Pond Boss Forums Thread Like Summary - Water clarity in a new northern pond

My 0.5 scre pond was dug in December and filled to 11 feet deep over the winter and spring. I stocked a few pounds of fathead minnows in June. Lots of frogs, tadpoles, and some turtles.

The water is exceptionally clear, about 7 feet with a Secchi disk. Total Alkalinity is 170 ppm, measured with a swimming pool test kit.

Is this normal infertility of a new pond start up? Do I need to consider fertilizing or will Mother Nature do her thing and eventually develop photoplankton blooms when more fish and nutrients are introduced?

I saw this "Pond Minnow and Plankton Food" at Smith Creek, which seems like a nice first step. Does anybody have experience with this stuff?

https://smithcreekfishfarm.com/products/minnow-plankton-feed

Knobber asks - " Is this normal infertility of a new pond start up? ".. water is exceptionally clear, about 7 feet with a Secchi disk. Total Alkalinity is 170 ppm..

Some ponds with the "right" soil conditions can start life with clear water. Often low alkalinity soil results in clear water. As nature adds nutrients more fertility gets added via water shed runoff and organic inputs.

What are your goals for the pond? Why the concern with a new clear water pond??? Clear water has many benefits. . These goals should determine how you manage the pond. Many ways to manage a pond; from doing nothing to intensive management.

I like clear water ponds. I do not like to add fertilizer to ponds especially northern ponds as you have already read. I think fertilizer creates more problems than it solves. See later. As the pond ages the water clarity will change quite a bit during the entire year depending on added fertility. What lives in the pond can affect the water clarity. Clarity of 7 ft does have good phytoplankton and zooplankton populations, just not lots of it. There is an ample food chain developing and what develops and how much of it there is depends on amount of fertility. Clear water ponds can grow big fish just not very many - only a few to several / acre. Clear lakes have good fish communities. I work on water samples from some municipal reservoirs with 15 to 18ft of water clarity where there is a very good fishery.

You can still produce lots of fish in a clear water pond by feeding the fish and not needing to add a fertilizer. Feeding fish adds "natural" nutrients to the system via fish manure and the pond soon looses its 7 ft of clarity. How much you feed determines how many fish you can grow. How you manage the numbers of fish determines how big they grow. A fish can grow as long as it lives as long as it has food to excess for more growth.

The main negative of clear water in a pond is light penetrates deep where plants get enough light to grow. This if one reason why many southern ponds are fertilized to limit sunlight penetration and growth of rooted plants. Plants and filamentous algae tend to create clear water by using using and absorbing nutrients and robbing nutrients from the phytoplankton types of plants. Less phytoplankton reduces the food chain for fish. Good and Bad - depending on GOALS. Once plants get introduced into the pond, 7 ft of clarity can result in light penetrating enough so plants / algae can be growing 20ft deep. Good and Bad. Plant introduction can come from lots of pathways. Plant seeds and spores from the dirt. A main pathway for introduction is animals and birds visiting the pond. Waterfowl manure has lots of weed seeds and algae spores. Wind carries algae spores and dust/dirt Water from stocked fish contains algae and zooplankton species sometimes weed fragments.

Basically the more plants of any type that grow in a pond the more plants that will die and the faster the pond ages by dead plants filling up the pond. As soon as you filled that dug pond with water NATURE wants to fill it back up with dead plants that lived and died in the pond and silt from runoff. How fast the pond fills with dead plants is based on it fertility and amounts getting into the pond. Nutrients grow plant. It is called pond / lake succession. Ponds are big earthen collection bowls with no drain.

One more thing about a clear water 7ft of clarity pond. It will grow trout longer without aeration than a cloudy green water pond because oxygen is produced in deep cool water. As soon as clarity is lost, oxygen production in deep water stops. This is why some clear water quarries or clear lakes can grow trout all year - DO production in deep cool water.

With a temperature profile like the one shown above AND with water clarity of at least 4 ft with 11 ft of pond depth and no aeration you should grow trout in that pond until the water clarity drops to 3ft. When that happens in July -Aug the trout will very likely die. I suggest that you perform two more temperature profiles. One in mid July and one in mid to late August. Also record water clarity with these tests. Use a Secchi disk or a home made all white one for most accurate clarity measurements. Clarity measurements will provide a good idea of depth for DO production. Post the results here in this thread. This info will give a good idea how well trout might survive next year if your water stays with 2023 clarity of 6-7ft for a 11-12 ft deep northern pond.

Fertilizing is very risky.
Lusk's recommendation of ideal clarity of ~24" is not qualified and meant for application in southern fish productivity ponds. Dr Dave Willis Fishery professor PB member recommended not to fertilize northern fish ponds. Fertilization only works well with owners experienced with fertilization or they are temporarily lucky. Long term fertilization without careful monitoring the pond is prone to a DO crash due to development of too strong of a bloom (vis 8"- 13") that consumes too much DO during several cloudy rainy days. Dave Beasley at Solitude Lk Mgmt and Troy Goldsby well known Professional Lake and Fishery Manager have also discussed this problem in PB Mag on internet Sitting Dockside. Over fertilized blooms usually cannot have the brakes put to them and numerous problems often occur. After years of use we are now discovering or learning that fertilization with an improper balance of nitrogen - phosphorus can often produce blooms composed primarily of Cyanobacteria (bluegreen algae) and not the beneficial other groups of planktonic algae. Very few places have the ability to properly identify what algae species are causing green water. Green water is NOT always beneficial for good water having ample zooplankton / fingerling foods. These 'Cyano' algae can be toxic and be problematic and are definitely not good beneficial fish food.

Some of the new pond fertilization philosophy "ideas" or concepts are now saying that the ideal clarity is around 30"-36" and not the old 16"-24" visibility. The increased clarity ideas of 30"-36" are to less likely to have Cyanobacterial blooms and still have good fish production. Visibility of 36" usually allows natural DO production down to around 6-6.5 ft.

Trout - No matter what species of predator type fish you stock including trout, I would stock some ( 2-3 lbs) FHM ASAP to get them started before adding trout or your other fish. No pellet feeding means the number of predators (trout) that you stock should be fewer numbers than those for a higher production type of pond where fish are fed pellets and / or pond is fertilized. . The more fish that are introduced and allowed to multiply the more likely the water clarity will decrease. Feeding pellets will also reduce water clarity and make it happen sooner due to increased fertility and higher amounts of fish production. More fish means more manure and more manure means more fertility to grow more plankton and reduce water clarity.

See this from the archives on fertilization.

https://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=96127#Post96127


Note - Bill I am copying your post and adding it to the fertilization archive.

IMO for the long term utilization of trout (and SMB, YP, RES ) probably the best plan is to continue with the plan of Fall trout stocking and harvest them before the LMB spawn in your region probably 3rd week in May or maybe as late at June 10-15?. If it were my pond in mid-Michigan and I wanted trout, I would monitor the water clarity (secchi disk) and the temperature profile as you have done so far this year. Whenever the water clarity drops to below 4.5ft with bottom water temps still at or below 68F trout do not need to be harvested. When the bottom water hits 70F harvest the trout.

Important. When the water clarity drops below 4.5ft Secchi disk in your Michigan 11 ft deep pond, all bets are off for trout summer survival; with or without aeration.

Having or maintaining a cold water refuge with clear water of 4.5ft is entirely up to you and your goals. Pros and cons to it.

Looking at the temp profile from 7-26, the trout only have <2' of water to live in without at the bottom of the pond that is below 70°F, and we have no idea what the O2 levels are down there. Just because the water is <70°F doesn't mean that there is enough O2 for them to survive. I have had trout stay alive in 80°F water that had aeration and a surface agitator running. So if enough O2 is available it might be possible for them to stay alive all year long in your pond.

There is an O2 system on the market that will put O2 into water below the thermocline and not disrupt the thermocline. But you'd better be sitting down when you see the price of it.