pH is ok (depending on the time of day taken) alkalinity and hardness are good. Do a bunch of research on the proper way to aerate a pond. Running it 30 min a day you could be doing more harm than good.

If you don't have an O2 meter and just doing what you are doing, you could be playing with fire. If you have H2S build up in your pond, running the aeration system for that long is not a good thing. Without knowing how to properly aerate a pond, running bubbles of air in the pond could do more damage than good. There's a lot of misconceptions about aeration and a lot of Facebook Cowboys that are giving out information that don't know a dang thing about it.
Without an O2 meter, being able to take the water temp at the bottom of the pond is almost as good.

There has been a lot of info posted on here about proper aeration. I could re-type it, but it would take me about 45 minutes to re-do it.

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3/4 to 1 1/4 ac pond LMB, SMB, PS, BG, RES, CC, YP, Bardello BG, (RBT & Blue Tilapia - seasonal).