Heating fish pond water

[Chris Duke]

I saw a post last night about cooling water in your fish tanks. I thought heating the water in wintertime would be a worthy post as well.

This system could be used to heat very large tanks of water with just a small solar pump in wintertime. I would run the system in a closed loop with a 50/50 mix of water and glycol same as a car radiator and for the same reasons. Just run the tubing on the bottom of your pond and back up to the collectors. Simple. Use a temperature sensor, and a automatic valve to let the water flow until the desired temp is reached.

http://youtu.be/SPt93nX8iwI

[Chris Duke]

Second option, adding a domestic hot water storage tank to the system.

A small solar powered pump could keep the water circulating between the collectors and a water storage tank. This many panels could heat a LARGE water tank. One much larger than in the video. In the water storage tank, you would have coils of tubing that would collect the heat and with another small solar pump, keep it circulating into a potable water storage tank for home use as well as threw a fish pond when needed. Solenoid valves hooked up to a thermostat would make it completely automatic. One would shut off the house hot water storage recirculation, and open the fish tank circulation that way you would only need one additional pump to the closed system circulation pump.

[Phil]

I came across a neat idea for heating the traditional grow beds in my greenhouse with compost and am considering trying to modify it by extending the insulated hose to coil it a few time around the inside top edge of my fish tank after it leaves the growbeds.

I'm wondering if it might be better to just run the hose around the inside channel of the grow bed at heat the water up top before it drains.

My aquaponics setup is in the greenhouse as well, so I think maybe a loop to it and back to the grow beds with a cutoff for summertime would be adviseable.

see the type of system here:  http://www.farmshow.com/view_articles.php?a_id=93

Any thoughts, comments or ideas would be appreciated.  Thanks

[Chris Duke]

Cool. I saw a video where this guy would pile his compost up around the outside walls of the building for winter. He said it kept the need for adding additional heat down quite a bit.

I'm thinking that if your grow beds are fed by gravity from your FT, you could even run the heating tube threw your supply line to heat the incoming water.

[Phil]

Chris...I thought of that but wasn't sure what the temps would be...at 115 F I think too hot for the roots....and then that breaks the closed loop...since the bed drains back into the tank.

That's why I thought maybe a Y connector with a cutoff in the in the insulated line under the traditional growbed, with a loop circulating in the AP grow bed and then back into the system might be the better way.

[Chris Duke]

You could still keep it as a closed loop. Add one tee at either end of your supply line, then fish the tubing down threw one tee and up threw the other one. It would have to be a gravity supply to work, cuz I would have no real idea how to seal plastic fittings in a pressurized pumped supply system. It could probably be done with the use of threaded x slip compression fittings of the correct size.

Water temp could be regulated with a sensor in your FT and a solenoid valve on your closed loop. When the water gets below your set temp, the solenoid would open automatically and when your preset temp is reached, it would close by itself.

[Chris Duke]

When I do get my farm and start doing this on a large scale, I plan on digging down and installing air ducts below the ponds. I plan on housing my main ponds. I'll build a mass heater to get the exhaust gasses flowing under the ponds, and to heat the rooms on really cold winter nights. I'll put a Y in the ducting that operates a solenoid to close off the venting under the tanks at a preset temp. I don't know how that would work though. I may just have to do that one manually each night to keep the pond water from getting too hot. The advantage off a mass heater is that for a long time after the fire goes out, they continue to radiate heat. I saw a couple who made a very small one in their very small green house, and by morning it was up to 90*F under the grow beds from just one small fire set at sundown. I don't think they used enough sand. They said in the video that they ran out and just finished it off with gravel.

Here's an example. http://youtu.be/qtFvdMk3eLM

[Phil]

nice..I like that idea..and I think I even have solenoid laying around my shop..\

I'll have to draw that out.  But actually my grow bed is fed from below..it covers the FT to keep the light out.  then it's a gravity drain back to the FT.  FT does have a lower hose fitting but it sits on the floor.

If I buried the reservoir below ground I might get the needed slope.  I like the idea of piling it up against the sides too..the way the greenhouse is backed up to the house, the space it would be doesn't get direct sunlight at the lower 3-4 feet anyway..the other side faces north and is essentially an herb garden in summer and coldframe in winter..thats the side the tank is on...hmmmm

Thanks.  I love spitballin'..now I have to see what I have parts for...

[Phil]

Yes..I've seen some rough video and done some prototyping with rocketmass heaters.  It's a great thing if you're building from scratch.  I've even got all the materials assembled for one, but I think I"m going to use them for an inside one that vents out my existing corner fireplace.  The mass will be a corner bench/sofa/bed which will cover @ 1/2 the short wall and 1/3 to 1/2 the long wall.

If I'd known about them have put one under the greenhouse before I laid the brick floor.let the brick and sand serve as the mass. 

The compost heater idea came after because I have the perfect space, the access to manure and wood shavings in bulk and all the other materials on hand and it the better "aftermarket" solution since I already laid the brick.  Take very little solar to power the pump if necessary but still power dependent.