Pond Boss Forums INTRO Questions & Observations Muck Eating Bacteria Experiment

This is what the program director of aquatics at the Ohio State University sent me a few years ago. I had a heavily silted in pond and was using muck reducer pellets from various manufacturers all to no avail. I ended up draining the pond and had a dozer come in and he removed enough muck to fill a ~1/4 acre field 3' deep full of muck. He held it in by creating a bowl out of clay, otherwise it would have just oozed back into the pond. If you could see how much muck was in that little 3/8 acre pond, you can then realize a few gallons of magic elixir will do absolutely nothing to get rid of it.




1. Regarding overall pond longevity, bubblers are usually best situated near/along the deepest water, but in sufficient numbers and power to circulate the whole water column. The point is to destratify, to mix, the water column. If you break up stratification, oxygen dissolved from the atmosphere across the surface of the pond should then be mixed throughout. If your diffuser plates are only in shallow water, you’re leaving the deep water to stratify, lose oxygen (that may release excessive phosphorus to the water column and may put you at risk of a summer fish kill), and may be facilitating the accumulation of much in the deep water, losing important volume. I don’t know how many you have or how your deep water lies trough the pond’s area, but two or three diffuser plates along the deep water is probably appropriate.



Enough circulation to turn over the pond’s volume twice each day would be excellent. The pond will mix naturally in the fall, so I ordinarily recommend you shut down the aeration system in the fall (no need to spend energy to artificially mix a pond that is mixed naturally). If you consistently ice over, you can repurpose the diffusers (moving them back to shallow water) to erode a hole in the ice). That only has use if you’re worried about prolonged ice cover and winter kill of fish.



2. I am skeptical of beneficial bacteria/muck treatments at present. Related products almost certainly don't do any harm and may in fact do some good, but I'm not at all convinced that they justify their expense from the perspective of longevity of pond function in whole.



Those products tend to be proprietary concoctions of facultative bacteria, some substance (enzymes or micronutrients) to promote their growth, or some combination of the above. Those "beneficial" bacteria do indeed consume muck/organic material. However, those bacteria need oxygenated conditions to be effective. Without oxygen, they’re not efficient; with oxygen, some related bacterial assemblage will be present along a pond's sediment and active anyhow. Because those products aren’t labeled as having any kind of pesticide effect, they aren't regulated; most makers don’t publish their ingredients—keep the ingredients as trade secrets—and so the ingredients can't be researched individually.



I search related literature periodically; I still cannot find any professional, peer-reviewed articles that support or refute the notion that these products substantially enhance a pond's water quality or slow the pond-aging process in whole. Thus, I'm skeptical regarding whether or not adding a jug of formula or handful of pellets to a volume of water the size of a large pond can make a pond-scale difference. However, some formulae may have useful localized effects (e.g., aggressive application around a dock or swimming area). Also, aggressive short-term treatment may “jump start” a depauperate bacterial assemblage, at least in the short term. Again, without peer-reviewed literature or controlled experimentation, it’s all just speculation.



Creating healthy habitat for beneficial bacteria by keeping dissolved oxygen circulating along the sediment throughout deep water (as with diffuser aeration) seems to me to have much greater potential to increase their populations and effectiveness. It’s usually recommended that bacteria treatments be made in conjunction with aeration; in such an application, it’s difficult to know how much recovery can be attributed to aeration alone. Thus, on pond scale, a properly designed bottom-aeration system seems to me a much better initial investment.



Of course, such bacteria have no effect whatsoever on inorganic sediment. If accumulated sediment is low in organic content and substantial enough to impede pond function, some form of physical dredging would absolutely be needed to regain it. Even with a fair amount of organic matter, if your accumulation is excessive, it might be time to bite the bullet and plan for a dredging operation.



I did pull up a satellite image of the address you sent. I saw several good sized ponds near there and am not certain which is yours. Most of them (the furthest north and east in particular) were forested enough to be concerning regarding their longevity. Trees to the west and south of a pond tend to speed up the aging process (to the east and north are less concerning and may even be beneficial). If there’s enough tree cover and input of leaf litter, you just won’t be able to keep up with biological degradation of the resultant muck. Once again, periodic dredging becomes the only way to maintain pond function.



3. Again, slowing its accumulation by effectively aerating deep water is the best bet for overall longevity. However, you may have a situation where you won’t be able to keep up with the input of leaves. Unfortunately, periodic dredging may be needed.



Do stay in touch. My classroom duties end when I post grades on Friday, and I should be much more available to these types of discussions after then.



Be well out there.



Best,





The Ohio State University