I will try this again. While Bob was posting just above, I was about finished w/ a lengthy breeze and then I hit a couple wrong keys & I LOST it. Try again, maybe not so lenghty this time.
Greg, I tend to agree w/ your plan, It's simple esp for pondowners who want to fertilize & do little physical mgmt and just want to fish in "clean water". Coontail is a big problem since it spreads fast and regrows from winter buds. I far as I know, can't manage it (or very tough) for a limited percentage of coverage.
I think Greg & I differ primarily just due to location. In the north (north of WVA, KY, MO, KS) most recreatiional ponds are not fertilized. Too hard or tricky to maintain a bloom & added fertilizer usu just grows rooted weeds or filamentous algae. Our ponds are often in fertile soils which makes them naturally semi-productive to productive. Fertilization can work in northern ponds but it takes knowledge and a N & P test kit or luck. Greg is very right, most people want instant results esp if they have to pay for the advice; no waiting. In my pond I prefer to use "aquascaping" using beneficial plants to grow and crowd undesirable and problematic types. Harvest, thin & manage the desirables and if they get unmanagable add just enough amur to help and improve the situation.
Mark L. & Others. Two pond oxygenation senerios (sp?).
1. Pond dominated with rooted plants or filamentous algae, water will be clear (vis. 4-8ft) then phytoplankton will be at lower densities: most oxygen for the pond is being produced by the rooted plants and/or fila. algae whichever is dominant.
2. Few or no rooted plants, water greenish & cloudy or murky w/ visibilities abt 18" to 3 ft. Phytoplankton densities very high & it dominates the plant community and collecively it is primarily responsible for most of the pond oxygenation.
Oxygenation with bottom aerators/diffusers will not add much oxygen to the overall oxygen budget of the pond. That is not their purpose; they are cheap hi vol. mixers. See the posts under aeration for clarification of this.
If the pond is managed & watched properly you very rarely will have a problem with very low DO. One needs to be knowledgable & AWARE of the repercussions of doing things to the pond that can cause large impacts on the plant or animal communities. Maybe a little harsh here but, neglect and/or ignorance cause a lot of the major DO losses in ponds.
Many pond owners intentionally or unintentionally do things to their pond which puts the pond "on the edge" or brink of a potential problem. Then if a weather event or something else "tips the scales" the pond and its inhabitants are quickly in deep trouble. For example: Let's grow lots of fish and lots of big fish. To get this done we decide to fertilize the pond. We succeed and have this really nice bloom going like gang-busters and water visibility is about 16"-18" fish are growing great & bigun's too. For several years things are great we are teh best pondmeisters on the block THEN 'ol Mother nature' gets ornery and gives us rain and dark cloudy weather for three or four days. We don't check (neglect) our pond and don't know of any reason to (naive) AND on the 4th day we go to the pond and see lots of dead fish and fish swimming at the surface. . WHAT HAPPENED??? A heavy phytoplankton bloom can collapse after several days without adequate sunshine or if it runs out of "steam". Tremendous numbers of tiny dead & dying plants immediately start decomposing/rotting, due to bacterial action and the developing bacteria bloom uses or breathes lots of oxygen dissolved in the water. In actuality the bacteria creating the bloom are thousands & thousands of times MORE numerous & are much, much faster reproducing than the algae were. Thus, they use oxygen much faster than the plants, even if not dying, can produce. Remember the bloom algae are now sick & dying fast. Oxygen is consumed faster than it is being produced and quickly often in hours a DO shortage results - now we have suffocating fish! This often happens late in the night or just before dawn. Several hours of complete darkness magnifies the problem. The pond was "on the edge" - vulnerable to a algae bloom crash.
