heating fish tank water

[Del Roach]

Can someone tell me the most efficient way to heat my fish tank water?  Thanks  Doc

[Vlad Jovanovic]

Yeah, and then there's that ... Cash seems to be putting the breaks on my heating needs as well. I've come up with a sort of plan for running fish-less or mostly fish-less, for at least this winter, if need be...but still obviously need to heat the water somewhat for the plants and bacteria...and phosphorous uptake by plants as well has proven real temperature dependent in the little experiments I've run . I'll probably keep a couple dozen token fish in the system for 'experimental' purposes just to see what kind of temps they can take and all, nothing I plan on adding in the way of plant essential elements should be detrimental or at least not lethal to the fish. That's my thinking anyway...

Plants I don't mind killing or damaging in order to experiment a bit and what works and what doesn't and figure out why, and I've learned a lot from theses 4 or 5 different little systems I've been running...but I kinda feel weird about it when it comes to the fish. Guess i'd make a crappy Nazi doctor...

[Jim Fisk]

My 2 cents on woodboilers. The 5000.00 models are the biggest waste of wood I have ever seen and have chimney fires about once a week (I owned a Central Boiler Classic) and I have been heating with wood for 50 years. The wood gasification boilers which are clean and efficient start around 10,000.00!!!! Where's the pay back on that. You can put a single loop in and out of just about any woodstove  and place a hw tank next to it and have all the hot water you could ever use. Make sure you know what you are doing tho safety wise. Damn near blew one up about 35 yrs ago. My woodstove plans are on Ebay and it even has an oven and cook top as well as heating water. No UL app so use it in the cabin or gh or shop. Not in your insured house.

[Joe Bifano]

Talking about that Jim I built a double 55 gallon wood stove and put in a stainless steel heat exchanger. It worked great for about a month then I started getting creosote build ups and had to stop and clean it up real good. My problem was that ai had a 90 to the wall then another 90 up so I was not getting a good draft. I was able to get great heat temps in the water storage tank but never made a heat exchanger for my propane system.

I just purchased a inline fan for creating a way better draft. Once I get this up and running hopefully I will have no more draft problems and smoke issues when I open the door to load wood. If this works I will build my heat exchanger and set it up to my propane system. I have it setup so there is a 3 speed pump on the heat exchanger in the stove so it can go through the stove pretty fast and still get a decent amount of heat. I have it on a battery backup so if the power goes out the water in the stove will not come to a boil and like you said blow something up.

So 10K for a wood gasification boiler is the way to go if I need more.  That is a lot to pay for. Maybe my 55 gallon system will work and I will never get it and save that.

[Jim Fisk]

Hey Joe, that is the problem with most barrel stoves. Mine is a gasification design, auto thermostat, fire brick lined clean burning gem. Built the first ones in the early 70's. It is a single barrel with a 30gal on top and a 5gal in that for the oven. That's me 40yrs ago loading it up for the newspaper. The papers and tv news did stories on it. Lucky the ins co didn't cancel us with all the publicity! Made up the plans before computers existed. Now in pdf. Also that is a 2' x 14" elm log. Once you had coals it would burn a log like that.

The hot water tank sat to the right and not having forums in those days and no one to ask we learned most things the hard way. I got a hell of a deal on 3/4" soft copper tubing and proceeded to place about 8 turns in the 30 gal drum. By Sunday morning it had made all the hot water it could hold and started making steam. The 40 gal hw tank started blowing off and dancing. My wife and I were still in bed and this horrendous racket started in the next room. Well I knew instantly what was happening so I jumped out of bed stark naked ran out there and closed the air intake, grabbed a pot of water, opened the wood door and threw the water in to cool it down quick. I then threw the back door wide open to let out the smoke and steam. My sister-in-law's 12 yr old female friend was just about to knock on the door when it flew open and here I was stark naked, long red hair standing on end, surrounded by smoke and steam. Never saw her around the farm again after that. Don't know why One loop in and out just above the fire brick was the "final answer" Copper sweat is fine as it is always full of water so the solder can't melt. And it is close to the coals so it does not creosote up.

[Joe Bifano]

Hey Jim were did you put the heat exchanger then for your water heat? What are you building now in the plans? I love it that you did this that long ago.

[Jim Fisk]

This stove was not used for hydronic heat. This is for domestic hw and hot air heat but can certainly be modified for hyd heat with more tubes and a circ pump, etc.. I simply run about 2' of 3/4" copper pipe in and out thru a couple of holes in the rear of the 55gal drum and located just above the fire brick.. You can see them better in this drawing:

Located in the fire box they stay clean and are placed to absorb more infrared heat during hot coals stage. As you can see the plans were all hand written and scanned into the computer many years later. I've gotten feedback on them from as far away as India. The cast iron 4" sewer pipe is where the wood gas is burned off during the gasification period. Hot coals are pushed to the back during reloading as opposed to forward like in most wood stoves as that . (spell ck hates that word "gasification" which shows you just how far ahead of the curve this concept was:-)

You could easily double or triple the tube area if you use a circ pump. I was depending soley upon convection with the hw tank next to it and we never ran out of hw in the winter. In summer we turned the electric elements back on. You want to tap the hw tank at the top outlet and the bottom drain to facilitate convection. If you are heating the AP sump water which is below grade you could have an intermediate tank for convection and send the pump bypass thru that or the like. Best way is to run the wood stove hot and heat up a mass of water and let the stove burn out between firings.

This shot shows the firebrick best:

Hope this helps. I plan to build one for the gh this Fall as I hate cutting holes in an expensive store bought stove for the pipes. Drums are great and easy to work with. Now I weld everything with my Miller mig that I have had for over 30 yrs. Much faster than the nut and bolt construction back then. With the the fire brick the stove lasts forever. I may use the thinner ones to save wood space. Probably ss tubing rather than copper although I have a number of ss heat exchangers which would keep the copper away from the system.

Joe Bifano said:

Hey Jim were did you put the heat exchanger then for your water heat? What are you building now in the plans? I love it that you did this that long ago.

[Jim Fisk]

Sylvia needs to allow a little more time for editing, I have lost my work on numerous occasions now because of the time limit. Correction in CAPS below.

The cast iron 4" sewer pipe is where the wood gas is burned off during the gasification period. Hot coals are pushed to the back during reloading as opposed to forward like in most wood stoves as that IS WHERE THE REAL BURN TAKES PLACE. (spell ck hates that word "gasification" which shows you just how far ahead of the curve this concept was:-)

[Fred Gill]

Rocket mass heater

[Joe Bifano]

Hi Fred I have read a lot about rocket mass heaters but have some questions.

Do you have one?

How can they help heat a 2000 sq ft greenhouse?

Do they have to have a large Cobb area for heat exchange?

How many BTU's will these put out?

Can they be used to heat the water?

I would like to see and hear about someone you is using it now to heat a large greenhouse and use it to heat their water.

[Japan Aquaponics - アクアポニックス 日本]

Hey Joe,

Out of curiosity, how is this set this up in your system?

1.  Fish Tank - Foam - Aluminium... or

2. Fish Tank - Aluminium - Foam

Joe Bifano said:

There are a couple of things you can do. My tanks are in the ground and I am in Colorado so it gets cold. I have them insulated with 2" foam and a Aluminum barrier for a total of R21.  I then have a pex setup all around the sides and bottom of the tank that comes from a hot water heater.  I see it on for about an hour per night. I keep it at 70 and I am having 40 degree nights already. The other thing I am trying is a solar panel were my raft water is pumped to it and comes back about 3 to 4 degrees higher than it is. This setup works at keeping it over 73 and then it goes down at night to under 70 and my pex system comes on for just a few minutes. I think the key to having a Solar panel is making sure that the fish waters do not get hot via the flow. My flow is fast so I only get a few degrees when it passes rather than having it slow and the temps get to high and do something to the fish nutrients. I made it with CPVC with no copper and have it set almost vertical as a drain-back system for the winter and so it does not get to hot if it stagnates at all.

[Joe Bifano]

If you look at the Milwaukee company growing power they have a hole in the ground the size of the fish tank. That is what I did. I have the framing in the hole with the 2" foam on the outside of the framing. Then on the inside of the framing I used 3/8" plywood. Then I have the aluminum double bubble  r15 foil attached to the plywood.  The attach the PEX through the foil into the plywood. Then I put over all of this my 2 liners. The foam is directly against the earth giving me a 7.5 R value. then the framing, then the plywood, then the r15 foil, then the PEX. The PEX has all of this to insulate it against the earth. The earth in mu location is at 55 degrees so I do not have to warm the water all that much becasue the earth has already insulated it. If the tank were above ground you loose that earth insulation. I insulated again because I wanted to not loos that much to the earth. I also cover the tank with the same foil so I get an r15 top cover. It works great with a HVAC setup with zone valves.

If you have more questions let me know.

[Japan Aquaponics - アクアポニックス 日本]

Thanks Joe, that sounds like what I thought, but am always curious to see how people do it, and the results they have found.  We are talking to a "straw bale builder" guy at the moment and we are going to look at building a straw-bale and cob structure around the tanks to see how good of an insulation that provides.  Gotta keep experimenting!

Joe Bifano said:

If you look at the Milwaukee company growing power they have a hole in the ground the size of the fish tank. That is what I did. I have the framing in the hole with the 2" foam on the outside of the framing. Then on the inside of the framing I used 3/8" plywood. Then I have the aluminum double bubble  r15 foil attached to the plywood.  The attach the PEX through the foil into the plywood. Then I put over all of this my 2 liners. The foam is directly against the earth giving me a 7.5 R value. then the framing, then the plywood, then the r15 foil, then the PEX. The PEX has all of this to insulate it against the earth. The earth in mu location is at 55 degrees so I do not have to warm the water all that much becasue the earth has already insulated it. If the tank were above ground you loose that earth insulation. I insulated again because I wanted to not loos that much to the earth. I also cover the tank with the same foil so I get an r15 top cover. It works great with a HVAC setup with zone valves.

If you have more questions let me know.