Pond Boss Forums STOCKING A NEW POND Creating the food chain Mass of edible periphyton

2 yrs away from pushing dirt for 2 acre coldwater pond in foothills of Rocky Mountains. Wondering if any of you have tried anything like this.....

Essentially masses of dense (but not so dense that air/water could not flow through) organic material, such as hay, that functions as a substrate for a large amount of periphyton and after time the substrate itself could be consumed. The system would have to 1) produce a surface area of an order of magnitude as to approach that of synthetic floating islands 2) be populated by herbivorous organisms, such as crawfish and/or tilapia 3) be suspended off the bottom/away from any anoxic areas and 4) ideally be coupled with aeration (which may make #3 less relevant.)

The goals of this would be 1) to filter the water column of nitrogen, phosphorus, and suspended clay 2) to "harvest" phytoplankton/incorporate into the periphyton community 3) to add to the primary productivity of the pond. These goals would vary significantly in relative importance depending on specific water body.

I would imagine that a Southerner in a state with permissive laws about what can be stocked may be able to do well with a crawfish, tilapia, freshwater shrimp polyculture. In addition, it would be interesting to see what the omega 6/3 ratio of such tilapia without a soybean based diet would be.

May try to raise some warmwater species in a cordoned off (solar heated/doubling as swimming area?) part of our pond 5200 feet up in Idaho, but for the most part, I'm hoping for a clearwater, productive pond with thick crawfish, insects, and therefore fat trout.

WoodyL - Are you aware of this informative book dealing with periphyton and fish production?
http://www.amazon.com/Periphyton-Ecology...+and+management

Thank you for the tip - I have seen it and read several of Dr Aziz' papers. I have thought about springing for the $150 but was going to wait till I'm a little closer to construction, in case he pumps out a new edition in the meantime

Most of what I've read in what he has published has described experiments that compare an amount of added periphyton that is obviously more than the control arm, (such as plastic netting in shrimp ponds, or sticks at regular intervals in a tilapia pond) but does not seem to be of the order of magnitude such as promoted by those building synthetic floating islands.

And would the added effort/expense of hucking tons of hay in specific (likely elevated off bottom somehow) spots be more worthwhile than a super brush heavy pond with aeration, that doesn't have to be replenished as often? Without being able to stock tilapia other than a small area, would the crayfish/insects/zooplankton/bacteria/fungi be able to process it?

And would stocking some nitrogenous hay (alfalfa, clover) produce any added benefit?

Adding lots of organic materials to a small pond runs the high risk of too much biochemical oxygen demand that degrades the water quality and often the bottom sediments to the point it suppresses the invertebrate production that is the purpose of the producing periphyton.

Bump

What is your preferred species of trout? Also would like to know what you're mean daily temperature is in July.

We are in a restricted cutthroat trout area that I think the only trout species we can stock are that and triploid (sterile) rainbows. I assume other sterile salmonoids would be ok, all female Coho salmon sound intriguing. To better utilize the insect base, I'm hoping for mountain whitefish (pretty decent tasting) and to best use the periphyton layer, mountain suckers. To convert the soft vegetative material, as well as to provide an alternate food source, I'm counting on crayfish.

July can be hot, with daytime temperatures in the 90's, but nighttime temps drop into the 50's. I'm counting on aeration mainly at night, which should help keep temperatures down, as well as keeping the amount of shallow water to a minimum. Someone a mile away raises huge rainbows on feed in 1/4 acre ponds 20 feet deep without aeration.

Bill, I appreciate your highlighting the potential for excessive biological oxygen demand. "Hucking of tons of hay" into some containment system may mainly need to be at ice-off, and rely on a significant mass of brush for the end of the season.

My overall point is I wonder if those benefits demonstrated from increasing amount of periphyton (such as that demonstrated by floating islands) can be achieved with biomass, and if there is sufficient ability of a water system to assimilate it, if there is an advantage (especially early in the season, when weedbeds have not yet built up) to having a significant portion of it be soft biomass such as hay. In contrast to a weedbed, which grows all year and then decomposes in the fall/winter, hay put in a pond in April should be long decomposed by fall

If you aerate, don't use a bottom diffusion system, use a surface agitator. A bottom diffusion system will de-stratify the water, mixing the warm upper water with the lower, cooler water and raise the overall temp of the pond, even with just aerating at night.

Been there, done that with the bottom diffusion system and had the trout die much sooner due to increased water temp than with no aeration.

A client had Golden Rainbow Trout survive into almost 80°F water temps by having both a bottom and a surface agitation system going 24/7. Oxygen levels were at the saturation point.

Was originally considering bottom aeration at 10 feet with 20 feet being max depth with the idea that this could serve as both the summer and winter regimen - do you think this may suffice? Did your client who aerated 24/7 also aerate all year/including spring/fall?

I think it might depend on how much of the pond volume is below the 10' mark....

Yes, he's running the bottom diffusion aeration system 24/7/365. Switching from shallow water diffusers during the winter to deep water diffusers during the late spring/summer/early fall.