HCA: Hermit Crab Association

Kudos to you for wiring it yourself. :) I don't have a flexwatt, but the one thing to look out for when heater any aquarium with a mat of any sort, is cracking; I've yet to see a heat mat designed for aquariums. The temperature differential between the water and the heater can crack the glass. But f...

I don't have one myself but here's a link to some reviews: http://petcareguru.net/zoo-med-hygrotherm/ From what I've read, the hygrotherm isn't bad, but you still get what you pay for. I doubt the accuracy and quality of the sensors matches that of the spyder robotics units. There's only so much 70$...

^Actually they have a humidity one: http://spyderrobotics.com/products/herpstathumidity.html Though... at $189US it it most definitely isn't cheap. A combined temp/humidity one would be nice and possible cheaper, as having a humidity unit plus the thermo unit would run you up to 300$ for the cheapes...

That looks like a very impressive device (hmmm... perhaps a reverse-engineering project could be in order :P ). Did you add a second thermostat inline with first? The manual recommends a second one if, for any reason, you blow the electronic switch (TRIAC) that varies the power output to your heater...

I'm guessing you mean these ones . I have those, too (except the water lettuce). They look great floating above the water. Except if you leave them alone for a while, they tend to clump and get stuck in the sand. :roll: But they're good for making sure smaller hermits can make it out of your water d...

Don't listen to your mom's bf, 3 inches is fine :roll: My male fiddler lived for over 3 years (full lifespan of a fiddler) in that water level... no problem. They're shoreline brackish crabs. I've even had the opportunity to see one fiddler species in the wild (Uca Pugilator), and they come out at l...

Alice (I like that name :) ) most definitely has eggs. I responded to your PM, so you'll find my full response there. Don't worry about your pics, the first is excellent quality, just the last is a little bit out of focus. Congrats on your fiddlers mating! And I would love to see a full picture of y...

Usually people just buy plastic plants and vines, going for the "natural" look... creating clay figurines isn't usually done, so aside from Fimo or Sculpey, I don't know of anything else you could use. When fired, though, I would think most pottery (both clay and ceramic) would be fine. The glaze th...

I kind of performed some surgery on my circuit the other day, so setting the thermostat is more user friendly now (and uses less buttons). :) I've used a bi-colour LED (a red and a green LED both encased in a single package) for power; it lights up green when the controller is running normally, red ...

Fimo clay is based on PVC (polyvinyl chloride), which by itself is a common plastic. From wikipedia, it appears the company used to add phthalates (which can be somewhat toxic) to soften the clay until 2006. So if your Fimo was made after 2006... then it might be okay. Apparently it's "non-toxic", b...

This sounds like a pools project... :wink: I like the Dive clean mini/micro for pools, as it's very small yet very powerful for its size. Kili mentioned the Hagen Elite Mini for your other question before, and I have one for my green crab. It's larger, the same price, and around the same output pres...

Sorry I haven't been here for the last couple days... I went to a friend's cottage last night. :) A scaled-down version with a few temperature and humidity probes would be 100-200$, whereas the full unit I've been building has 8 sensor inputs (including one for pH) and 3 thermostats/humidistats, and...

Thanks :oops: If you could get something to test water, and sand temps that would be REALLY cool too. It can test water pH, and the temperature probes will be molded likely either in silicone or epoxy, and possibly within a nickel tube (it won't rust or corrode so is not dangerous to any form of wil...

I got the humidity sensor measurement working today!! It's accurate to about 3%, and incredibly stable. Now all I have to do is add it to the rest of the circuit, then construction begins!!

~Ryan

I made some progress with the humidity sensor circuitry today (to the the tune of a page of math and formulas to design it )... It gives a reading proportional to humidity, but the scale is way off. At 70% RH, it reads below 50%. But oh well. There's always tomorrow.