DIY inline heater for 800-1000 gallon aquarium.

Rgreenfield3

Feeder Fish
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Jul 20, 2017
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Alright guys so I'm going to be building a 8'*4'*4' tank here within the next couple months in my basement. I've already gotten the glass size picked out thanks to you and the blueprints are done. I am going to be having a custom overflow system out the back leading to a 55 gallon drum which will be filled with different filter media. Once the water passes through that and is clean I will run out the side from a pvc pipe to a UV sterilizer. Once it passes freely throylugh there it will then end up going to an online heater which I will be building and then end up draining into 30 gallon drum with a submersible pump that will pump the water back into the tank.

My question here is what size heating element would I use to heat the water to about 80 degrees? Does the 5 watts per gallon rule still apply to inline heaters? It will be running from a thermostat that will be reading temps within the tank to keep the heater efficient and reliable. For a living I am an industrial maintenance technician in a forging plant so I'm pretty familiar with mechanics, electrical, pneumatics, and plumbing. Once I start the build I'll be sure to keep a log of everything I do and the materials I use and I'll be posting my own build here for anyone who is interested. Any tips or recommendations let me know. Thanks for the help previously and thanks for the help now guys.
 

Thomas18

Jack Dempsey
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Mar 1, 2017
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Have a look the the design that The King of Diy used for his diy inline heater. You will probably need to have multiple heaters rather then one. which is not really ideal for inline heaters. it is a good idea but it would probably be easier to have them in the 3o gallon drum with the pump the water movement from the pump drawing water will make it so that the water is heated evenly.
 
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twentyleagues

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Yes that would be best. And put your thermostat in the "chamber" right before the heater so its the farthest away from the heat source (in terms of flow). When I had my salt set up I cant remember the name of the thermostatic pump I used to cycle water from my hotwater tank to my sump through a coil of pex and back to the water heater. I had it plugged into my reefkeeper for safety but it worked great, and I had instant hot water at any tap in the house.
 

Oompa Loompa

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Two ideas here that shine for heating large indoor tanks.

First - titanium heaters. You could run a single 4000-5000 watt heater and probably be fine. Joey (King of DIY) has a good video on an inline heater setup.

Second - go with VLDesign's idea of using a radiant heater system.
Basically - there's a valve on the main hot water pipe, leading it to a circulation pump, which runs it through a big coil of tubing located in the sump. The coils will get hot, which will heat the surrounding water. Then the water is fed back into the water heater, and it can be used elsewhere in the house - sinks, washing machine, shower, etc.
You'd need some kind of regulator, to make sure you don't overheat your tank. But this would probably be a pretty efficient system to use.

Drew
 

Drstrangelove

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A couple things:

1) I suggest you have more than one heater. One heater that goes = disaster; one heater that gets stuck on "on" = disaster.

With two heaters (or better yet 3), assuming neither is strong enough by itself to over heat the tank, a failure in one to heat means the tank is heated, but not quite high enough; otoh, if one gets stuck on "on", the tank temp can't reach critical.

Of course. I agree with the use of a thermostat that will turn off the power to the heater if the proper temp is reached. But a thermostat won't stop a single heater from breaking.

2) To calculate with any accuracy how many watts in heat you need to add we would need:

a) your ambient (room temp)
b) whether your tank has a top
c) what your tank is made of
d) what your tank has under it (air, wood, iron, concrete)
e) what insulation your tank has on it (if any)
 
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twentyleagues

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Two ideas here that shine for heating large indoor tanks.

First - titanium heaters. You could run a single 4000-5000 watt heater and probably be fine. Joey (King of DIY) has a good video on an inline heater setup.

Second - go with VLDesign's idea of using a radiant heater system.
Basically - there's a valve on the main hot water pipe, leading it to a circulation pump, which runs it through a big coil of tubing located in the sump. The coils will get hot, which will heat the surrounding water. Then the water is fed back into the water heater, and it can be used elsewhere in the house - sinks, washing machine, shower, etc.
You'd need some kind of regulator, to make sure you don't overheat your tank. But this would probably be a pretty efficient system to use.

Drew
Wow that radiant heater is a great idea! Vldesigns came up with that! Man I bet thatd work great.........
 
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Rgreenfield3

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A couple things:

1) I suggest you have more than one heater. One heater that goes = disaster; one heater that gets stuck on "on" = disaster.

With two heaters (or better yet 3), assuming neither is strong enough by itself to over heat the tank, a failure in one to heat means the tank is heated, but not quite high enough; otoh, if one gets stuck on "on", the tank temp can't reach critical.

Of course. I agree with the use of a thermostat that will turn off the power to the heater if the proper temp is reached. But a thermostat won't stop a single heater from breaking.

2) To calculate with any accuracy how many watts in heat you need to add we would need:

a) your ambient (room temp)
b) whether your tank has a top
c) what your tank is made of
d) what your tank has under it (air, wood, iron, concrete)
e) what insulation your tank has on it (if any)
My room temp will be more than likely 70-75f in the winter and probably around 65-70 summer. I just bought a new house and will be finishing the basement. I'm upgrading the furnace this weekend to be adequate for heating and cooling my home since the previous owner did a hack job on it. During the times of the year where my AC will be on my vents will be shut in the basement where the tank will be. I'll be finishing the basement after the tank is built and put a wall up around the front of the tank to make the window built in the wall. The back room where the tank will be accessed as well as the filtration system will all be withing 3-4 feet from my furnace and water heater.

The tank itself is a going to be a plywood build with r-15 insulation in the walls with more plywood over it and drywall on the front. I will probably use r-19 under the tank inside the stand.

I will also be making some custom lids out of either Plexiglas or greenhouse plastic glass. Not sure yet.
 

Rgreenfield3

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When I meant I was thinking about building an inline heater I was kind of thinking about using actual heating elements like in this picture with a thermostat to turn it on and off and powered either by 2 or 110v. Is there any other ways that I could hear this thing without majorly breaking my bank account on the utility bill? The 55 gallon drums I'll be filtering the water in will also have insulation wrapped around it with lids and the pic pipes will also be wrapped.

Screenshot_20170912-200820.png
 

Drstrangelove

Potamotrygon
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I assumed insulation on all sides except the front, and assumed an average of 150 watts of heat added by other equipment.

If you are losing zero gallons in evaporation per week, you will need 482 watts to keep the tank at 80 when the room is 65.

If you are losing 50 gallons in evaporation per week, you will need 1,241 watts to keep the tank at 80 when the room is 65.

So evaporation is the remaining key variable. The number is of course not going to be zero gallons. But at 20 gallons per week (i.e., 2%), which I think is very low, you'll need 786 watts.

You will be somewhere in between those numbers, but otherwise other areas (the 2 drums) are open. (If you had a reef tank and fans intentionally blowing over the tank, you'd lose about 10% per week, or 100 gallons.) 1,000 watts looks like a reasonably number with a little cushion if you keep the evaporation down.

Btw, assuming that in both cases, you have a tight fitting top, changing the top to a glass top (not wood) will increase the heat requirements by around 250 watts. (Of course, an ill-fitting top will increase evaporation.) But wood, acrylic and pvc all have a similar advantage over glass in terms of reducing heat loss.
 
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twentyleagues

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So it's been 5-6 years since I had a salt water system.....it was around 2000g all together nothing was covered except in the two tanks upstairs, they had canopies. I used 4 800w finex titanium heat rods run off my reefkeeper. Kept system at 80. I was also running a butt load of t5ho for coral so those helped with heat and the huge electric bill. Around $400 a month. Also had 3 very large pumps running. I found a thread on one of the reefing sites about running a coil of pex in your sump that was attached to your water heater. So I did it. Worked great my final "chamber" that the return pump was attached to was a 100g Rubber maid stock tank. I got a 6' x 18" restaurant cutting board and cut it in half and drilled 3/4" holes up both sides of both pieces and threaded the pex through the holes and placed it in the sump, I believe I used 100' of pex. Hooked it to my plumbing the inlet can be any hotwater pipe the outlet has to go to the drain on the water heater I hooked the circulation pump to my reef keeper and bam! Cheap heat. You have to account for heat creep unlike an electric heater that shuts off and is cool almost instantly the hot water is still in the pex. My creep was about 2 degrees so you'll need to set your thermostat accordingly. My electric bill dropped around $80 a month gas went up $15ish. Oh yeah this isn't going to be really effecient if you don't have gas hot water. Lol. It could have been more it wasn't less but I don't remember everything 100% like I said I stopped being addicted to salt 6 years ago and this was 3 years before that. So yea HI I'm twentyleagues and I'm a recovered salt addict.
 
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