Pond Boss Forums MANAGING AN EXISTING POND Fertilization 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

I don't know about the soils and subsoils exposed in your pond basin, nor the content of the incoming water.

However, the formula for most ponds is that fertility increases going forward in time!

Further, that minnow "chow" seems expensive compared to firing up the natural productivity of your 0.5 acre pond. Maybe read some of the pond fertilization threads, and see if any show a successful methodology that matches your geographic area?

Thanks, 'Rod. The incoming water is precipitation and runoff. The soil results are here, with classification of "loam."

https://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=556652#Post556652

I will read up on the fertilization threads.

Runoff from ??? Forest, grassland, cropland?

Runoff is mainly from my backyard and neighbor's yard. Grass. Grass is not fertilized. No livestock on the grass. Also brush and woodlands surround some of the pond.

Photo was taken last summer before cleanout and excavation of the new pond.

No lawn fertilizer, no crop fertilizer, no fertilization from livestock manure.

I suspect your pond might benefit from a little deliberate fertilization!

(Hopefully, you find some good threads in your search, or an actual expert drops in with some solid advice.)

No luck on the thread search. Most posts relate to Southern ponds and nothing similar to my situation that I can see.

I don't know of any pondmeisters around me who purposely add fertilizer. Everybody is paranoid about algae and weeds, and of course the pond management bulletin from the State poo-poos fertilizer and feeding fish for fear of excess nutrients.

I contacted a couple local pond management companies looking for some pond start-up advice. Instead, they wanted me to purchase Aquashade and sign up for a weed control program. The pond is only 6 months old and this is just the first growing season!

Fish hatchery's like Zetts sell fertilizer for ponds. You could try your local hatchery to see if they have any and what they advise.

I am no expert, but in a similar position as you. Newly reworked .5 acre pond in the north. Mine is still slowly filling, but I have had multiple blooms in the pond so far. Right now it looks like peanut butter after the hard rain a couple days ago, but it's starting to settle out.

Weeks ago after the first bloom the pond got pretty clear. I could see the bottom in 4' of water. Plenty of life in the pond so I stocked some FHM and GSH. We'd get a rain and the pond would cloud up a little and then turn pretty clear in a day or so. I added some alfalfa hay flakes around the edge of the pond to provide some cover and hopefully spawning habitat for the shiners. There wasn't any plants or grass yet as it was only 1/4 full. A few days after adding the hay the water turned green, next day it was even greener, then it slowly turned a brownish green color. Settled in on that nice olive green color and stayed there for a couple weeks until this last heavy rain. Clarity was down to 14"-18" and no surface growth or films that I saw. So the Hay must have added the nutrients the pond needed to get the good blooms. Long term I do not know.

I have 25-30 acres of hay fields that drain to the pond. No runoff has made it to the pond yet since it's been dug as we've been very dry and whatever rain comes down it is absorbed. I do use fertilizer and lime on those fields when needed, so I'll keep and eye on things.

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.

Fish hatcheries are the only places where I think fertilization is good in northern ponds. Fertilization of ponds is tricky and very difficult to do it correctly in all ponds even southern ponds. Improper fertilization can cause lots of problems such as fish kills, and growing the WRONG plants / algae.

Thanks, Bill. Great response.

I am not opposed to a clear pond. I think it is awesome! Thanks for confirming my suspicions. Fertilizing seems risky to me, and it was never part of my plan until reading this forum.

I'll be honest, the more I read on PB, the more confused I become. Lusk says ideal clarity is ~24 inches, hence my concern that my clarity is 7 feet. The experts also say that a clay bottom with compaction is needed to hold water. My pond was dug out of loam and peat and holds water just fine (so far). I think there is a big difference between pond management in Texas vs. Michigan, and every situation is unique.

My goals are SMB, YP, maybe RES and HSB. I lean more to the passive side of management. But, my pond is new, so I want to give it the best possible chance and not screw up anything right off the bat.

@Bill Cody, you also said:

"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."

Before I start introducing bass and perch next year, I would like to give RBT a try this fall and see how long into next summer they may survive. Do you recommend aeration no matter what, or would the trout prefer more stratified water with a deep water refuge?

My pond, currently not aerated, has a temp profile like this:

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.

I'm with Bill on the No Fertilizing part. The water will be fine without it. Stock FHM asap, unfortunately you live in the republic of Michigan where you have to get the State's approval to stock any fish in your pond. You own it, they control it. The only way you can get around needing the state approval is if you do not have any inflow or outflow pipes in your pond, even if they outflow onto a grassy pasture. See my post in your aeration thread about diffuser/air station placement for the winter.

I don't think Michigan is as harsh on private pond owners as you say:

https://www.michigan.gov/dnr/managing-resources/fisheries/stocking

Stocking Private Ponds and Public Water Bodies
Are you looking to add fish to your private pond? If the water body you are stocking is not permanently connected to any other water body and does not have public access, you do not need a Public Waters Stocking Permit.

My pond is a hole in the ground. No inlets, outlets, pipes. I am fine.

The only thing to watch out for is that Asian carp are prohibited. This includes Grass carp.

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.

@Bill Cody, here is the updated temperature profile, now that I have my aeration system up and running for about two weeks. Wow, I am amazed at the temperature uniformity! Water clarity remains 6 to 7 feet with a Secchi disk. The only fish in the pond are FHM, and there are thousands of fry hanging around the plumes of the two airstations.

I am sad to see the cold, deep water fish haven disappear, but I assume the lack of a thermocline is less risky to fish and aeration is better overall for the health of the pond.

Recall, this is a newly dug pond, only 8 months old. My plan is to stock trout this fall for put and take fishing until next spring/early summer. Then, introduce YP, RES, and SMB next year.

Very good chart for temperature profile of the pond. Yes the pond had a cool water refuge until aeration was initiated.
How long each day are you running the aerator in your 0.5ac pond????.

With water clarity of 6ft all summer,,, the DO on the bottom should have stayed high enough for trout all summer. It would have been very interesting to test it to see if I know what I am talking about. It would have been very helpful and informative to see DO readings at 10 to 11 ft deep in July, Aug and Sept. The thermocline as at 7-8ft in July.

It would seem to me that if the goal is to have cool water for trout to live in as long as possible that you would want to aerate one small area (maybe a shallow 1/3 of the pond) to promote healthy bacteria, avoid anoxic zone in the shallows knowing that this area will no longer have a thermocline or cool water refuge. It seems like you would want to have a more clearly defined warm and cool water area in spring/summer/fall for cool water fish. Maybe at this depth aeration is not needed?

Bill, aeration is running 24/7 right now. Is that overkill? The winter plan is to use only one air station in about 3 ft of water near shore to maintain some open ice and air exchange.

DO meters are pretty pricey. Do you have a recommendation for an economical model for amateurs?


cc, good point. I considered the approach you mentioned. In fact, EasyPro recommends not putting an air diffuser in the deepest hole in order to maintain a deep water refuge. However, I figured my trout would only be temporary and not make it through next summer anyway, so I am favoring more oxygen/air lift over cool temperatures. However, Bill now has me thinking that the trout can survive the summer temps and use the thermocline. I am confused.

I have no game fish at the moment and can adjust the aeration any time. My pond is new, clear, and without a lot of decaying matter. Maybe I have a unique situation here where I can maintain trout for a few years? I am not planning to stock trout until October, and the pond would be naturally turning over to a constant temperature at that time anyway without aeration. Correct?

I guess I now have two scenarios with questions:

1. For a year round trout pond, should I maintain a thermocline/cold water refuge (assuming DO is adequate), or aerate the entire pond in spring/summer/fall?

2. Is it possible to have a fishery of RBT, SMB, YP, RES (maybe), and FHM? What aeration strategy should be used in this case? Can bass and trout coexist as apex predators?

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.

Very good point! Only 2' of water is below 70 def F, and that is localized to the deepest hole in the pond, which is not that big around. Yes, I have no idea what the DO is at the moment.

I recall seeing that O2 system advertised somewhere. Big bucks.

OK, I will stick with aeration, and plan on a trout harvest/die off by next summer. In addition to the diffused bottom aeration, I do have a fountain that the previous owners left behind (and wifey likes it). It can provide a little bit of supplemental surface agitation that the trout may appreciate.