Originally Posted By: Charlie B
Lost 4 20-22" Bass last Thursday, which I am still sick about� Checked things out Friday morning (7/19/13), hoping whatever had happened was over and I noticed 12" Bass and BG were in big groups at the edge of the pond. As the day went on they receded into deeper water.

I had been running a 3 disc bottom diffuser aerator 24/7 since spring that was built based on feedback from this forum last summer; it�s using the economy ECO7 pump.

Since I assumed the issue was lack of DO, I didn't yet have a DO meter. I added a 1/2HP HO Kasco deicer I mounted to 3 t-posts in the pond to add surface aeration. The deicer created a plume of water 16� high and about 30� wide which I was hoping was adding a substantial amount of DO.

I just purchased the home last year and don't have any history on the pond. It was heavily infested with Coontail frown but also some great bass! The coontail was so thick it was just about impossible to fish by mid June. So we decided to treat the coontail with Reward. I treated 50% of the pond at a time, the first half of the pond was treated on 6/7/13 and the second half on 6/28/13. Within days of both treatments the Coontail seemed to die off and drop below the surface of the pond. Everything was looking great until last week!

I was hoping my 3 weeks between applications would be more than sufficient, along with bottom aeration that had been running all season� I had zero fatalities until 7/18/13.

Not wanting to experience this again and play the guessing game I purchased a DO meter this weekend. I took my first reading last night and posted the results below. The reading last night seemed good from what I have read on this forum. But I was shocked when I took my readings at 6am this morning. From what I have read they should not be below 3ppm. I didn�t see fish gasping like a few days ago.

Based on these readings does it appear the aerators aren�t adding enough DO to the pond? Any other thoughts or suggestions would be greatly appreciated.

1.5 Acre pond, 8� max depth.

DO Reading MW600 Meter
7/21 6PM Near Dam
12� 16.5
24� 8.5
60� 3.7
72� 3.1

Middle of pond
12� 12.3
24� 7.5
60� 1.2

Near surface aerator
12� 7.0
24� 5.9
60� .3

7/22 6AM Middle of pond
12� 1.1
24� .8

Near surface aerator
12� 1.1
24 .9



Could you please provide the depth profile of your pond in correspondence to the above readings? It appears that you have supersaturated oxygen conditions near the dam in 12 inches of water. This indicates either a very high phytoplankton count or aquatic plants in that area. I suspect the former condition rather than the latter..

Also, FWIW....for coontail control....I personally like Aquathol K over Reward for several reasons. Aquathol K provides a "slower kill" (reduces chances of oxygen crash) in addition to being fully biodegradable (Diquat is not). Also....check out what Diquat based herbicides do to your pond "friends" Daphnia hyalina at normal use rates... ..

Remember....some level of native aquatic plants such as coontail (Ceratophyllum spl) are beneficial for your pond.....




Last edited by Jeff Gray; 07/22/13 03:33 PM.
Jeff Gray (Aquatic Biologist)
"Jack of All Trades.....Master of Some"