First, I want to say that all my theories are based on high school chemistry, and I'm in no way considered an expert chemist. This is how I understand this, and what my logical opinion in what happens with the DIY Rock during Kuring.....
__________________________________
My Thoughts, Opinions, and Theories on the DIY Rock Kuring Process
First, there are two parts to Kuring rock. The solution that the rock is being Kured in, and the composition of the rock itself. One, the rock itself, is a constant factor. The water is the variable. We know that the rock itself when placed in the Kuring vat will leach out a chemical and cause the pH to rise to 11-12 and begin to drop as it comes out of the rock. I don't know what this chemical is, but I assume that it is either Carbonate or Calcium based. I'll call it "Chemical X". The process to me is similar to Calcium Hydroxide (AKA Limewater). Now, we have the variables with water. Let's look at some of the things that we know about H20:
1) Pure water is considered the universal solvent. With time, water can dissolve anything.
2) Any solvent has a saturation point. Once the solvent reaches the saturation point, it stops dissolving the solute. Yes, you can do stuff to make a solven super-saturate, but I don't know how in our case.
3) pH determines the strength of the acid/base. In our case, the pH of the solvent increases to make it more base. The higher the number, the more "Chemical X" is in the solution; the higher the concentration Chemical X in the solution, the closer it reaches the Saturation Point; and the closer it gets to the Saturation Point the less of Chemical X can leach out into the solution. Thus slowing the Kuring process down.
4) pH also determines how the solute dissolves. The larger the difference in the pH of the two items, the faster it dissolves. Thus, something like Bleach and Battery Acid will (extremely) quickly form a chemical reaction. But something like Water and Milk will take a long time for the chemical reactions to take place.
With all that being said, I'll then compare Seawater and Pure Water. Seawater has a pH of about 8.3 and also is already filled with other chemicals, so there will be less room for Chemical X to fit in. Thus, it will leach Chemical X slower at first. Eventually, it wouldn't matter if which water the rock is placed in as Chemical X reaches maximum concentrations, the amount that leaches slows down. So, now we have a problem with reducing the amount of Chemical X that is in the solution. Thus, water changes are the best bet. Now the choice of a body of moving water, or manually changing them in vats is a personal choice. It would seem that moving water would have the best, immediate benefit. But there are ways to speed up the dissolving of a solute. There are three common ways of speeding up the process; heat, aggitation, and particle size. We can easily control two of those in a vat, but not in the ocean. In a container, we can add a heater for heat and a powerhead for aggitation. We can't control the particle size of the solute, but the solute dissolves as water penetrates the rock. So, the thicker the rock, the longer it takes for it to Kure.
With all that said, this is my advice to all that do DIY Rock without a body of water:
--Use the purest water with the lowest pH.
--Change the water as often as possible. Changing the water as often as once or twice a day, or even when the pH reaches a predetermined amount (IE change it when it reaches 9.0)
--Add a heater for heat and a powerhead for aggitation
--Keep your rocks small to Kure faster. If you want a larger rock, cement or epoxy them together after Kuring.
***NOTE***
Once again, I could be COMPLETELY WRONG on this. This is why it is my opinion/theory. If I am wrong, please help me correct this. If you know what Chemical X is, please let us all know.
