New pond to be dug in next couple weeks, clay bottom, 6.5 feet deep in middle, about 50' x 150' in size. Couple things I'm thinking about adding ahead of filling it with water:

1. an aerator in middle (close to deep center hole) that would run all year. I plan on burying the tube and have it pop up next to solar panel and battery mounted on North side of pond.

2. a pump to add a small current around the pond. I would also like this to be DC so I can hook right up to solar and battery. This current will help keep from stagnent.

3. good to know I will have to add some supplemental water via sprinkler in summer. I plan to have that on edge of pond which will also help a little bit with stagnent water.

I plan to add sunfish and bass at some point and when digging is complete will lay a log or two anchored in bottom for structure. If no good DC options for aerator or current pump, I could always use inverter to convert of battery to "normal" plug in power (you just lose some power during that process). Any suggestions if think this will work and type of aerator or pump to use, please let me know. thank you

Welcome aboard!
#1, run when water temp is 55 and above, do NOT run in winter, it will super-cool the water in below freezing events, you want the most 39 deg water in the bottom of the pond. Ice over is a good thing when temps get really cold.
An alternative is move diffuser into 3' water when temp drops below 50-55.
#2, stagnation will occur without aeration if conditions are right, if aerating, you won't have that issue.
#3, if you are supplementing water during summer, run it into pond direct, don't atomize it with a sprinkler. 30-40% will be lost to evaporation. the aerator is keeping your water from becoming anoxic. If for fishing, add all types of structure/habitat, deep, shallow and everything in-between.

Welcome to Pond Boss!!

With a Minnesota winter, I wonder if more depth than 6.5' would be helpful, however, aeration may assist with that if done properly.

For #1, I wont but the aerator in deepest hole, instead over where it's like 4' deep. That way I don't "super-cool" the water in the deepest hole? Any recommendations for this type of aerator? FYI I plan to run DC power from solar.

Thomas pumps seem to do well. I run 3 on 24v solar but I don't use an inverter, I use a charge controller that regulates 24v to load side and I don't have the efficiency loss of an inverter. Highflyer is the guy to talk to on this about solar. For no more demand than I have, the charge controller works great with 2 200w panels in series with 4 12v batts in series parallel.
I can't speak for Brian, but I'm guessing he would suggest a Brat controller for a simple setup.
Membrane diffusers are probably the best quality although I have a matala Hose type (like soaker hose) 9" ring diffuser I clean with 500ppm H2O2 every year and side by side with Matala membrane I don't see much difference until late summer (but that IS the time you need efficient aeration).

For as little of a pond as you are talking about, a single diffuser should be just fine, in fact it might be too much.

For the solar, you need to know how many kWh of energy you need each day. Then if you are going to use Lead acid batteries, multiply the amount you need by 2.5 times.

The 2.5 multiplier is to protect the batteries in winter. Never let your batteries get below 60% SOC in the winter. If they freeze, they are dead. Lead acid batteries will not freeze at 60% SOC until there are negative temps.

So let's say you are using a 50 watt pump 24/7. That is 1.2 kWh of energy used a day. You would like to protect your system for four days without sunlight. That is 4.8kWh. Now multiply that number by 2.5 and you get that you need a 12.5 kWh battery. 500 amp-hours is a lot of battery (12500 watt hours/24 volt battery rounded). Certainly, you can go with a smaller battery and protect for fewer days. You will also need a controller which can turn off the load to protect the batteries.

Does any of this make sense? If so, you are on your way.

Choosing the right charge controller is another matter. Let's get through step one first.

Yep, the sizing of panel and lead-acid battery makes sense. I've had a few panels up this winter powered securing cameras 24/7. My biggest challenge I'm having now is finding a DC powered aerator. Not a lot out there I can find. Any suggestions?

This DC air pump work? https://www.amazon.com/Portable-Aquaculture-Hydroponics-Aquarium-Compressor/dp/B00W6WP62C.

Look for 24 or better yet 48 volt DC pumps.

i would look for a quality pump. Thomas, Gast, etc. I would shy away from cheep stuff, you will be replacing them often when they fail.

saxon11, I use a 24v Thomas, (107CDC20, 24v), they are not cheap but I'm going into year 4. I had a reed valve fail after year 1, then got smart and replaced diaphragm and reeds each winter since. Pump is about 400$ new but worth it. I keep an extra diaphragm repair kit on hand in case but replacing once a year seems to be effective.