Ok guys, so i don't know what Iam doing ! This weekend i let kids fish the pond, 14 gills I'n top water flies, found 4 dead today. Stress i guess. Caught 16 perch and 8 brook trout 4 ft down over 8 ft on worms . All fish CPR ... So surface temp is 63 and 45-46 at 18ft hole. I got power at pond today. Hp 80 with air rock , dropped it 18 ft hole..... Nothing no bubbles at top. I moved it over to 8 ft depth and looked great. So my question is will i be doing harm if i put it I'n 18 ft hole with No plum coming to the top of water. I will be putting I'n rainbows soon, i hope. Should i put stone I'n 8 ft to get correct plum? I won't be aerating the depths like i should be I'n the summer. Should i purchase i different defuser that will work at 18 ft depth ? Then save stone for winter use? Will aeration help with the alge bloom i have going on right now ? I need help.