I am about to start filling the 1/2 acre pond we have just rehab. The pond is an offline pond, which is fed off a stream with a 4" feed pipe with a pretty steady flow. Will the oxygen level be sufficient by just running the feed onto the pond. I have plenty of rock and have piled rock in front of fill pipe to prevent erosion. It is my understanding that with the water falling over the rock will help to aerate. Then I hear from one of my neighbors I would be better off to extend fill pipe out over the water and let it splash into the pond. Help a rookie out, could use some advice.

If diffused aeration is an option, I would go that route. I'm also in NC, with a .5 acre farm pond. Based on my observations, the aeration has really helped the pond get healthy again.

If you plan to stock it anywhere near carrying capacity, it's excellent insurance. Stocked fish are not cheap.

I can not help to think that the water you are getting from the stream has good dissolved oxygen unless it goes stagnant, but then I would not consider it a "stream". It would be more of a wet weather creek.

Anyhow, if your steam is flowing all the time then the oxygen content will be better than your pond water and would be helping the pond out. I would also think that cascading the stream water over rocks before it enters the pond would be better than just dumping it into water from above the surface. Now, one could ague this if the flow from the 4" pipe would be sufficient enough to turn the pond over more than once a day. This flow would act more like a aeration system that does most of it's work by exposing water from the lower levels of the water column to the air to water interface at the surface. I doubt that a "pretty steady flow" from the 4" pipe would perform the task of turning the pond over once a day. So, my deduction would be that cascading the inflow over some rocks would be best, although not really necessary if the stream water is already high in 02.

An aeration system can only help if properly sized as you would get the benefits of having D02 throughout the water column, but would not be necessary especially if you are not going to push the carrying capacity of the pond and your stream water is of good quality.

Just remember that what ever comes down the stream goes into the pond. Including what ever is up stream like other fish species, algae , garbage who knows what. What if somebody off the property dumps waste oil in it to get rid of it. You never know. Just a risk to be aware of. Good luck

Assuming the head of your fill pipe is some distance downstream from the actual spring, the natural flow should adequately oxygenate the water prior to it entering the pond. Then flowing it again over rocks will further increase that O2 level. If you intend to allow the pond to overflow from continuous influx of fresh water, the cooler water will naturally sink as the warmer water rises as it moves to the spillway. I don't think you would have to do anything else. Keep in mind thats all depending on the depth of your pond. With enough depth (greater than 10 feet), you may have to introduce some kind of circulation to prevent stratification. Just my opinion.

A good screen filter to prevent unwanted intruders from entering thru the pipe would be a must, but that doesn't combat any contaminant that might get introduced. You'll have to keep the filter clear to ensure a good flow.

If you own the spring, then the contamination aspect is greatly reduced, but you need to put a little distance between the spring and the pipe head so your water can flow a little before entering the pipe. The water coming directly out of the ground wont have much oxygen in it. You need that flowing action.

I admit, I assumed the stream was not spring fed or, at least, not spring fed in close proximity of the feed pipe. If the spring is close by, D02 would need to be determined..

Good point Mike!

Lol.... I just went back thru the original post, don't see "spring" anywhere in it!! Don't know where I got that from!!!

My apologies Crusopond. I would never intentionally give you misinformation. Please disregard any reference to springs....unless it is!!

I'm glad you mentioned it Mike because my response ignored that there might be a spring involved. Goes to show you that "it depends"!