Yeah, I’m not going 4-7 times the cost. I saw the higher prices but hoped I was missing something. I’m building out in the property in 1-2 years so will just need to be patient. If there are any smaller incremental and inexpensive things to do that help with aeration I’d be interested.
You could look into doing what I did for my fridge in my camp trailer (and what I may do for my pond pump, once I get one). I used two 100ah deep cycle 12v AGM batteries and a 2,000 watt AIMS inverter/charger. I hooked up two 100watt solar panels to a 30a solar charge controller, which were enough to charge the batteries from 50% back to 100%, in about 8 hours. I could run the fridge on the batteries for about 3 days, before they drained to 50%. Therefore, the panels could keep the fridge running throughout the day, and top off the batteries. Then the system just used the batteries to run the inverter and power the fridge through the night. If I had shore power, I could also plug the inverter into that, and it acted as a much quicker battery charger, while passing power through to the fridge itself, essentially taking the batteries out of the loop.
You could do the same with a pond pump. Just calculate how much solar power you need to run the pump and charge your battery bank, then I would work in a 3X factor, in case you have a few cloudy days in a row. You could also match the size of your inverter to the power needs of your pump.
Inverter/charger I used -
https://smile.amazon.com/gp/product/B01E3V66ZE/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
