I figured at the time that two diffusers was better than none, and that’s what I had the spare cash for, pumps, rebuild kits, diffusers, putting the electric cable in and weighted air hoses. Now I want to move onto stage two, again have some spare cash to do it now.

Will look into depths and more precise size this coming week and as I said I’ve got two pond guys coming out next week. Then armed with all the pertinent depths and test numbers will get a plan sorted out. A good supplier of weighted air line was my main concern and some reasonable straight forward advice.

The larger 3/4HP takes a bit more electricity to run and only have the two diffusers out there anyway. Although I do like the look of this type of DIY solar setup-
https://m.youtube.com/watch?v=UyTTbt-dpRQ
Or at least is a good starting point for me to figure my own out.