Hot water heater to heat massive tanks?

[white specter crayfish]

i have heard people say they use their hot water heater to heat their tanks, but how would this work? So I get the hot water goes into a coil in a sump or your aquarium and back in, but I have a few concerns. First, wouldn’t there be a leak somewhere, secondly, wouldn’t that be very dangerous messing with your hot water heater, third, wouldn’t pipes and stuff in your tank or sump be an issue, and fourth, how would it be controlled. I’m looking at a few thousand gallons mind you, I also heard you can put a single heater in a sump and it will heat your whole tank, but I think you’d need a very large heater, probably several thousand watts to actually heat it (My dad said you can put a heater in your sump and it will heat your entire tank, no matter how small your heater is which I think is simply not true). I would love to get a large pond/ tank (it’d have to be really big and an aquarium will cost a hell of a lot of money) to get some sort of temensis and an Arowana, if that doesn’t work I suppose several large tanks would work, like a 200-300 gallon plywood aquarium

 

[Yulli]

Lets start with the easiest and shortest first. A single heater in sump will heat the entire tank, this is true no matter how small. The key thing to remember though is that your tank loses heat, and the more surface area of the tank the quicker it will lose heat. In theory if you insulated a tank and pumped in oxygen then a 50w heater will bring a 300G system up to target temp and maintain it, in practice though this is impossible. Generally target 3-5w per gallon, although this is somewhat flexible especially on larger systems with in sump pumps as they generate a good portion of the heat needed to warm water.

Onto your questions concerning using a water heater. As you have seen the idea is that you create a closed loop with a coil that you pump hot water through. The coil is placed in the sump and the radiated heat warms the tank. As to if their are leaks or not, the answer is no, IF DONE PROPERLY. Is it dangerous, somewhat but not exactly, any guide to accomplishing this starts by splitting the release valve, it also does not affect the emergency pressure release nor any additional pressure sensors the tank may have. Since you will most likely be using PEX (plastic plumbing product) the only issue is sight, although if you used copper you may have issues with leaching. How to control, one of the steps in any of the guides will be to add a circulation pump, in this case what will happen is that the circulation pump is plugged into a temp controller, which has a temp probe which is inserted into the tank. The idea is that the controller will turn off or on based on temperature of the water around the probe, this will stop the movement of hot water through the coil. In case you are wondering the hot water in the pipes will still be warm when the controller turns off, so even after it turns off the circulation pump it will heat the tank, same in reverse for turning on, it will not heat immediately and will most likely lose some heat prior to it warming as the "cold" water flows out of the coil.

My suggestion though with any aquarium you set up will be to ensure that water changes are the easiest possible. If they are easy you will do them, if you keep the schedule you keep the fish healthy.

 

[skjl47]

(My dad said you can put a heater in your sump and it will heat your entire tank, no matter how small your heater is which I think is simply not true).

Hello; It will depend on the rate of heat loss from the tank.

A single heater in sump will heat the entire tank, this is true no matter how small. The key thing to remember though is that your tank loses heat, and the more surface area of the tank the quicker it will lose heat.

Hello; This answer. A small heater may not keep up with the heat loss much the same as in any tank. If the tank loses too much heat then the heater has to be more powerful to keep up.

 

[white specter crayfish]

Ok thanks for the reply guys, I thought it would be dangerous messing with your hot water heater, but this sounds like a better idea than having several heaters in one tank. How would I heat several tanks with this system though? I would like to have probably 20 or so tanks. I'd like a gourami tank, a discus tank, a malawi tank, a peacock cichlid tank, a tanganyika tank, a fahaka puffer tank, a green terror, a dovii cichlid, some community tanks, a ripsaw catfish, tememsis, a tetra tank, a piranha tank, an arowana tank, a gar tank, and some bichirs. I know this is a lot and most all of them need a heater. Sounds like my best bet to save money would be to have plywood aquariums

 

[skjl47]

be dangerous messing with your hot water heater,

Hello; Not so much dangerous to my thinking as requiring some plumbing skills and a bit of expense. A hot water heater is essentially a large tank with some high resistance heating units if electric or natural gas burners if gas. The heater can have full city water pressure in the pipes which I have seen well over 100 pounds per square inch at times.
Two things can be done to limit any physical risk. One is to plumb a pressure reducing valve into the system. I put one in the ground in my system near the water company meter. I keep my total pressure at around 45 psi.
The other is to keep the temperature adjusted down to around 120 degrees F or a bit lower. I have mine set so I can shower with only the hot water turned on. I do not have to mix any cold with it. This also saves on the overall bill as the heater only has to maintain a lower temp 24/7.

I know this is a lot and most all of them need a heater. Sounds like my best bet to save money would be to have plywood aquariums

hello; I do not follow the logic here. Never had a plywood tank so bear that in mind. To my thinking it is the mass of the water involved more than the tank material. To maintain a mass of water at a higher temperature than the ambient air is the challenge. If the desired tank temp is 80 F and the air is 70 F then a heater system has to keep up with the tank heat loss to the air.
Example all my heaters are unplugged right now as it is summer here so the tank are often a bit warm. During the winter tho I have to run heaters to keep the tanks warm.

Any tank, plywood or glass, can be insulated on the outside which can reduce heat loss a lot.

From the description you give it may be more cost efficient to keep the room the tanks are in at or close to the desired temp. You will have a lot of water to keep that list of fish. A super insulated fish room might be cheaper to heat than running a lot of heaters.
Of course you then will have essentially a high humidity sauna and will have to take steps to deal with mold. Tight fitting top covers can help reduce evaporation. I run a small dehumidifier during the winter months to deal with the extra humidity in my current house.

 

[white specter crayfish]

Hello; Not so much dangerous to my thinking as requiring some plumbing skills and a bit of expense. A hot water heater is essentially a large tank with some high resistance heating units if electric or natural gas burners if gas. The heater can have full city water pressure in the pipes which I have seen well over 100 pounds per square inch at times.
Two things can be done to limit any physical risk. One is to plumb a pressure reducing valve into the system. I put one in the ground in my system near the water company meter. I keep my total pressure at around 45 psi.
The other is to keep the temperature adjusted down to around 120 degrees F or a bit lower. I have mine set so I can shower with only the hot water turned on. I do not have to mix any cold with it. This also saves on the overall bill as the heater only has to maintain a lower temp 24/7.


hello; I do not follow the logic here. Never had a plywood tank so bear that in mind. To my thinking it is the mass of the water involved more than the tank material. To maintain a mass of water at a higher temperature than the ambient air is the challenge. If the desired tank temp is 80 F and the air is 70 F then a heater system has to keep up with the tank heat loss to the air.
Example all my heaters are unplugged right now as it is summer here so the tank are often a bit warm. During the winter tho I have to run heaters to keep the tanks warm.

Any tank, plywood or glass, can be insulated on the outside which can reduce heat loss a lot.

From the description you give it may be more cost efficient to keep the room the tanks are in at or close to the desired temp. You will have a lot of water to keep that list of fish. A super insulated fish room might be cheaper to heat than running a lot of heaters.
Of course you then will have essentially a high humidity sauna and will have to take steps to deal with mold. Tight fitting top covers can help reduce evaporation. I run a small dehumidifier during the winter months to deal with the extra humidity in my current house.

Ok thanks, I meant using a plywood aquarium because they're cheaper TO MAKE, getting several 300-600 gallon tanks would be expensive, but making a bunch of plywood tanks would be a lot cheaper, now to heat all of it instead of using a hot water heater you can heat just the room, is there a special way to heat just that room or would you just get a small portable heater? I think that would be better because most of the fish do need a heater, except for an axolotl tank and some community fish I'd like to get but they can go in my main house (I was think with a large amount of water putting it in a garage, though if I heat the room I suppose a basement could work too), as you said mold would become an issue so you'd need a dehumidifier, I'd also probably want a humidity gauge and a way to open up some sort of window to deal with humidity too. Thank you guys for all the help, I know I may be 14, I know I might be asking a lot of dumb questions, I know I might not be experienced but I'm glad you guys are willing to help me learn, I started with fish a year ago for my 14th birthday and I'll be 15 in a month. I have run into great people in the fish hobby and some others (like one lfs owner) who are not so nice, but it's great to see people who love fish and want to help others in the fish hobby.

 

[skjl47]

is there a special way to heat just that room or would you just get a small portable heater?

Hello; lets do the fantasy bit and say you get all the fish you wish for. To do it right will take a number of large tanks and that means a lot of water. The room will have to be large enough so you can have the tanks and some room to work around them. I do not think the small portable heater will keep up and if it did the power costs will likely be high. You will need something robust.

a way to open up some sort of window to deal with humidity too

Hello; Works in the summer but not in the winter.

Hello; Another thing to consider is the weight of several large tanks. In abasement on a thick slab likely will be OK if the slab is thick enough.

 

[white specter crayfish]

Hello; lets do the fantasy bit and say you get all the fish you wish for. To do it right will take a number of large tanks and that means a lot of water. The room will have to be large enough so you can have the tanks and some room to work around them. I do not think the small portable heater will keep up and if it did the power costs will likely be high. You will need something robust.


Hello; Works in the summer but not in the winter.

Hello; Another thing to consider is the weight of several large tanks. In abasement on a thick slab likely will be OK if the slab is thick enough.

And if the slab isn't thick enough?

I guess I'll just stick with a dovii, axolotls, and fahaka puffer then that would be more realistic to begin with and at that point might as well he the individual tanks

 

[skjl47]

And if the slab isn't thick enough?

Hello; most slabs will be thick enough I guess but there is no guarantee until it is checked out. Not thick enough and the weight will cause damage.

 

[white specter crayfish]

Hello; most slabs will be thick enough I guess but there is no guarantee until it is checked out. Not thick enough and the weight will cause damage.

Ok, I guess I'll just do a dovii, fahaka puffer, axolotls, and maybe some other small tanks