Hey everyone.... my first post, because i have questions regarding a chiller i wanted to construct.

I am normally a PC person.. i used to take fish tanks as a hobby a long time ago, and took a break.

Saw how much technology advanced on the fish tank side.. also saw how much is cross compatiable to PC cooling now, that i decided to build a nice fish tank.

The problem is this.. i have a TEC chiller, able to handle roughly around 320W with holding a D/T of about 20 from hot and cold.

I know most metals are not safe in the fish tank... So i was thinking of using a titanium tube to place inside the tank.
The titanium tube will be on a closed loop fill with antifreeze, and the coolant inside the cold loop will never mix with the aquarium unless the titanium tube ruptures somehow..

Koolance has a stainless steel heat exchanger... i was wondering if stainless steel is a no no? If i could use the stainless steel heat exchanger, i could just take the aqiarum water feed it though one side of the exchanger.

This is the TEC's i will use for the chiller:


I am going to cool the hotside with this guy i had for PC benching.


i was also thinking of tying that guy to my LED setup so i could also watercool the hotside as well as the TEC's... basically get 2 birds with 1 stone...

So which route do you guys feel is the best?
go with the Tiantium tubes... bend them so its a U and then it hangs off the side?

Or go with the stainless steel heat exchanger?



Oh and yes i know getting a new premade chiller will be cheaper.. but.. i have all the parts already which are sitting unused.. i was thinking i could do something fun since i love moding...

Also i have a temp control on the TEC unit... what range of cooling would u guys recommend for the TEC's to shut off? im trying to figure that out as well..


thank you for your time.

ummm so no one knows if i should use titanium or stainless? :\

cuz i cant use regular tubing... tubing by nature is naturally porus... so if i had antifreeze in the cool side, it would most likely leech into the system.

Hi Naekuh,

I would think both Titanium and SS are safe to use in/for fish tanks.

That said, you might have better luck with responses on a reef forum, where chillin' is of higher importance than here with our lower wattage planted tanks.

And even though I am a planted tank AND computer person, I have no real good clue on what you are trying to do or what it is you are working with. Your computer looks really cool though! I am sure someone could mod it into a fancy canister filter for some ultimate crossoverability.

thanks for your reply..

the reason for a chiller in a planted tank is because the tank is small.
I noticed during a hot spike, i would get too high of a flucuation in temperature because of the lack of water vol.

Im literally playing with around 29 gallons.


OK... so in a nutshell in what i am doing.

TEC's have the ability to move heat from one side to the other at the cost of electricity.

in that block with barbs... one side will super cool coolant, while the other heats it up, because ur moving heat from one side to the other.

The cold side as we refer to them in TEC's will be in contact with coolant.
The Hot side will be watercooled via radiator on a closed loop.

What i need is the cold side to get in contact with the tank without mixing the coolant.

P.E tubing is naturally porus... it will leech outside its enviorment, which is why i just cant run a lot of tubing inside a sump or the tank.

The tubing would need to be made of metal and not porus, which is why i was thinking of taking a titanium pipe.. and bending it so its a U at the bottom, and then hangs over the side.


The koolance heat exchanger would make my life easier because i dont need to worry about the titanium tubing... and i could run the exchanger from my canister as the outport.


I just heard a lot of bad things about stainless steel even in the fish tank.
Just wondering if any of you guys had a chance to use it b4 i end up killing my entire tank.

Stainless should be fine. Lots of people use stainless steel mesh to make prefilters in shrimp tanks with no problems at all. Best of luck, keep us updated.

Wasserpest, he's using a PC liquid cooling system to chill an aquarium. The concerns are that the heat exchanger in the tank not leach anything from the metal and that the coolant in the system not leak into the tank.

Stainless is fine.

I looked into doing this myself but settled on a couple bags of ice to get me through the hottest days of summer.

The main component is also know as a "peltier cooler" (or T.E.C.). The huge thing to remember is that 'energy is neither created nor destroyed, only transferred." (the law of conservation of energy)

For this application, that means if you take 1000 BTU's out of your aquarium water, you have to "put it somewhere": Either a heat sink w/ fan and transfer the 1000 BTU's of energy to the air, or the other option is to use a heat exchanger to put the heat into another fluid.

Without a heatsink the peltier plate will overheat and burnout; likely it will smoke your power supply too.

And yes grade 304 or 316 stainless should be fine for the aquarium. I have a 304 stainless steel rod stuck in my tank to bleed any stray voltage to ground.

how hot is your tank getting? we see talk about coolers/chillers pop up from time to time

but most of our fauna can handle a spike...jus not prolonged exposure

ive seen it spike up to 87F.

The tank is in a room which can get hot during a hot day, and with my location, hot days tend to come out a lot.

My Finnex heater has a Titanium tube.

I'm just wondering like why cooling is more expensive than heater?

its easily to generate heat than it is to remove it

lol...

because in order go below ambient, you need to put a tremendous amount of work into the system.

This is where the term CoP relates to.

And yes it takes a rediculous amount of energy to move heat...

example.. if a tec is rated at 60W, that means typically @ 12V it will pull 60W of heat from one side and move it to the other.
then the hotside you will get 60W (tec itself) + another X-Watts moved...

so the hotside on a tec can potentially get to 120W just on the hotside.

now if ur pulling 60W on a 60W tec, your doing something wrong tho... because ur close in killing that tec if u add anymore heat..
As the heat will just pile and pile and get hotter and hotter because not enough heat is being moved.