Is crushed coral "gravel"?

[cashay]

Can it be used instead of gravel? or is this just something you add to gravel to help maintain water parameters? I am going to move my tetra's to a 14 gallon at least that is what I think it is.. says has 14 glass aquarium I don't know, I have never heard of a 14 gallon..but I am getting this today and will be setting it up for cycling and i was just curious about coral, I know some one has mentioned it before but trying to go back and find the forum, is time consuming.
And am I correct in saying that a OTTO will be ok to add in with Tetra's to help with my vacuuming?

[Carl]

Depnding on your terminology, I would say yes.

Crushed Coral is not rock but coral skelton, sea shells in a uniform gravel or substrate and is most commonly used in #3 or #5 grade.

Use of this with Tetras as your primary substrate can cause problems with pH/KH, however the use of Crushed coral in a nylon filter bag to aid in KH/pH MAY help, however I have found that often Crushed Coral is low in carbonates and bicarbonates which is what you need to bring "up" pH and KH in either salt or freshwater and even in saltwater aquariums I have found over the years that the use of crush coral and regular water changes in often inadequate to maintain alkalinity/pH.

Aragonite tends to be better at maintaining KH/pH due to more surface area for disolving cabonates/bicarbonates and higher levels of these elements as well.

See this article for some pictures in the sand/substrate section;
Marine Aquarium Basics

Carl

[cashay]

Great Thanks again!

[eve]

for me, yes it's absolutely gravel
especially if you're an african cichlid keeper, it's very helpful, as it will keep your pH where you want it

it's also used as a pH booster if you need it in the filter as mentioned

[Carl]

Oct 31, 2008 20:42:54 GMT -5 eve said:

for me, yes it's absolutely gravel
especially if you're an african cichlid keeper, it's very helpful, as it will keep your pH where you want it

it's also used as a pH booster if you need it in the filter as mentioned

Sorry to jump on when you just got back Eve

But I have disagree with this statement.
Unfortunately many years back I too thought this, but after others pointed out the chemical make up of crushed coral and my many tests since then I found this to be another aquatic urban myth.

Crushed coral is primarly coral skeletons comprised of the mineral Calcium Carbonate with little available bicarbonates NECESSARY for increasing KH.
Crushed coral can maintain pH/KH in a well maintained low bio load African Cichlid aquarium, but it is a poor choice to raise KH.
It is however a reasonable choice for other minerals important to GH (although even here CC does not respond to rapid chemistry changes as well as Wonder Shells which I think are a better choice here).

This article deals with this subject in the KH section (I just finished an update too which I will post when I have time to proof read it)
CALCIUM, ELECTROLYTES, AND MAGNESIUM IN AQUARIUMS; How to maintain a Proper KH & PH, why calcium and electrolytes are important

Carl

[eve]

well i never said anything about KH or GH, as i have no clue about either of them

[goldenpuon]

I'm not sure if this is what you are asking but Kh is alkilinity and Gh is Hardness. I'd imagine crushed coral affects either or both of them if it affects PH..

[Carl]

Nov 3, 2008 1:32:16 GMT -5 eve said:

well i never said anything about KH or GH, as i have no clue about either of them

KH is the buffer that controls pH, without any KH (Carbonate hardness), your pH would plunge from the carbonic, nitric acids produced during normal bio filtrations.


Carl