Designing a DIY RDWC with Built-in Chiller

Thinking ahead for my jump into hydro… I will most likely need a chiller. I have an old one left over from my reef tank days, but that’s been a 10-15 yrs at least. It probably won’t work anymore, cause that’s just my luck.

I think I found a solution that is feasible to incorporate into a DIY RDWC 10 gal tote build. I will be adding a $12 part to the controll reservoir.

It is temperature controlled and claims a 10F pull down. I think it could be a solution for my thrifty needs. Plus I have an old computer power supply that I could tap into the 12v line, further reducing build costs.

The plan is to use an small trash can with a flip up lid as the Control Rez and incorporate this into it. This is an evolving idea. I’m working the design aspects of my build, and I could use some input.

Let’s discuss the pros and cons here, folks.


@TDubWilly @BIGE @dbrn32 @DoobieNoobie


I like the idea of the thermoelectric cooler. It would work good in a small system but you have to understand best case on those is 10 degrees below ambient temp. Ah I just seen you know that lol. Well I can confirm those will pull down by ten degrees. But they work far better in a cooler atmosphere. And their prone to freezing up on the fins due to condensation. Once they get enough ice on those fins it stops working until you shut it off and let it thaw.


I wonder how many of those you could run on one power supply using one from a PC? I think you could use a small pump and a little bit of plumbing engineering to run 3 or 4 of those to get much better results.

The controll reservoir and return pump will be outside the tent. The ambient room temp plus the thermoelectric cooler, should keep the temps in line, right?

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The power supply is just for powering the cooler. The rest will be plumbed and will have air pumps.

My favorite vid so far. This won’t be the actual design, but lots of good idea came from it.

Yeah that’ll help a lot. Plus it’ll be less humid outside the tent. That’s really how they work best by being in a stable environment. With that much water I’d run the cooler full time and it should be a noticeable difference.

I watched all his videos. He’s super long winded but he’s done some solid work and he can definitely grow.

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I’m holding a solid 10 degrees below room temp just by keeping the light from hitting my reservoir or totes. That plus a small amount of cooling would likely get to the right temp range.

I’ll be adding a ac unit as well soon. I plan to run half the vents into a hose that blows into the area around my reservoir. I’m hoping that’ll be enough to get my temps where I want them.

That’s what I’m hoping also

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I couldn’t even dream of doing this before building my light. I was running 2 blurple in veg and 4 in flowering. I had to pipe the ac into the tent. Now the tent runs 1° over ambient room temperature.

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I have the stuff to build one, just haven’t gotten around to it. 10f seems like a lot for something that size of res. But I can’t say it will or won’t work.

I used to have a reef tank too. What a money pit! Have you seen the diy chiller builds using a mini fridge?

Yes, but that would just be adding more heat into the room.

My room is in a insulated garage. So although it’s much cooler than outside in summer and warmer in winter it needs something to get it stable. So far the lights are more than enough to keep warmth. And my water temps will get cooler as winter comes on. But summer time I’ll need a little help to get the heat down.

I have most of the parts minus the plumbing already. I don’t see this happening any time soon, as money is always tight. Ima planner! I like to cover all bases before hand, and drive my brain crazier over time, before coming to the final design.

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Don’t buy that chiller then. When I get around to building this one, I won’t have a use for it. I’ll send it to Rick or something.

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It’s using something like a 50 or 60 watt peltier?

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