It depends on the ammonium concentration as well as the temp of the solution, amount of surface area for gas/solution ion exchange as well as what volume of water your looking at. Obviously greater volume = better or lower concentration of ammonia. One last thing most reefers don't take into account when looking at the cycle of a fish tank is the pH level as well as the dKH or "hardness" or "alkalinity" basically the carbonate concentration which plays a large role in leaving room for free ammonia (NH3) commonly in our fishtanks as NH3OH or the ionized form (NH4+) ammonium.
The pH will give a good indication of how much (ksp value) of free ammonia is available in solution and how much is ionized as NH4+. The free kind is the kind that kills fish. Without getting too deep in ksp or the solubility of a ion in a specific volume of water there are easy ways to combat this all together. But just to be a science guy here is a chart to show total ammonia vs ionized.
% Percent of ammonia from 'total ammonia'
Temp C/F pH 6.5 pH 7.0 pH 7.5 pH 7.7 pH 8.0 pH 8.5
20C (68F) 0.125 0.395 1.239 1.95 3.81 11.15
25C (77F) 0.179 0.565 1.766 2.77 5.380 15.242
28C (82F) 0.221 0.696 2.170 3.396 6.55 18.156
30C (86F) 0.253 0.798 2.482 3.78 7.450 20.292
So you can see the dramatic difference in changing pH very toxicity levels of ammonia in the tank....how this relates to shipping, WHELP lets go there..
Lets say you have a volume of 100ml or .1 Liters of tank water. It sits at a temperature of 77 F in your fish tank. Depending on your starting pH and what temperature on average its shipped at the ammonia levels can change given a small volume of solution for the free ammonia to be in at first glace. Now here comes to kicker, im sure this has been talked about in some thread somewhere but ill go into it.
As the coral is shipped in its now air tight bag, assuming we have a good normal temp not falling below 72F and above 80F the coral should remain healthy, but naturally the bag will increase in free ammonia concentration over time. However the carbon dioxide build up, if the bag has room for a volume of air, will force the pH down (more acidic) meaning it will bind free ammonia and keep the coral relatively happy until.........you guessed it you open the bag.
Once you open the bag the aeration that occurs allows for the immediate release of the carbon dioxide from not only the volume of air above the coral (now the entire volume of your house / shop once opened) but it allows for a significant amount of gas to escape from solution, increasing the pH exponentially. This is what allows now for the free ammonia to be released into solution and potentially hurt frags of coral because the pH change (remember folks back from chem in high school 1 pH = 10x difference in H+ concentration
) which even at a level of .5 +/- pH is DRASTIC in my opinion especially to sps corals.
Now for my personal opinion, not based on any experimentation, or trial and error sessions
Get a vial or bottle of some sort that will not leech any harmful things into the water over the course of its hopefully 24 Hr or so trip put the coral fra and the bottle in the water and fill the bottle with the frag in it, then screw the cap on under water, this allows for no gas exchange in the vial itself. Unless undergoing some serious pressure changes it should stay gas free until arriving at the address provided. Take the vial out of the box, place it in your sump to acclimate to temp, then get a container full of fresh tank water and open the vial underwater. This should prevent any sort of drastic ammonia or pH change all together. Again this isn't tested, i'm just throwing it out there. I actually plan to send a few of them this way to you pete
