I have a 1.25 acre excavated sandpit pond. The average depth is 15ft, with some sections 20ft deep. I am in a low lying area on Maryland's Eastern Shore, and the pond is filled with ground water.

I'm curious about the feasibility of keeping rainbow trout in cages during the summer, utilizing a small pump to pump water from the cold, deep pond bottom into the cage. Could I use a venturi valve, a spray bar or other means to off gas anything bad and oxygenate the water as it enters the cage. I'm guessing there is a magic flow through volume that would provide sufficient cold water to keep the fish alive, yet be slow enough to not completely mix / de-stratify the pond.

Thought?

Brian

One of our Canadian members did what you are proposing. Hopefully he will chime in.

I would think you would need more volume to your pond to pull this off. I am far from an expert though.

Is your pond aerated? If it's not I would install one and put a diffuser in a deep part of the pond. You have to follow the proper start up procedure though. It would be more beneficial then just pumping bottom water up. IMHO

I tried it last year with my Brookies in my ground sourced pond last year and couldn't keep the temperature under control even pumping in 5-8gpm of well water. I had ran the water thru a degasser system which also bumped up the oxygen level and actually decreased water temps but it was still no use unfortunately. I landed up buying a 500 gallon tank and moving them in doors and sure glad I did...I used less water and the growth was amazing!!! Search a few of my older posts and you will see my setup....going even bigger this season

Ryan

Thanks for the Replies everyone.

Ryan, was your first attempt in a cage in the pond? I'm wonder now if I could instead make a small plywood above ground raceway. I could line the raceway with foam insulation board to minimize heat gain. I could also cover a portion of the top with foam board and shade cloth.

it was my first time trying it with the cage. I also ran the well water thru a degasser system prior to entering the cage. I also covered the cage with foam and skirted the sides about 2 feet down into the water. In the end it was no use! I spent less than $500 and had about the best system possible for my Brook Trout for the 3 months they were in the tank in one of my out buildings and growth was amazing! I also was able to use a lot less of my well water/hydro by doing the tank setup and this year I will be adding an even larger pressure tank for my re-circulation system and will cut the hydro bill down even further!

Ryan