# Sharing Chiller



## yxberia (Apr 19, 2005)

Has anyone tried or had an idea on sharing 1 single chiller with many tanks? 

My prototype plan:

1. 2 tanks, A (4 feet) and B (2.5 feet).
2. Tank A is now cooled by a chiller. B is my cooling target.
3. I will extend the OUTLET of the chiller. Connect to a "copper" coil dipped into tank B. 
4. The water is returned to tank A by connecting the outlet of the coil back to tank A. 

I know copper is poisonuos and Titanium is not only expensive but also hard to get here. That's the only problem. 

Any suggestion is welcome.


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## onemyndseye (May 12, 2006)

I think it would probably work but as you stated copper is toxic to many beasties in the aquaria...... problem indeed  .. You might could you brass tubing *shrug*... also, perhaps you could coat the copper tubing with epoxy resin to make it safe....

I would think it would be easier to add an overflow to both tanks and have them share a sump.. then the chiller could operate in the sump and everyone is happy 

A Skimmer box/HOB Overflow/External Overflow/Siphon Box or whichever you what to call it can be purchased online for around 30$ or even made pretty easy...

Heres a couple of DIY Overflow links:
http://www.melevsreef.com/acrylics/overflow.html
http://www.podzilla.us/aquascapeDS/overflow/overflow.html

If mixing water systems is a problem.... you MAY could get away with dividing the sump into 3 water-tight sections.... One on each end for each tank.... and one in the middle for the chiller. If glass was used for the dividers then the cool/cold water in the center compartment should cool the two end compartments.... how much I dunno.... The glass would probably have to be as thin as possible.... so bracing it might be a good idea.

If it worked it would also provide a place to hold and age top-up water to replace evaporated tank water.... add a float valve etc etc to keep the chiller compartment full... maybe a couple pumps and timers to pump a bit of water from the chiller compartment to the other compartment once every few days..... *shrug* just afew ideas 

Take Care,
-Justin
One Mynds Eye


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## yxberia (Apr 19, 2005)

Thanks for the great idea and detail plan. 
About the coating:
Yes, I can apply thing coat onto the outside of the copper tube. But not the inside. Water flowing back to tank A is still contaminated. 

About the DIY overflow:
The heavy overflow may be too risky for glass fish tank with standard thickness. The heat-exchange among those compartments may not be efficient. Both of these plans will still need the right metal.


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## onemyndseye (May 12, 2006)

Well..... I can personally vouch for overflows being safe.... I LOVE them... I use one on my 20Gal and 30Gal plant tanks (both glass).... The acrylic doesn't weight that much and there is probably only 1/2gal of water or less held in the overflow its self. Nothing to worry about there.... the full overflow weights far less the the custom wood canopy's you see on peoples tanks.

Best of all..... Allows me to keep all equipment out of the tank..... 

Using thin glass between compartments I think COULD lower the overall water temp a few degrees ... but you are correct, the heat exchange would be vary inefficient... probably if nothing else making it nessesary to run your chiller at a much lower temp...

Something else that just occurred to me: Why not split the intake and output of the chiller? a "Y" on the intake side with a line going to each tank and a "Y" on the output side going to each tank. Could be balanced with simple valves on each end of the Y's... but again this means mixing water systems...

You know... I thought about you while doing maintenace on my tanks today.. I keep several native tanks containing Native fish and plants ..... These tanks are maintained without ANY regard to temp - because all life in these tanks are simply accustom to the climate here in Louisiana (USA)...... The same should be true for you concerning pretty much any tropical fish or plant - a large number of them are native to your country or another with a very similar climate *shrug* . I'm saying this ofcoarse without knowing what kind species you are trying to keep.

I also once had a talk with a gentleman in Iraq I believe it was..... where temps are VERY high and aircondition was scarce and he had almost no problems concerning temp..... because most any plants and fish simply adapted (and very quickly) to his climate.....

All that being said - I really question the need for a chiller in your case unless you are keeping saltwater (which even then a fan in the canopy would probably do) or coldwater species...... I see from your profile that you have a good bit of light over your tank so if your lights are heating your water too much it may be easiest/most practical to vent your hood and/or install a small fan (to the cost of about 10$)....

...Perhaps you need the chiller because you simply want it.... and thats OK too 

".....back to tank A is still contaminated ...."
LOL.... you care correct, never crossed my mind 

http://en.wikipedia.org/wiki/Thermal_conductivity

back to the original idea -- Shown in the link above is a chart displying thermal conductive properties of a range of materials...... while copper's conductivity is much higher than glass I think that its worth noting that Glass is slightly more conductive than water its self..... I would think that to mean that the water in the two end compartments would reach the same temp as the water in the chiller compartment....

In yet other words - The maximum thermal conductivity that you will be able to reach in any case ..... is that of water itself..

Take care,
-Justin
One Mynds Eye


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## yxberia (Apr 19, 2005)

Wow, that's very thoughtful. 

Nope, we seldom keep native species. They are hard to get in LFS these days unless you live in outskirt area. The reason for chiller is because the room temperature here can go as high as 31 C at night. The 2.5 feet, also in the same room, which is now cooled by 2 x 12V PC fans can go only as low as 30.1 C. With 2 x 150 watt MH over the 4 feet, algae could quickly take over the whole tank. 

Ok, back to the 1-Chiller-Many-Tanks idea:
I have another crazy idea. 
1. Tank A, B, C(reservoir).
2. Install Y splitter on the chiller outlet. Flow is splitted towards A and B tank.
3. Install aluminium coil on each A and B. Water runs thru the coil, heat exchanged.
4. Now, the water after flowing thru both coils will NOT go into A nor B. It goes into reservoir C. There, the water will be circulated back to the chiller by a cannister filter. This reservoir can be a thick plastic/polyfoam box to keep heat from getting into the system.

Now you have an "extensible cooling device". Just keep adding Y join for additional tanks. And you should use coolant for the extreme edition. 

The only problem is, still: THE COIL. 
I know we can twist and turn any small metal tube into a coil easily.
But, does aluminium affect lifeform under acidic medium (CO2) is still questionable.


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## onemyndseye (May 12, 2006)

sounds like it could work  .... Brass may be a better choice


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## yxberia (Apr 19, 2005)

Brass....where can I find it ? Is it the same as copper fitting for air-conditioner ?


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## slickwillislim (Oct 11, 2005)

Isn’t brass just copper and zinc? Wouldn't it still be too toxic? I am curious what aquarium chillers use. Titanium, aluminium?


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## yxberia (Apr 19, 2005)

Most chiller use Titanium, that's why they are expensive.


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## onemyndseye (May 12, 2006)

Um.... yeah actually your right - I should have thought of that 

The Heat exchanger in most chillers are titanium or stainless steel as far as I know (or can find with a brief search on google.com)

It seems that I've read somewhere that Aluminum is not aquarium safe... Especially at lower PH's where it can cause metal toxicity... But now I can seem to find the article... On the other hand - Softdrink cans come to mind and Coke for instances is quite acidic so I dunno.

Also, a problem with splitting the chiller many times.... pretty soon you will be beyond the chillers cooling and pumping capacity 

Take Care,
-Justin
One Mynds Eye


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## titan97 (Feb 14, 2005)

As a metal finishing chemist, I feel that this question is right up my alley. 

1) You last idea is the best. Using heat exchangers (aka coils) will allow you to chill both tanks without cross-contaminating the tanks. We do this all the time on anodizing and plating lines.
2) Aluminum is a bad idea. In an acidic environment, it will eventually dissolve and contaminate the bath. Too much Al and you will kill off the bacteria and eventually the other life forms.
3) Brass is just copper and zinc. Don't use this either.
4) Titanium is the best for acidic fluids. It becomes passive and will not dissolve. Stainless steel can also work, but it will (very very slowly) dissolve. If you do go with stainless steel, get the highest chrome content possible, like 316. The 303/304 stainless is cheaper and softer, but it will breakdown faster.
5) We also use plastic tubing for our heating/chilling coils in this industry. Chrome baths love to chew up every type of metal. A Ti coil only last 2-4 weeks on average. Forget about stainless steel or any other material. For chrome we use Teflon tubing. Now, it won't conduct heat as well as the metals will, so we have to use more tubing, generally 4x the surface area of the metal coil. You should be able to find some tubing to work for you. A thin wall tube is better, but will tend to kink easier. 1/4" tubing should be about right for an aquarium. The number of coils or the total tubing length will require some experimentation.

Regarding soft drink cans, they are coated to prevent attack on the Al. They use a phosphate or zincate type conversion coating to protect the can. If you look inside of a can, or open one up, you will see that the can does not look like normal Al. Instead, it should be opaque or matte.

And I also agree that you may be beyond the chilling capacity of the chiller with more than 1 or 2 tanks. 

I would also recommend that you direct a strong flow from your filter output or a powerhead onto the coil. This will help maximize your thermal exchange efficiency.

Normally, we can buy a Ti coil for about $200-$300 which weighs about 10 pounds (5 kilos). You may be able to find a much smaller coil (2lb or 1 kilo) for about $20-$50. 

-Dustin

I would also install a valve for each tank. This will allow you to customize the required temperature of each tank independently.


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## yxberia (Apr 19, 2005)

Dustin, great post! You're the man! :hail:
That's a lot of useful info for us to digest! :hungry:

The chiller is designed to handle 6 feet tank. Since planted tank does not require temperature that is too low, I think it can still handle 4 + 2.5 feet.

Titanium - cost is out of reach. With that price, I can get another moderate quality China chiller.  

Stainless steel - I have done some survey. The SS tube I can get here are mostly coated on the outside. Inside is bare, I can see beige color on the inside tube. Why is that ? This 1/2" tube is used for bathroom fitting - curtain rail.

Once again, thanks for sharing.


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## titan97 (Feb 14, 2005)

If it is coated, then it is usually not true SS. A lot of bathroom fixture companies (which are my biggest customers) actually plate nickel over the base metal and clear coat it. They sell this as a stainless steel imitation. 
Is the beige color paint, or is it the color of the metal. If it is the metal, then this might be either nickel or brass. Brass is (usually) very yellow. Nickel looks much closer to chrome or steel, but with a slight yellow tint.
Using this tubing may be an issue. If you try to bend it, the coating may crack, exposing the aquarium to nickel. While it won't cause problems immediately, it will eventually dissolve like aluminum.
I still think that your best bet is plastic tubing. Nylon or Tygon tubing would be ideal. You should be able to find plenty of this at a hardware store. Just try to find the one that will not kink when you bend it.

-Dustin


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## yxberia (Apr 19, 2005)

It is the metal itself. Looks like plastic and not shining at all.

I was thinking of using pipe water brass fixture. I know there could be possibility of metal poisoning, but analyze this:

1. If brass fitting for household water system causes poisoning, human would have suffered long ago and we would have stop using it ? Even aquarium water that sourced from the same fitting will suffered from copper toxication? 

2. We could argue that since water keep flowing thru the brass, so the toxic won't build up even for a very long time. If this is the case, we could do away with simple water change every week as usual ? Then we won't have toxic build up problem ?


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## onemyndseye (May 12, 2006)

I think I can answer this one 

At PH's above 7 there isnt much of an issue with brass.... thats why most tapwater had a PH of 7+ ...

In a CO2 fed tank the PH usually falls under 7 and you start having the issue with metal toxicity. Even without the PH falling under 7... with pure CO2 dissolved in the water I would be afraid of the effect the gas would have on the brass.

-Justin
One Mynds Eye


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## titan97 (Feb 14, 2005)

Justin is right. One more thing to consider is that SOME Cu and Zn are needed for normal cellular life activities. Just like almost every other metal or element. Just look at how Seachem's Florish Trace is packed full of different elements. The problem is that at a certain point, Cu becomes problematic for the microbiotic life. The bacteria of the tank can be killed off by this. Increase the concetration a little more and your start affecting higher life forms (mosses, plants, etc). Granted, you may never see this with a weekly water change. However, I've seen my snails and shrimp die within a few days of introducing copper to the tank. My kids love to throw money into the fish tanks.
CO2 gas should not have much of an effect on the brass, or any metal really. 
Regarding copper piping in homes: Generally, the water doesn't dwell long enough for it to pick up much copper. We're talking on the order of 0.01ppm or so on average. Many brass fixtures also incorporate lead into them as well for ease of machining, and this can get into your drinking water, too. This is why in the US any internal parts of a brass fixture need to be low lead (or lead free) or have some sort of tubing. 
In an aquarium, we have the two-part problem of low pH (typically) and constant exposure to the water. You may be able to use this material, but I wouldn't want to risk it. Like I said before, I'd rather use plastic tubing.

-Dustin


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## yxberia (Apr 19, 2005)

Got it, thanks.


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