Pond Boss Forums AERATION Systems questions Water clarity around diffuser boil

I just started aerating my 2 acre pond and have noticed a discoloration of the water in 2 of the diffusers boil. I have a Gast 3/4 HP Rotary vane compressor that produces 7.2 CFM air flow with 3 diffusers. The water is 22 ft deep at one diffuser, 17 ft at the second diffuser, and about 10 ft at the third.

There is very little if any discoloration of the water boil at the 10 foot diffuser, however, the other 2 diffusers have a discernable cloudy discoloration to the boil.

I first thought the diffusers may be upside down but I've repeatedly tried lowering them back down, but keep getting the same result. (Any ideas of how to ensure they are right side up without diving down 22 feet?)

If the diffusers are not upside down what is causing the discoloration? I had 3 foot of visability before starting aeration. Any ideas??? Thanks.

Diffusers should be built / constructed so they decend in an upright position. If not make changes in the design or frame assembly. Diffusers should have a low center of gravity to minimize tipping and a wide base. Weighted airline can cause a "pull" on the diffuser as it decends. Maybe try lowering the diffuser with it operating. Airflow may help hold it upright.

If you are sure the diffusers are upright AND the diffusers have not settled into a deep muck layer of an aged pond, then this is a possible explanation. Deeper diffusers that have a discolored boil could be lifting settled materials and or detritus to the surface from the deep water layer or zone. Normally the layer does not contail lots of stuff until later in the summer. The top productive layer generates organic materials that settles or "rains out" into the deeper waters. As this dead material settles it can collect in the cooler deeper layers as a band of dead "junk" that does not settle out at a normal rate due to differences in water temperature and water density. You may be seeing the layer of "junk" being brought to the surface again.

If this is an old pond then I think the diffusers are siting in deep muck. If it is a new pond (1 to 6 yrs old) then I am concerned that the diffusers may be tipped or not lying flat on the bottom.

Thanks Bill. The pond was finished August 04 and filled in December 04. The water has steadily been clearing since January. Secchi disc readings went from 12 inches in Jan. to 36 inches a few days ago. Due to the ponds age I know it's not muck.

When I've raised the diffusers which are attached to 18"Lx18"W plexiglass squares that came with the unit, I've seen clay on the plexiglass, usually the bottom like it was sitting properly on the bottom.

What suggestions do you have for a set-up other than the plexiglass I already have the diffusers attached to that would keep the diffusers upright as they are lowered?

I kind of think you were right about the diffusers in the deep water bringing up material that hasn't settled all the way to the bottom yet. The discoloration is about 15 feet in diameter around the boils from the diffusers. I got to looking this afternoon and even the 10ft diffuser has a discoloration around it. Secchi disc readings range from about 16-20 inches in the discolored areas and 32 inches in the areas outside of the boils up to 36 inches near shore.

What exactly is 'detritus' and should I stop the aerator if it is bringing it up?

Any further answers would be appreciated. Thanks.

MM, Do you have square airstones or rubber membranes mounted on the plex ??

MM - Detritus is fragments or particles of living or dead material sometimes called debris. This can range from silt, dead algae cells to wind blown stuff from outside the pond bascially anything that comprises solid particles in the water. In limnology (freshwater science) it is usually considered primarily dead organic material.

I have found the flat plate diffuser bases can be difficult to set properly on the bottom. The airline weight wants to pull and distort the proper vertical discent of the diffuser when lowering it from a boat. Sometimes weight on the under side of the diffuser can provice more ballast and help keep it upright. I have my own method for use in small ponds where we can pull the diffusers in from shore, however my method is not profesional looking. Maybe others have more experience with those type of diffusers in bigger ponds such as yours.

Yes, we can eliminate deep bottom muck as a cause for your water cloudiness in the upwelling boil. You are probably dealing with spring time sedimented particles maybe mostly very fine sediment-clay particles that have accumulated in a band at the thermocline. Your pond is fairly deep the clay-silt band may not have completely settled to the bottom. You are now pumping water up through the thermocline and lifting the sedimented particles back to the surface.

You have numerous options on how to deal with this. If it was my pond and since you are in OH, I would only run the diffusers 6 to 8 hours per day until the upwelling water runs clear. Or leave the diffusers off for a couple weeks and then restart them and see what the clarity looks like. I think you started running aeration too soon for typical OH standards. I tell most people to wait till the pond clears up (vis 5ft - 8ft) before running aeration, often this is in the second year. Otherwise, if you aerate too early in a new pond you get the problem you have now. Aeration keeps moving the water -sediment-clay suspensison and it has a hard time settling becase of the constant movement. If it is organic detritus particles then they will can decompose/rot in to basic elements while in suspension and in highly oxygenated conditons. Clay soil will not decompose. NOTE - cloudywater is not all that bad. It naturally reduces sunlight penetration and thus reduces a lot of bottom plant growth icluding filamentous algae and Chara with is a problem in new ponds.

Ted, I have rubber membrane diffusers attached to the plexiglass.

Bill, I went out today and the water has apparently turned completely over due to the fact there is no discernable difference between the water boil and the rest of the pond. The surface temp is noticably cooler than yesterday(I'm kicking myself for not getting temp readings before starting up the aerator) and secchi disc readings taken in three different areas of the pond were consistent at 22" visability. Big difference in visability and color in 24 hours. Visability was 36 inches with a nice green color, today the color is not quite brown, not quite green with a cloudy appearance.

I assume since the pond has turned over the visability shouldn't get any worse. Am I correct in assuming that? My main concern is the 1000 BG/Red Ear mix I stocked and the 2000 Fathead minnows that are in there. Does this reduction in visability affect the growth of the fish? I'd like to stock my bass in Sept./Oct. and want the forage to have a good start. Any suggestions as to the best course of action(let the aerator keep running and see what happens, shut it off till next spring)? Thanks for any feedback.

Visibility should not get much worse. You can monitor it to verify its clarity over the next several weeks. Weekly readings are okay.

Fish will do fine in 20" to 24" water clarity.

If water clarity does not get any better by August or mid August and you want the pond clearer then you can turn off the aerator for the season. Unvegetated and mud exposed shorelines will produce turbid water during windy days. The pond should clear up quite a bit in late August, September and early October without aeration. In mid late October the natural circulation will begin and contunue up to freeze up. After ice out the pond should be quite clear (vis 5 to 7ft). Start aeration back up in mid April of 2006.

Thanks for the response Bill. Sounds like a good strategy. Thanks again for taking the time to respond, it is much appreciated!