DIY Chiller question

[cope413]

Alrighty, so I'm a big fan of making things for my tank. (I 3D printed my skimmer -been working great for about 2 months)

I've been looking around the interwebs for DIY chiller options. The only one I've found that looks promising is this one
DIY Aquarium Chiller

He is using it on a small shrimp tank.

I have a few peltiers laying around, as well as a very nice heat sink and PID controller. So I could put together something very similar for about $15-20.

The only thing I'd really have to source is the aluminum block.

So my question:

Is there any risk of using a small block of aluminum to cool the water? I know a lot of phosphate removal media has aluminum oxide in it, but I'm not sure what the form of aluminum would be from the block.

I would be using vinyl tubing in and out of the block, so we're talking about a 6-9sqin of aluminum (unsure of internal volume of the chamber). The temperature of the block would get down to about 8-9degrees F without water in it. I'm estimating it will be about 25-30 degrees with water running through it.

Depending on the flow, I should be able to pull up to 8 degrees off ambient at full power (somewhere between 250-300watts).

 

[Velodog2]

The aluminum will corrode quickly.

 

[cope413]

No, it won't. It's designed for water cooling and has been anodized so that it won't corrode, even with acidic solutions.

 

[Windy]

I spent 40 years in the aluminum industry. It will quickly corrode. The anodizing is only about 5 mills thick and any pinhole or scratch will start the corrosion. They use aluminum blocks on marine boats as anodes to control corrosion.

 

[cope413]

Hmm. Is it the salt? I've been running one on my PC for about 2 years with no sign of corrosion.

 

[Windy]

I understood you were putting the aluminum in the aquarium water. If you are putting it against the glass outside of the aquarium, it will corrode much more slowly.

 

[cope413]

It won't be inside the tank. It would have tank water running through it.

I'm looking for a high grade stainless or titanium option. Then I don't need to worry about it.