Scum on Pond

[morewater]

I concur with Meyer on the aeration issue.

Sub-surface aeration for a pond of this volume and depth will require, at the very least, a 1/4hp rocking piston compressor with at least 2 diffusers. The compressor unit would ideally be run 24/7, but a programmable timer could be utilized if absolutely necessary. You would need to factor in the cost of sinking airline, composite diffusers and a protective housing for the compressor as well.

Treatment with a product such as Muck-Off will accelerate the breakdown of the accumulated debris that is sure to have accumulated on the pond bottom. This product needs to be used on a continual basis. They're pellets that are simply strewn across the pond surface at the specified rate/time schedule.

These two regimes have cleared many a farm pond for me, but it is not an overnight process, nor is it inexpensive. Results typically take 30-60 days for a significant response.

I have installed a couple of windmill aerators in the past couple of years where access to power or the cost of power was an issue, but when the wind isn't blowing............

The longer you leave it, the more arduous the process.

 

[MitchM]

That pond is basically a catch basin for the surrounding hillsides. Along with what looks like horse manure on the one side of a hill, you can expect ongoing excess nutrient issues.
What is the water flow like? Is there a stream running through this pond?
Would there be any way to increase any water flowing through the pond?
Can you increase marginal plantings or divert hillside runoff?

 

[budgenator]

Thanks, Meyer and Peter. It sounds like aeration is what is needed. My boyfriend had been hoping the pump he installed that shoots a strong stream of water into the air would induce enough oxygenation, but obviously not. We just looked online and it seems a pump for an acre-foot pond, which we estimate ours to be, runs around $700 (which is why he was dragging his feet about getting one). Do either of you (or anyone else who wants to chime in) have a recommendation for a pump and/or sourcing one? And how long, how often, and during what times of year would it need to be run? Thanks so much for your time in answering and your suggestions.

Meyer is spot on, but remember it's a lot cheaper to move water with air than it is with a pump, this is something like what you would need http://www.koiphen.com/forums/showthread.php?142548-Mud-pond-airlift-circulator-and-aerator it will bring the water up from the bottom to the top where it can get some oxygen. In the worst case you might need to dredge out the accumulated leaves breaking down on the bottom as well.

The Air pumps to run the mud pond airlift circulator and aerator are a lot easier to find now, after looking at more traditional ponding suppliers check hydroponics and septic suppliers too. If your BF is at all handy, he can get it all going for $200 - 250.

 

[baker_eliz]

Okay, everyone. We installed a SRC25 1/4 hp pump with dual diffusers. It has been running 24 hours a day since April 20th.

The pond is now so murky that we can't even see the koi. What is going on? Is the bottom being stirred up that badly? The turbidity has gotten much worse.

We thought this would help turbidity significantly, based on numerous recommendations. What else can we do?

Thanks, everyone.

 

[Meyer Jordan]

We thought this would help turbidity significantly, based on numerous recommendations. What else can we do?

Perhaps we did not clarify what we recommended. Your initial concern was with floating algae and possibly some planktonic algae also. As too turbidity caused by algae, aeration is the solution. However, an earthen pond that houses Koi will never have clear water for it is a Carp's (Koi) nature to spend its time rooting around in the bottom of the pond looking for food. This, of course, keeps a certain amount of detritus in suspension at all times. The greater the number of Carp, the more turbid the water. Without the Koi, you could very well be able to see the bottom of the pond.
Sorry if you were led to believe that aeration was an absolute cure for turbid water,

 

[baker_eliz]

Thanks, Meyer. We are not looking for an absolute cure, but the pond is MUCH worse with the aeration. Will this resolve itself over time, or should we add something to coalesce the suspended particles? I'm beginning to think the aeration was a mistake. The pond has never looked so bad in 40 years.

 

[Meyer Jordan]

I'm beginning to think the aeration was a mistake.

Adding Oxygen to a pond is never a mistake.
What may have happened in your case is twofold-
First, the diffuser plates may have sunk somewhat into the accumulated sediment on the bottom of the pond. This, of course, would put more detritus in suspension.
Secondly, by improving the Oxygen level in the pond and circulating it to the bottom. The bacteria than have the Oxygen that they need to begin breaking down the accumulated sediment into smaller size particles which would easily be suspended by both the diffuser and the Koi..
It, unfortunately, will not clear overnight. You are dealing with up to 70 to 80 years of sediment accumulation. It may take weeks or months to overcome this.
For what period of time are you supplying aeration? Ideally it should be done at night from sundown to sunup.

 

[adavisus]

A pond can accumulate 4" of sediments a year. If the turbidity bothers you, it's overdue dredging the stuff out of the deep areas

Dredging every couple of years will help improve the water quality. Or, a regular habit of clearing some out of the deep area, often. Best done when waters are cool, calm and fish less active.

The pesky so and so's have all night rooting around in the mud, searching for tidbits...

 

[sissy]

give it time nothing happens over night

 

[baker_eliz]

First of all, many thanks to Meyer and everyone else who is responding. I can't tell you how much we appreciate being able to ask all these questions. --elizabeth

1. Sunken diffusers: While of course it is possible the diffusers have sunk into some of the sediment, the sand weight underneath the diffusers are about 6" tall and the air bubbles coming to the surface are clear and the turbidity in the immediately surrounding water appears to be no worse than anywhere else.
2. Dredging: How would one go about doing such a thing when there is no way to get any kind of large equipment to the pond?
3. We have been running the diffusers 24 hours for the last 2 months. Should we be running them only at night? How much time should we give this? Any idea how long before we should see (positive) results?
4. Is all the detritus in suspension harmful to the fish?
5. We added a Pond Boss PRO Block, Bacteria Maintenance, 5 lb. to the pond today.
6. We are wondering about applying soluble gypsum. How does one go about doing this? We have read that simply broadcasting by hand on the surface is barely, if at all, effective. And, again, there is no way to get any kind of large equipment to the pond. We have a small motorless rowboat but no pump. We have read about doing it via slurry, but no one has said how to actually do that effectively.

Thanks, again.

 

[adavisus]

Dredging can be as simple as setting a plank on a pedestal in the deep area, walking the plank with a big sturdy net and a plentiful supply of buckets....

When what is dredged settles in the bucket, pour the clear water off. The gunk can be heaped where you have a veggy bed that likes fertile mud

A fairly pleasant task on a cool sunny Autumn day

 

[baker_eliz]

Thanks, adavisus, but I don't think that is very practical for a farm pond of this size.
--elizabeth

 

[Meyer Jordan]

First of all, many thanks to Meyer and everyone else who is responding. I can't tell you how much we appreciate being able to ask all these questions. --elizabeth

1. Sunken diffusers: While of course it is possible the diffusers have sunk into some of the sediment, the sand weight underneath the diffusers are about 6" tall and the air bubbles coming to the surface are clear and the turbidity in the immediately surrounding water appears to be no worse than anywhere else.
Considering the age of this pond, there is very likely much more than 6 inches of sediment on the bottom.
2. Dredging: How would one go about doing such a thing when there is no way to get any kind of large equipment to the pond?
You certainly have an access dilemma. Another option (which you won't like is to drain the pond and remove the sediment manually. Short of doing that, your present use of an aerator is your only option.
3. We have been running the diffusers 24 hours for the last 2 months. Should we be running them only at night? How much time should we give this? Any idea how long before we should see (positive) results?
24 hours a day will not hurt, but running aeration only a night would be sufficient
4. Is all the detritus in suspension harmful to the fish?
No.
5. We added a Pond Boss PRO Block, Bacteria Maintenance, 5 lb. to the pond today.
Waste of money. this pond (with the aeration) will already has all of the bacteria that it can support
6. We are wondering about applying soluble gypsum. How does one go about doing this? We have read that simply broadcasting by hand on the surface is barely, if at all, effective. And, again, there is no way to get any kind of large equipment to the pond. We have a small motorless rowboat but no pump. We have read about doing it via slurry, but no one has said how to actually do that effectively.
Gypsum can be effective in reducing TSS (Total Suspended Solids), but it would not be fast acting either and \, in your case, might require multiple applications.

Is the aerator somewhat centrally located in the pond? And in a deep section?

 

[Jhn]

6. We are wondering about applying soluble gypsum. How does one go about doing this? We have read that simply broadcasting by hand on the surface is barely, if at all, effective. And, again, there is no way to get any kind of large equipment to the pond. We have a small motorless rowboat but no pump. We have read about doing it via slurry, but no one has said how to actually do that effectively.

Thanks, again.

Dredging via a gas slurry or trash pump (2-3")would work, but would be pretty decent cash outlay on the pump and hoses necessary to do it. You would also need a spot where you could pump the discharged silt and a lot of patience. It will be a slow process, as you have to slowly move the suction hose around the pond bottom.

Basically how it works is the pump would sit on a float or rowboat, suction hose that reaches the bottom of the pond and enough discharge hose that will reach an area where the silt can be discharged w/o running back into the pond. The pump will suck the silt off the bottom of the pond along with the water. Just keep in mind it will also suck up any small fish or critters that wonder too close to the business end of a 2-3" suction hose.