JonasRoman
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I would adress this question to everyone but would be very happy if Randy Holmes Farley have the opportunity to answer also
Thanks in advance my reeffriends.
My own theory is that the old "school" that you hear among aquarist "when you rise the calcium with calcium chloride, the dKH will decline more fast than if you do not" is not quite true.
here is my thoughts and i would be happy if Randy and friends here will confirm or not confirm this:
Ok, first of all some theory: To make calciumcarbonate nonbiologicaly, you have to exceed the saturation state 1.0 in a solution with only just these ions. The equilibrium is with a saturated solution of Ca and CO3, as we know:
(Ca x CO3)Ks=1
Every more added Ca or CO3 ions will immediately make up a CaCO3, to obtain the equilibrium. Ok. BUT: In NSW we have Mg, and some more ions, and maybe som organics, that prevent some precipitation up to at least a saturation index ((CaxCO3)Ks) of 3.0 for calcit and maybe 5.0 for aragonite. This is what i have been learned by studying these things. Please correct me if i am wrong. To this i will add one more issue: Many aquarists think that "only dKH decrease, but not Ca". This if of course never true as it always takes one CO3 to one Ca to form CaCO3, thus, for every 1dKH which decline due to kalciumcarbonate formation it is consumed 7 ppm Ca. BUT, as the resolution of our Calciumtest-kits is less than a dKH test, the aquarist will not easily detect the concomitant decrease in Ca, but of course it is there. And the second thing is that Ca is far mor abundant than dKH, so dKH will reach the "bottom" faster of that reason, and therefore it is not so crucial to obtain an exact Calciumlevel, but of course more crucial to obtain a relative exact dKH level.
Now to my real subject: My theory is that it is not so likely, that you with a single rise in Ca with calcium chloride (within at least values up to maybe 500 ppm,) will get an increase in the calcification and thus velocity of dKH decline. If you for instance have 8dKH in KH, and 420 i calcium. Let us for instance say that you in this case rise the Calcium with calcium chloride to 480. In many aquarists opinion this will press the dKH down. I think that it will not press it down more than if you had 420 in calcium. Because: If you rise the calcium from 420 to 480(quite much) you will only rise the saturationindex (caxco3/ks)with 14%...thus rising the saturation index from around 3.0 to 3.4! Does this really causes an increase in precipitation? i think that the extra calcium ions you added is still in solution(almost), and you have almost the same velocity rate of kalciumcarbonateformation as before adding the calciumchloride.
It is completely different if you do the same and rise dKH of course, as this will increase saturation index much more. I we for example rise the dKH from 7 to 11 dKH we will rise the saturation index with 57% to 4.7. This will cause some precipitation of the added carbonates i think. And of course rising pH which is logarithmic, etc....but rising Ca...i think you have to rise calcium to around maybe 550-600 ppm before you will sea any increase in depressingrate of dKH due to accelerated calcification.
This is congruent with the fact that there is no study as far as i know which have shown that rising calcium(within normal limits) will accelerate coral growth, but there is plenty which has shown that rising dKH will accelerate grown/calcification rate.
well...response and thoughts?
Regards
Jonas Roman
Thanks in advance my reeffriends.My own theory is that the old "school" that you hear among aquarist "when you rise the calcium with calcium chloride, the dKH will decline more fast than if you do not" is not quite true.
here is my thoughts and i would be happy if Randy and friends here will confirm or not confirm this:
Ok, first of all some theory: To make calciumcarbonate nonbiologicaly, you have to exceed the saturation state 1.0 in a solution with only just these ions. The equilibrium is with a saturated solution of Ca and CO3, as we know:
(Ca x CO3)Ks=1
Every more added Ca or CO3 ions will immediately make up a CaCO3, to obtain the equilibrium. Ok. BUT: In NSW we have Mg, and some more ions, and maybe som organics, that prevent some precipitation up to at least a saturation index ((CaxCO3)Ks) of 3.0 for calcit and maybe 5.0 for aragonite. This is what i have been learned by studying these things. Please correct me if i am wrong. To this i will add one more issue: Many aquarists think that "only dKH decrease, but not Ca". This if of course never true as it always takes one CO3 to one Ca to form CaCO3, thus, for every 1dKH which decline due to kalciumcarbonate formation it is consumed 7 ppm Ca. BUT, as the resolution of our Calciumtest-kits is less than a dKH test, the aquarist will not easily detect the concomitant decrease in Ca, but of course it is there. And the second thing is that Ca is far mor abundant than dKH, so dKH will reach the "bottom" faster of that reason, and therefore it is not so crucial to obtain an exact Calciumlevel, but of course more crucial to obtain a relative exact dKH level.
Now to my real subject: My theory is that it is not so likely, that you with a single rise in Ca with calcium chloride (within at least values up to maybe 500 ppm,) will get an increase in the calcification and thus velocity of dKH decline. If you for instance have 8dKH in KH, and 420 i calcium. Let us for instance say that you in this case rise the Calcium with calcium chloride to 480. In many aquarists opinion this will press the dKH down. I think that it will not press it down more than if you had 420 in calcium. Because: If you rise the calcium from 420 to 480(quite much) you will only rise the saturationindex (caxco3/ks)with 14%...thus rising the saturation index from around 3.0 to 3.4! Does this really causes an increase in precipitation? i think that the extra calcium ions you added is still in solution(almost), and you have almost the same velocity rate of kalciumcarbonateformation as before adding the calciumchloride.
It is completely different if you do the same and rise dKH of course, as this will increase saturation index much more. I we for example rise the dKH from 7 to 11 dKH we will rise the saturation index with 57% to 4.7. This will cause some precipitation of the added carbonates i think. And of course rising pH which is logarithmic, etc....but rising Ca...i think you have to rise calcium to around maybe 550-600 ppm before you will sea any increase in depressingrate of dKH due to accelerated calcification.
This is congruent with the fact that there is no study as far as i know which have shown that rising calcium(within normal limits) will accelerate coral growth, but there is plenty which has shown that rising dKH will accelerate grown/calcification rate.
well...response and thoughts?
Regards
Jonas Roman
