There are two versions of the balloon rezzer included.

One is just a invisible cube which will rez balloons. The other has a net holding the balloons which turns invisible when balloons are being created.
(The Net version is 20 prims. The cube version is just one prim, for those who wish to keep prims to a minimum.)

The balloon rezzer has various commands you can use to change the settings

In chat use the following commands.....

/88interval - set the time in minutes. Balloons will be rezzed on this interval. (replace with a number value)

/88radius - This sets a radius around the balloon rezzer in meters. If there is no avatar within this radius no balloons will be rezzed. It will only create balloons if an avatar is within the specified area. (replace with a number value)

/88bursts - 8 balloons are rezzed in a burst. This setting you can adjust how many bursts will occur when balloons are rezzed. I recommend about 2 - 5.
(replace with a number value)

/88settings - this command will show you what the above 3 settings are set to.

/88show & /88hide - this only applies to the box version, it will turn the box visible/invisible to help you locate and position it.

* NOTES & ADVICE *

I recommend that you do not set the balloon rezzer to create too many balloons at once. Physical objects can add to lag on the sim while they are in world .
To help reduce problems they are set to Temp On Rez, and to burst and disappear reasonably quickly automatically.

Also make sure that the rezzer has a clear area around it. If it creates balloons that interpenetrate other objects you may experience problems.