does crushed coral nsec to be changed? how long os the effectivity of crushed coral in keeping the ph stable?
does crushed coral need to be changed?
- Thread starter batang_mcdo
- Start date
There are a number of factors which will alter how quickly the effectiveness of crushed coral is depleted. But once the pH begins to drop, it's time to change it. Don't wait, because it is not a gradual failure. The pH will drop farther and farther very soon.
Coral buffers the water by eroding... so once it's gone, it doesn't work anymore...
Coral does not buffer water by leaching something into the water column that can become depleted... it is the coral itself that erodes and alters the PH...
Coral does not buffer water by leaching something into the water column that can become depleted... it is the coral itself that erodes and alters the PH...
thanks 
So as long as the coral is still there, it should still work? because i've read some where that crushed coral also needs to be changed. i have some crushed coral in my tank so far ph is still at 7.5 which i where i would like it to stay, but not sure if the crushed coral needs to be changed as i don't want to be surprised by a ph crash.
So as long as the coral is still there, it should still work? because i've read some where that crushed coral also needs to be changed. i have some crushed coral in my tank so far ph is still at 7.5 which i where i would like it to stay, but not sure if the crushed coral needs to be changed as i don't want to be surprised by a ph crash.
Yes, but some parts of the coral erode faster than others. The calcium might be largely gone from a piece while other minerals maintain a fragile skeleton. The other minerals should dissolve, too, but some peoples' tap water might be saturated with, say magnesium, and fail to corrode that mineral while still making good use of the calcium.
Just keep an eye on it. When it begins to drop, add some fresh coral to the mix or replace it if it is "skeletonized" and not buffering the way it should.
Just keep an eye on it. When it begins to drop, add some fresh coral to the mix or replace it if it is "skeletonized" and not buffering the way it should.
I was under the impression that crushed coral substrates will remain effective for far longer than any aquarium setup will last.
the calcium carbonate ions (the main one that does the buffering, but as mentioned there are others) that are being released out of the coral into the water will keeping coming out for years and years.
this is because an equilibrium situation does not exist with the coral/water because of the fact that water changes are constantly changing it.
if you never changed your water then yes, equilibrium could be reached where no more ions would be released.
but since we change our water, after each water change, it changes the equilbrium and more calcium carbonate would be released..
I have never heard of crushed coral substrates needing to be changed because they no longer buffer..
the calcium carbonate ions (the main one that does the buffering, but as mentioned there are others) that are being released out of the coral into the water will keeping coming out for years and years.
this is because an equilibrium situation does not exist with the coral/water because of the fact that water changes are constantly changing it.
if you never changed your water then yes, equilibrium could be reached where no more ions would be released.
but since we change our water, after each water change, it changes the equilbrium and more calcium carbonate would be released..
I have never heard of crushed coral substrates needing to be changed because they no longer buffer..
from what I understand, coral based substrates do slowly dissolve (the calcium carbonate dissociates) but the sort of timespan in order for substrate to lose its effectiveness as buffer (ie all the carbonates have been dissociated out as it reacts with the water) is over a very very long period of time.
I was under the impression that crushed coral substrates will remain effective for far longer than any aquarium setup will last.
-----------Well, that's a nice thought, but unless every drop of new water entering the tank during water changes is as hard as the existing tank water, the coral will react to buffer and become corroded with time.
the calcium carbonate ions (the main one that does the buffering, but as mentioned there are others) that are being released out of the coral into the water will keeping coming out for years and years.
-----------Possibly for years and years, but it does depend on the hardness of the fresh water added every water change.
this is because an equilibrium situation does not exist with the coral/water because of the fact that water changes are constantly changing it.
-----------Right.
if you never changed your water then yes, equilibrium could be reached where no more ions would be released.
-----------Yep.
but since we change our water, after each water change, it changes the equilbrium and more calcium carbonate would be released..
-----------There you go.
I have never heard of crushed coral substrates needing to be changed because they no longer buffer..
-----------Didn't you just say more calcium carbonate is released every water change? It had to come from somewhere, didn't it?
-----------Well, that's a nice thought, but unless every drop of new water entering the tank during water changes is as hard as the existing tank water, the coral will react to buffer and become corroded with time.
the calcium carbonate ions (the main one that does the buffering, but as mentioned there are others) that are being released out of the coral into the water will keeping coming out for years and years.
-----------Possibly for years and years, but it does depend on the hardness of the fresh water added every water change.
this is because an equilibrium situation does not exist with the coral/water because of the fact that water changes are constantly changing it.
-----------Right.
if you never changed your water then yes, equilibrium could be reached where no more ions would be released.
-----------Yep.
but since we change our water, after each water change, it changes the equilbrium and more calcium carbonate would be released..
-----------There you go.
I have never heard of crushed coral substrates needing to be changed because they no longer buffer..
-----------Didn't you just say more calcium carbonate is released every water change? It had to come from somewhere, didn't it?
The quantity of crushed coral in the system as well as the ph/kh of the water added at each water change will directly impact the life of the crushed coral...
　
When we use crushed coral as a substrate and thus have around 1 lb of coral per gal of water... the coral will take much much longer to dissolve than if we used an inert substrate and only placed a half a pound of crushed coral in the filter...
　
When we use crushed coral as a substrate and thus have around 1 lb of coral per gal of water... the coral will take much much longer to dissolve than if we used an inert substrate and only placed a half a pound of crushed coral in the filter...