anyway so would I be better off to replace or top off?

 

[Greg Hiller]

>be better off to replace or top off? <

Don't think it makes that much difference, however, if you don't like the coarse nature of what you already have you should be aware that if you add finer sand on top now, over time the coarse material will sift to the top surface.

 

[aiaman]

Looks like I need a vacuum for removal & a 1" PVC to aid with replacement and more hands
Thx

 

[Greg Hiller]

All you need is a large diameter piece of tubing from Home Depot and start a siphon (might need someone to help start and stop said siphon becuase it is going to be FAST). Pull out as much as you can get out with a 5 gallon water change (siphon right down to the glass), add sand back for that you removed, then wait a week and do some more.