DIY Chiller

[whuntley]

Copper can be very very bad.

Our Environmental Protection Agency has started mandating the addition of strong caustics (usually sodium hydroxide or lime) to domestic water to hold the pH above 7.5 or 8. That retards the copper etching and (particularly) the leeching of lead from the solder joints.

Copper and lead are heavy-metal toxins, and they are not reactive enough to form the solid (sapphire) coating that forms on aluminum as soon as it is exposed to air. The patina (green coating) on copper and the whitish lead oxide film are just not solid enough to be really protective if the pH of the water falls below 7. [I have killed whole tanks of fish before I learned that.]

Of course the EPA mandate does a number on our fish if we let ammonium get much above zero (as in shipping). I add about a double or triple dose of "Amquel" to all shipping water in an attempt to avoid sudden deaths at the other end. YMMV.

Wright

[TyroneGenade]

the water in the tank exhibited a slight tinge of brown when I came home from work this afternoon

This is probably copper sulfide. Copper will precipitate with sulfides (remember hydrogen sulfide gas produced in anaerobic substrates) an din effect be neutralized. The odds are the water pumped through the copper piping has peformed a similar trick and the pipe is now lined with an insoluable copper sulfide coating.

Copper Sulfide will only dissolve at a rediculously low pH (so low I think the calculation I just did has to be wrong, I invite people more mathematically sure of themselves to look here:http://www.chem.ubc.ca/courseware/pH...8/content.html).

For now you are safe... but keep checking that Copper reading and doing water changes just to be sure.

tt4n

[scstormwolf]

how do you drill the hole on top of the fridge?

This unit is certainly very interesting. What about using those mini portable fridge which are quite popular now in the market?

[whuntley]

Those use Peltier cooling, which is more efficient if applied directly to the back glass of the tank, I suspect. Unfortunately, they are too weak for most tanks.

Basically, they contain a thin plate that is like a whole bank of thermocouples. When heated a thermocouple produces a current when there is a difference in temperature between the "cold junction" and the "hot" junction. When *driven* by a current, a temperature difference develops across the thickness of the plate.

If the cold side is bonded to the aquarium glass, and some finned aluminum heat sink material is on the hot side (slots vertical to encourage convection?), you can create a cold spot in the tank wall. Use some silicone to bond another set of fins inside the glass to improve efficiency at the cost of good looks.

Unfortunately, you may need a half-dozen of them to make a significant difference in a larger tank. Insulate the tank ends, bottom, and back, too.

They make gadgets to cool the CPU in your computer that work on exactly the same principle. Both portable picnic coolers and CPU coolers usually also incorporate a small fan to cool the hot-side fins.

The same unit can be chiller or heater by simply reversing the current direction. My guess is that a 200L tank would need something like 300W of well-designed Peltier cooling/heating. Most picnic coolers are probably about 50W or less -- hence my guess of about 6.

Wright

[scstormwolf]

anyone thought of making this unit and selling it?

If so, i am interested.

Maybe I provide you with the necessary equpiments and you fix for me or you get all the stuff and you fix it.

So anyone??? Price must be reasonable of course.

[RonWill]

anyone thought of making this unit and selling it?
If so, i am interested.

Dear What's your name "scstormwolf",
I, too, am interested in rigging up petier-cooling for smaller species tank and it would be nice to know who I'm sharing the project with.

You may have noticed that over here, we address each other in our real names. None of us here really bite, except Budak (I think :wink: ), so do let us know who and where you're coming from. Much appreciated.

[scstormwolf]

Alright, my name is Sam. Singapore.

[RonWill]

Sam,
Thanks and welcome to the forum. Our purpose for petier cooling may be different; perhaps planted tank for you but personally, it's a goal to be able to maintain cool water killies like Diapteron. [real pretty fishes. Look here]

Although electronically-challenged, I can still help with drilling holes, some soldering and other odd end stuffs. When we're able to get all the parts together, I can pull in a friend to rig it up.

[stormhawk]

Ron, its Peltier, not petier. I've seen an article regarding this method on a Japanese killie hobbyist's site. You need an online translator to roughly understand what's on the site. Very simple idea like what Wright has mentioned earlier. The cooling effect, according to the article only takes effect in smaller tanks, perhaps 1ft tanks would be a good size to test. I can't recall where I came across this article but if I do I'll email you the link. Very simple idea using the Peltier element, a heatsink, a normal PC fan and a short length of tubing.

[scstormwolf]

i am using it for marine tank. but i believe it will do just fine. Anyway, I am looking to fix up a DIY chiller. Looking out for a barfridge right now. Still wondering if a mini fridge will work for my 3ft tank. But I doubt so.

[timebomb]

Hi, fellas,

The copper tubing didn't work well. With it, the temperature of my tank hovered around 23 to 24 C most of the time but the fish and plants were not taking it well. The other Notho rachovii died 2 days ago although I changed half the water in the tank everyday. Here's a pic of the poor bugger before he died:



Almost all the other fish didn't show any signs of ill-health except for a Croaking gourami that developed some fungus on its back. As for the plants, a Tonina-like plant I had started to melt and some of my mosses began to turn brown. My Willow Moss, in particular, seemed to suffer more than others. It was looking great before I changed the hose into a copper tubing. Here are before and after pictures of 2 of my mosses, the Willow and a species of Fissidens Moss.

Willow Moss - Before the copper tubing:


Willow Moss - 3 days after the copper tubing


Fissidens Moss - Before the copper tubing


Fissidens Moss - 3 days after the copper tubing


So I decided to take out the copper tubing and replaced it with something else. Gan C W was with me and we went shopping for a better hose. We went back to the same shop where I first bought the so-called PVC 50 metre hose and they insisted that the hose I bought earlier was really PVC. They said there are 2 types of PVC, one hard and the other soft. The hard ones are what we used for piping around the house and the soft ones are used to make hoses.

Anyway, the previous hose I was using is too soft and it kinks easily. So I decided to buy something thicker. The shop owner recommended this - a braided hose.



It's 50 metres long and is thicker than the previous hose I was using. It definitely won't kink but the conductivity will probably be poorer. The owner said it's PVC too and the cost for a whole reel is $58. Ouch. I decided to give it a try.




The temperature in my tank yesterday was about 24 to 25 C. The temperature in the freezer was about 20 to 21 C. Seems like the gap has widened because of the poorer conductivity of the hose.

It seems like I won't get to see 22 C in my tank after all. Then again, maybe I will in December when the monsoon season comes around.

Loh K L

[zmzfam]

KL,

I noticed from the last picture that you are still tightly binding the coil. Why don't you loosen up the coil a bit.

As for the copper tubing, perhaps you can ask around if anybody can cure the inside of the copper tubing. I'm sure your house is using copper pipings (as do mine) and topping up direct from the tap does no harm as (has been mentioned previously) the inside of the copper will form an inert coating.

That said, however, the water coming from the water-tanks is slightly neutral to alkaline whereas the water in your tank is slightly neutral to acidic, and it is always in contact with the copper.

Did you test for copper again? I'm sure the test kit can picked up some readings if your plants are in that state.

[TyroneGenade]

Cap one side of the copper tubing, fill with water and leave in the sun. Change and test the water every now and then. When the copper pipe water tests 0 for copper try it in the tank.

tt4n

[whuntley]

Do as Tyrone suggests with one small addition.

Add enough vinegar or pool acid to the water to overcome any buffering and make it definitely acidic, say a pH of 5.5 to 6. If the water is above 7 it will not show much when you test for copper.

Do the pH test before and after the sun soak, to be sure the pH hasn't "bounced back." [Harder water may resist staying acid and more vinegar will be needed until all the buffers are used up.]

Wright

[Kenji80]

What is the glue that you use to join the inlet and outlet to the freezer?

Can I know the brand and where to get it?

Thanks.

[Kenji80]

Can someone help on this?

What do you all use to join the inlet and outlet to the freezer?

Thanks

[stormhawk]

Kenji80 (what's your name?),

I don't think there was any glue involved. Silicone sealant (aquarium-grade) would do just fine in securing in the inlet and outlet points and preventing any leaks. Read through the entire thread for a better understanding of how to construct the chiller and the necessary items for making one.

[Kenji80]

Hi timebomb,

Can I check with you where did you buy the braided hose?

What is the size of the hose?

Thanks.

Regards,

Yongda.

[Kenji80]

Anyone can help?

Thanks.
Regards,
Yongda

[timebomb]

Here's the address of the shop:

Chuan Hup Huat
Block 809 French Road
#01-184
Kitchener Complex
Singapore 200809

The size of the hose is exactly the same as the one from Eheim.

Loh K L