Economy of fish

[Brian Rodgers]

Good morning
We munched another trout last night, super yummy. I wasn't caught, just like the earlier fish; it was dead on the bottom. We watch our fish very closely so we're fairly certain it was fresh. It was big and beautiful.
Here is our observations at this point after 9 months of fish keeping.
We began with 47 3 inch (7.63cm) Brook Trout fingerlings back in October of 2015. Last night's meal was 15 inches (38.5 cm) long head to tail. I didn't weigh it, but it was an oversize meal for two on the protein side.
There have been only a couple losses of trout over the season.
I haven't counted them, so I'll guess there are 40 big fish left.
2600 gallon pond
Laguna 4000
Fountain and Waterfall Pump Kit
Maximum Flow Rate: 2000 US GPH
Maximum Pond Volume: 4000 U.S. gal
four small media grow beds totalling ~1450 liters
4 - 3 to 4 foot long media filled strawberry towers
30 gallon RFF 50 gallon Caldness filled MBBF
We cleaned the FT a couple weeks ago, draining it all the way down to about a meter deep.
While netting this fish off the bottom an unbelievable amount of fish poo was stirred up.
We'll start harvesting fish soon. I am curious just the same if there is an alternative to a mass harvest?
I haven't read of people keeping food fish past a season, I thought the reason was more because of the difficulties of keeping water temperature in cold water species comfort zone.
Now I'm seeing another issue: Massive amounts of fish waste.
I thought I'd buy a bigger pump.
I seek advice, have we reached an economy of fish size for our system?
I may still buy the next size up in pump. It seems like I'd have to upsize everything to keep the monsters growing toward my goal of 20 inches (50 cm) and a kilogram in weight.
We don't want our fish living in fish waste filled water.

 

[xraycer]

Are you, or have you considered using hydroponics as a means for water filtration and growing edible veggies?

 

[Brian Rodgers]

Yes, this is an aquaponics as well as a filtered system

 

[skjl47]

Hello; Not sure I understand the situation of the pond. Does the pond have a constant inflow and outflow? A friend has a pond on his property fed by a small year round stream and is constantly being flushed. It will still silt up over time.

If not, is it basically like an aquarium on a very large scale? If so you should have the same issues as any closed body of water. I may be wrong about this but seem to recall that the commercial hatcheries do drain and clean out their ponds from time to time.

 

[ragin_cajun]

Sounds like you need a big gravel vac? And a water change? Make a gravel vac out of 2 inch PVC and a real big hose, start a siphon, and vacuum the bottom.

What do you feed them? And why eat the dead fish? If it was me, I'd net one out that was still swimming. Sounds like you have plenty.

 

[Brian Rodgers]

Yes this is a closed system. 2600 gallon pond in a fish house / greenhouse.

 

[carbene]

those trouts look delicious

 

[Lepisosteus]

Talk to some fish farms. Shoot kinmount fish farms an email or call, talk to Karl. Great guy willing to help and grow the aquaculture hobby. Expert in trout. Water changes are still needed and should be increased. Harvesting yearly to my knowledge is in order to maintain an economic profit. After 2 years growth is to slow and results are not much different then after one year

 

[Lepisosteus]

Awesome set up, would love to do something like that

 

[Hoplo]

Cool looking set up.
As for the pond silting up if you can get a pump in there that will pick the dirt off of the bottom, and pump it to a mechanical filter of some description (sand pool filter, some filter, etc) means you can manually remove the waste easily.

Also the more plants you have growing in the water, the better the water quality will be as it removes the waste, and if you are growing edible plants it means that you will get more produce out of every bit of food that you put in. (I am a fan of value)

As for harvesting all at once, what is stopping you from just fishing out one fish at a time whenever you want to eat one?