Pond Boss Forums STOCKING A NEW POND Creating the food chain Fhm fry survival in very clear water

[u][/u]I did a reset on my fifty year old pond last summer. Cleaned out all of the muck and it filled during the winter. I transferred fhm and GSH to the pond placed spawning structure and they are doing their part. I stocked rbt and am feeding them trout food my water is very clear it's great for watching the trout but I am curious if there is enough food for the fry to survive without creating an algae bloom. As a side note I have several Canadian geese and several ducks that visit regularly plus one hen mallard with ten ducklings

Those geese and ducks are actually supplying a significant amount of fertilizer to the pond.

Keep watching this spring and summer to see if you do get an algal bloom.

cb100, fry survival is low in clear water. If your hardness and ph are good then try an organic fertilizer like cotton seed meal, alfalfa, or rice bran. Use 50 lbs/acre for the initial treatment and then follow up with 25 lbs/acre as needed. Allow at least 10 days for the bloom to establish. If you don't get a bloom you may need to adjust water parameters to values favorable to phytoplankton.

jpsdad (and others),

In general, is fry survival low in clear water due to lack of sufficient food sources or due to predation? (Or more likely some combination of both.)

Will the Golden Shiners eat FHM fry? (Especially if the pond has low productivity and is not producing much in the way of alternative food sources for the GSH?)

Either way, the advice to naturally fertilize should work to mitigate a multitude of problems. Any downsides at this point in the life of cb100's pond for trying to induce several algal blooms a year? (Assuming the pond DO is sustained far from the crash level for the RBT.)

It is mostly lack of sufficient food ... but also a combination ... I think.

Yes, adult minnows of both minnow species will eat fry.

The organic route has several advantages but the slower availability of nutrients lends to a smoother and more modest bloom (buildup and dissipation more like a hill as opposed to a mountain). The rates I recommended are very low and not likely to cause an excessive bloom. These fertilizers can be safely added for the initial treatment up to 300 lbs per acre for fry production. Follow ups are usually restricted to no more than 50 lbs/acre as needed but no more frequently than weekly and only when needed. These heavier doses are to maximize fry and fingerling production in hatchery ponds. Aeration generally isn't needed at these rates.

Thanks for the response. I am glad to see the birds and figure their fertilizer would help some with my algae bloom it is a choice between rapid minnow growth and good visibility of the trout. Is there anything I can introduce for fry food without affecting the whole pond?

How clear is very clear? How deep can you see a white coffee cup on a cord?

I haven't tried a disc test but I placed several white plastic buckets for spawning habitat. One went down to about eight feet and I can clearly read even the small writing on it . I would estimate visibility at about thirteen feet

Okay - plankton is low density when clarity is 13ft+, although at this clarity there is still adequate plankton to grow some fry. I would not fertilize unless later you want to fight more algae and weeds that will grow as nutrients accumulate to make pond more eutrophic. Once nutrients are in and accumulate they are very difficult to remove. IMO appreciate your clear water as long as you have it. Feed some good quality fish pellets if you want to grow more fish rather than fertilize, the nutrients will eventually accumulate to eutrophy the pond.

Thanks for the response that's what I was hoping for. I have been releasing some water from my bait fish pond the pipe is the lowest point of the bait fish pond it dumps some of the muck into my big pond not a whole lot probably the first thirty gallons is almost black and it creates a small bloom for a while.

Feed or organic fertilizer. Its all organic fertilizer except that at equal weights ... a feed will put much more nitrogen and phosphorus into the pond. Eventually you will have fed enough of the feed to be nitrogen equivalent to 50 lbs of alfalfa for example. This will occur with A 40% feed when you have fed around 22.5 lbs of feed. The major difference will be that the feed wastes will have a very low C/N which means that it will be more stable. This means it will be more like muck will not produce as good a bloom. The higher C/N ratios of organics puts a lot of energy into the pond which is good for zooplankton and phytoplankton as well. Anyways, nice to hear that your pond is new again.

I am currently feeding 42 percent trout food to the fish and putting out 32 percent catfish food that the ducks are eating I have some fertilizer for ponds that I may use a little down the road but right now I am enjoying the visibility. There is some submerged vegetation for the fry to hide in

Can you elaborate on the formula you are using to figure 22.5lbs of food is the same as 50lbs of alfalfa, nutrient-wise? I'm struggling with this a bit.

I don't recall saying that. For example, it would take less than 12.5 lbs of feed to be equivalent to 50 lbs of alfalfa on a phosphorus basis. So how they compare depends on which nutrient we are making the comparison. Above I compare N which is proportional to the weight of protein. Good alfalfa is 18% protein by weight so its just a ratio when equal equal weights are considered 18/40 = .45. Or by weight alfalfa has 45% of the weight of protein as a 40% feed ... since the weight of nitrogen is proportional to the weight of protein ... there 45% as much Nitrogen in alfalfa as there is in a 40% feed.

"Eventually you will have fed enough of the feed to be nitrogen equivalent to 50 lbs of alfalfa for example. This will occur with A 40% feed when you have fed around 22.5 lbs of feed. "

This is what I was referring to.. maybe I misunderstood.

I'll take responsibility for not describing it better.

Take an arbitrary amount of alfalfa, lets say 50 lbs. There is 0.18x50 = 9 lbs of protein.

To add an equivalent amount of protein using 40 % feed. 9/0.40 = 22.5 lbs feed.

Nitrogen in 50 lbs of alfalfa= 9/6.25 = 1.44 lbs Nitrogen
Nitrogen in 22.5 lbs of 40% feed= 9/6.25 = 1.44 Nitrogen

So 22.5 lbs of 40% feed is nitrogen equivalent to 50 lbs of alfalfa. This method of calculating the nitrogen content is widely used in agriculture. Not every protein molecule is 16% nitrogen by weight (1/6.25 = 0.16) but this is a good practical estimate which variance is negligible for whole of the protein in a feedstock.

Just an update I have not added any fertilizer to the pond just an occasional drain of water from my bait fish pond and the muck that settles by the drain pipe. I am continuing to feed the trout and the water is taking on a little more of a green tint. The FHM fry are starting to get a little larger big enough to see them swimming around better.

Sounds like your pond is moving in the right direction. The forage pond muck is probably providing a little fertilization.

You might make yourself a secchi disk and keep some reading/date records. If your RBT are happy with your full annual cycle, then don't change a thing. If you need a little more fertilization next year, then you can add some organic fertilizer and monitor another annual cycle.

Good luck, and have fun with your rainbows this year!

Sounds like a plan I will do that. I have some pallet structures in the pond but I also placed some two inch pvc pipe in the shallower water by my deck it has been fun watching the FHM spawn on it they really put on a show