ordered a bunch of express/priority boxes from USPS. Is it safe to ship priority?
1. fast livestock for 2 daysPriority Works fine most of the time express is best
2. use 1 kordon breatherYes; double bag with another kordon? No
3. styrofoam/ heat pack as necessaryRemember heat packs use up O2 so make sure you are not using the styrofoam cooler with the lids that are fairly air tight
Kordon bags should be completely filled withwater, no air for best results
1. You can fast them, yes, just make sure they're healthy. Priority will typically be fine if properly packaged and the fish/shrimp are healthy
2. 1 bag. Kordon breather bags work off O2 and CO2 transfers. If you double bag, you make that transfer harder. Leave no air in the breather bag, as stated above.
3. Typically will want to insulate the box with styro. Only use heat packs when needed (<60F probably). And make sure if you do use it, you have an open O2 source and that the heat pack is properly secured and will never come into contact with the inhabitants. It will cook them. I lost 3 Tangerine Tigers from a insecure heat pack that fell on them. It being summer, I doubt you'll need a heat pack.
Some people like to add a drop or two of Prime to neutralize the baddies during shipment.
If you end up having questions or concerns as you go through the packaging stage, definitely come to the forum and post pictures or ask your questions. May even be a good idea to go through a trial run of everything - without livestock, of course - just to make sure you feel comfortable with everything.