Temperature Controller

[n8rad]

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[BigDave]

I did something pretty similar in my Arduino. Those relays are 5 Amp, so you can use a couple of heaters on the same relay.

I also used the second relay to turn a chiller on/off at a high point. The water from the return pump is always running through the chiller so I just have to turn it on when I need to cool the water.

I know that temp probe is stainless steel, but are you going to do anything to protect it any better? My plan is to dip mine in plasti-dip to protect it just a little more.

I also didn't bother with separate on/off temperatures. From the testing I've done, water is pretty slow to change temp on most aquariums. I'm not getting much cycling in my test environment at all. Actually, the opposite is happening in that the titanium heaters that I'm using are carrying extra heat into the bucket even after being turned off, which is raising my test water just a few more degrees after the heater is turned off.

[n8rad]

The stainless steel ones are crap. I wouldn't plasti-dip because you will not be accurate anymore.

Get this instead
https://www.sparkfun.com/products/11050

[BigDave]

Not to start an argument, but what do you think that sparkfun temp sensor is sealed with? It's just a plastic coated temp probe the same as me plasti-dipping the one I have. My understanding is that it would only cause the probe to respond to change a little slower.

I'll try plasti-dipping mine later this week and let ya'll know how it works. Right now I'm collecting data in a test environment, so I should have some data to compare it to.