In a pond max depth of 21 ft. No shad in pond.

http://i1204.photobucket.com/albums/bb410/karson191/A5EE03C4-6AA5-464A-BC27-76DD69AB5DB5_zps9nu0hbft.jpg

Any grass or brush in the pond? Could be a small school of crappie, bass, even catfish. 

Well it don't look like a small school to me. Do minnows school like that. I think they are too tight of a school for bass or something. I may be wrong tho

Too tight for a school of bass?? Just depends on the situation.

 

This is a school of bass:

 

Hmm. Guess I could have fished it. I did a little bit went back over and didn't see it

Do you have any perch in that pond?

No perch. There is catfish, grass carp, brim, crappie, and bass.

I can't see a temperature gauge but when the water is cold fish will often school very tightly.

Yeah I don't have temp. But The water is cold. I'll feel of it with my hands a lot and is guess it's in mid to low 50s.

Lower end units like that often show false objects and readings

Yeah I don't have temp. But The water is cold. I'll feel of it with my hands a lot and is guess it's in mid to low 50s.

 

Buy a thermometer with a probe.