Question
Hi, so I have a question about my parents pond pump- if this doesn't make sence I will ask again and send pictures to explain it better.  So its a smaller pond that waterfalls down into a bigger pond. The pump is in the bigger pond and it has a hose on one side that brings water up to the smaller pond, the hose on the other side of the pump has just a short hose that is pouring water out of it back into the bigger pond- there is also another hose that is empty and doesn't do anything beside the hose that goes up to the top pond- that hose and the one that pours out water into the bigger pond have never been connected. So If this makes sence I think I am  either suppose to get an extension hose so that 2 hoses bring up water to the smaller pond for extra movement- or the one that puts water into the bigger pond is just for extra movement into the bigger one??  Thank you!

Answer
More than likely, there used to be another pump hooked up; and it was at some point removed.  The extra hose coming out of the pump is probably, as you said, to introduce some additional circulation into the lower pond.  It could also be used to fine tune the rate which water goes over the fall.  It would be better to use only one hose to deliver water to the top pond.  You can find the maximum allowed flow in a particular diameter tube and if the pump (minus head pressure) does not exceed the tubing's limit, your setup is fine.  Look it up online to see exactly what situation you're in regarding pump size, distance, water flow, etc. then you can make decisions from there.

If I haven't effectively answered your question, feel free to re-ask with pictures.