Thermostat(s) for 8-10 high rack

I've been meaning to build a legit rack for my BPs, but the thermostats cost more than some of my snakes; not to discount their inherit life value of course.

I am looking to build an 8-10 high rack from PVC board and would like to use either flex-watt or seedling germination pads as UTH often get too hot for plastics and even glass in some instances (I use rheostats currently). I also worry about off-gassing from the PVC once heated.

Herpstat 1, 2, 4, etc... all seem to indicate the number of probes they support. I've seen some BHB videos and he seems to use a Herpstat 1 on a whole rack. How is he doing this? Is he/people assuming since they are all the same output wattage that they should all have equal temps? What about rising heat (thermodynamics from other sources + hot air rises) from the lower racks? Wouldn't that ultimately mean the top rack is the hottest? I'd like to build a rack 8-10 high, but want to spend as little as possible (generally a bad idea) on thermostats as they can be $200-400 a piece for multi-input. I haven't seen at 8 input but I bet it's like a $1000.

Basically, for a rack this size ... how many inputs do I really need and the appropriate spacing between racks with probes and those without? Did I miss a sticky or something somewhere too?

TIA!

You really only need 1 thermostat per rack. Place the probe about midway and the temps will be fine. You'll experience a degree or two fluctuation from top to bottom normally, however.

Most of my racks have either a single heat source (in the form of a single piece of heat tape, or a single heat cable wound throughout the rack) or several identical heat pads all wired together. No matter the setup, all of my racks have only one plug, so they only need one probe/input. I've seen some people wire all the levels separately, but it's not a setup I'd prefer.

Usually there are a few degrees of temperature variation, but not enough to cause husbandry issues. In most of my racks I put the probe somewhere near the middle and try to shoot for 90F. The tubs on the top and bottom may get a few degrees higher and lower, respectively.

There are some exceptions. I have one rack that has perfect temps in the first four tubs, but I can't seem to get the bottom tub over 85F. So I keep my kingsnake in there. It was a homemade rack I bought off another breeder, so I'm not sure why it does that. Then there's the rack with identical heat pads, (another homemade rack I bought off a diffferent breeder) which was setup ins such a way that the tubs completely cover the pads everywhere but the top, so I had no choice but to put the probe there. I set the thermostat a bit higher and it regulates temps just fine.

There are also a lot of variables that come into play. A closed rack will hold heat better than an open one, and the room's ambient temperatures will influence the ambient temps in the rack to some degree. I generally prefer closed racks, since I keep my room around 75F.

So in short, you will need a probe for every power plug. You could wire each level separately and probe all of them if you're super anal about temps, but it seems like a lot of unecessary work to me when you can use a single heat source on a single probe for the whole rack.

I have an 18 tub 9 shelf rack hooked up to a VE‑200 T-stat. I used an adapter (converts one plug into two) I picked up at Walmart as well as two 6 plug surge protectors. I placed the probe mid on the mid level shelf. The VE-200 handles up to 700 watts. So since each three foot section of 4" flexwatt is about 18 watts I was well under the limit. No issues with higher shelves being hot compared to the lower shelves except maybe by a degree or two.

Quote:

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Originally Posted by PghBall

I have an 18 tub 9 shelf rack hooked up to a VE‑200 T-stat. I used an adapter (converts one plug into two) I picked up at Walmart as well as two 6 plug surge protectors. I placed the probe mid on the mid level shelf. The VE-200 handles up to 700 watts. So since each three foot section of 4" flexwatt is about 18 watts I was well under the limit. No issues with higher shelves being hot compared to the lower shelves except maybe by a degree or two.

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Here's some pics. https://uploads.tapatalk-cdn.com/201...4450e9ae7c.jpghttps://uploads.tapatalk-cdn.com/201...7e4792993c.jpghttps://uploads.tapatalk-cdn.com/201...1da7b27c8a.jpg

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I am running a Vivarium Electronics VE-100 thermostat with a single probe on each of my 10 tub melamine racks (3 of them) and i've never had a problem. As others have already suggested, just tape the probe to the heat tape on the middle shelf and you'll be fine. You could actually use one thermostat/one probe for multiple 10 tub racks if you wanted to wire them all together just so you don't exceed the thermostats wattage rating. THG heat tape is heavier duty and much easier to work with than Flex-watt, by the way. But, that is a matter of personal preference...