Kent -
Good to hear from you! You still need to send me some pictures of your pond!
As for Salt - Yet another ongoing debate in the watergarden world... Some people like to add salt all the time, some just in the spring and some never add it.
Most people use it as a the first line of defense when their fish start to come down with something. A healthy level of salt in a pond is good, but you dont want it to go too high, or your plants will start to get affected.
I always buy the softener salt at the grocery store when i salt my pond. DO NOT GET TABLE SALT though... that would make the KOI GUMBO that you speak of. Stick to softener salt that comes in the large bags.. and make sure its all salt with no other fillers...
Algae is not a huge fan of salt in higher amounts (just like the other plants in your pond) this may help decrease some algae... however you did say this was a pond tour... many locations on pond tours are known for sometimes draining out their ponds and removing all the algae right before the day of the tour
I guess you really need to first ask yourself why you want to add salt to your pond? Are your fish acting funny in that you may suspect some parasites? Or are you trying to control Algae? If you are trying to control Algae in a pond then there are many other more affective ways of doing it than just using salt treatments.
I usually only salt my pond in Minnesota in the spring after the long winter if i see my fish are acting funny, otherwise i leave it out and so far it has worked pretty well for me.
If you do plan on adding salt regularly, i recommend getting a salinity meter testing kit to make sure you keep the levels in an acceptable range.
I do not have my dosage numbers around me at the moment and i dont want to quote you the wrong treatments so I will add to this post once i get them.
If you have any other follow up questions feel free to shoot away!