My pond pump has a recommended max outlet hose of 1". I am using it with a 1.25 hose so can this damage the pump. I am getting a very healthy flow from both the waterfall and fountain with the larger hose. Also, is it better to run the pump 24 hrs a day or again can it harm the pump to run it timed when needed most i.e. night time. Would appreciate any advice in advance and thanks.
You should have no problem with the slightly oversize hose. I have oversize pipework from my pond pump to a filter/Uv and it runs fine. My pump runs 24hrs 365 days a year no problems. Pumps last about 5 yrs.