Right, so if you're reading this it's probably because I directed you here because you're interested in buying a Poison Dart Frog (PDF) from me and had some questions. Hopefully this post will answer them! If I didn't refer you and you just happened to find this page, well, still. Hopefully it'll answer your questions!
Intro
First, a bit about me. Namely, why you should trust me. I have owned PDF's for roughly 20 years (with a 6 year gap when my husband was stationed in Hawaii and I had to sell my collection). I've also owned and bred mantella frogs, bearded dragons, and viper geckos, and owned snakes, and terrapins, including a 25 year old pong turtle who is as ornery as ever. I'm far from an expert, but I'm not a novice. I know what works, and what doesnt.
About the tanks
First of all, like most veteran PDF owners, I LOATHE the term 'bioactive' because it's redundant. Any halfway decent PDF tank IS bioactive; it's something we've always done in the hobby because it's what works. So yes, technically these tanks are bioactive, but I'm not going to use that word further. It's buzz word, jargony, marketing. Blech.
Building a tank
Size
First of all, I'm cheap. You can definitely buy a nice front opening exo terra, but those are more expensive. They work really, really well. But I usually go for a standard tank. You can get them either during Petco's $1/gallon sale or on craigslist. Cheap! I never use less than a 20 gallon, and I prefer either a 20 tall or (even better) a 30 gallon. You'll have a few options for lids. You can use a cheap screen lid, but if you go that route, make sure to fully cover it in plastic wrap. It wont look as nice, and fruit flies can easily escape but it'll do the trick in keeping humidity up. You can also buy a premade glass top. These usually hinge in the middle and are much easier. They're more expensive. Your cheapest option will be to go to a home improvement store with your measurements, buy two panes of glass, and silicon them together. There's tons of youtube videos on how to do this. It'll work just as well as the premade kind, but at a fraction of the cost.
Background
You can go all fancy with foam and all that, but I don't have the patience for that, and like I said, this is for a basic tank. I use coco fiber mats. They're easy to install (just silicon in place- use 100% pure silicon, with no mold inhibitors), plants love them, and I think they look good. Have them start all the way at the top, and go down to within 3 or 4 inches of the bottom, you'll cover up the bottom with substrate, but you don't want too much of it in the drainage layer as it'll wick water up and cause mold issues.
Substrate
Your substrate will have a few layers.
First your drainage layer. You've got a couple options here. LECA (or hydroton) is light weight, easy to find, and inexpensive (just rinse off the dust before using). You can also use any kind of clay aquarium filter media, although it'll likely be more pricey, so I would only do that if you have some lying around. A newer option is matala mats. I hear great things about it, but I haven't used it myself, so if you want to do that, you'll have to find a different guide. You'll want at least 1.5-2 inches of drainage.
Next you'll need a barrier. That's easy. Plastic screen from your local home depot will work well. Cut it so it'll be about an inch over around all sides and set it on top of the drainage layer. Some soil will get through, but as long as most of it stays out, you're fine.
Next soil! ABG is the standard. It's a mix of coco, sphagnum, and charcoal. It holds moisture well without being soggy, plants love it, insects love it, it's good stuff. Buy at least enough for a min of 2-3 inches, plus more to build hills and such.
Lastly- leaf litter. This is super important. Oak and magnolia are good choices. If you have a spot that you KNOW is pesticide and insecticide free, go ahead and grab several handfuls. You'll want all dirt covered. The reasons for this are threefold- 1. It helps keep moisture stable in the substrate. 2. It gives insects places to hide and breed. 3. It gives your frogs places to hide. Frogs that feel like they can hide easily are bolder, and you'll see them more than stressed out frogs in bare tanks.
Plants
There's a ton of great sites that sell really cool plants. I get most of mine from Josh's Frogs and Glassbox Tropicals (actually, I get most of all my supplies from them, along with Houston Frogs and NEHERP). You'll see really cool, expensive ones and may be tempted. Don't be. They're usually more expensive because they're harder to keep alive, and if you're reading this, you're new to the hobby. I suggest buying the kits that have several different things in them.
You'll want some moss (just because it's pretty, the frogs don't really like the moss much, and insects definitely don't like it as much as leaf litter, so you don't want it covering the entire bottom of the tank.
Bromiliads are great because they're often where PDFs naturally breed, plus they'll be attached using plant wire (or toothpicks, or bent paper clips, basically whatever you have on hand) to the back, giving the frogs stuff to climb on and making your tank more aesthetically interesting, not to mention they come in just about all the colors.
Ferns grow really, really well in our tanks, and are usually dirt cheap. The risk here is that several of them will outgrow the tank really quickly, so they're good to put in right away, but understand you may have to rip them out as they get bigger and start to block light and choke out the other plants.
Orchids are awesome! But they're a bit harder to keep, so I'd stay away from them for now.
There's a ton of other plants that do well too, but if you stick to the kits, you'll get plants raised in frog safe environments (no poisons), that are easy to care for, and are relatively inexpensive.
Other decor
Right, you've got dirt, you've got plants, you've got a background, but you're not quite there. Most frogs like having a cocohut to breed/hide in. They're cheap, they blend in, no worries there. If you want to breed your frogs, put a well washed pringles lid under it. They're the right size and easier than trying to order a single petri dish. You'll also probably want some wood. Grape vine looks cool, but molds and decomposes really quickly, stay away from it unless you want to rebuild your tank in a year. I like cypress and manzanita. Both hold up well in humid conditions and usually look interesting. You can also attach your epiphytes (plants that grow in the air- bromiliads, orchids, some ferns, mosses, etc) to them, and the frogs will love climbing on them. You can always add rocks too, but remember that rocks wont help support insect life, and are heavy, so use minimally.
Lighting
I'm not going to lie, this is where it gets complicated/expensive. Seriously, the light will probably be the single most expensive thing you purchase. You'll want LED wand lights. They give off the right spectrum for plant growth without giving out heat. I'll check which kind I have later, but in the meantime, just look for LED grow lights.
Microfauna
Ok, so you know how I keep mentioning insects? That wasn't quite accurate. You'll want lots of bugs in your tank, but they wont all be insects. Mostly you'll need two species to start with- tropical springtails and isopods (which aren't technically insects). The springtails eat mold, the isopods eat decaying plant matter. Both make tasty snacks for your frogs. They'll keep your tank looking clean and neat, keep your soil healthy, prevent build ups of frog poop or mold or dead plants, or whatever. Just make sure to get the tropical kinds. Your isopods you get in your garden (otherwise known as rolly polly's) get too big for your frogs to eat, and don't like how warm it is in there.
Water
"Wait!" you say, "what about water? Don't frogs NEED water?" Yes and no! You don't need a pond of any sort, in fact, as PDFs are not great at swimming, it's advised that beginners avoid them (they're also much more complicated to set up properly with sloped edges, filtration, all that). But they obviously are amphibians, so you will need to keep them damp. You'll do this by misting a few times a day. You can buy a misting system (mistking is the industry standard) or mist by hand with a spray bottle. I'm cheap and my tanks are all over the place, so I just mist by hand. Use filtered water without a ton of chemicals in it (you don't want mineral deposits on your glass, and depending on your tap water, it may be high in chlorine and all that junk, you can take it to your local fish store to check). I like misting by hand because it gives me an excuse to look at them, but the misting systems definitely are more convenient, especially for when you go out of town or just get really busy with life.
PDF Care
Ok, so you're got your tank up and running, you're ready for frogs, right? Woo! That was the hard part! The only thing left now is how to feed them. PDF's eat fruit flies almost exclusively (the exceptions being your springtails and isopods). There's two kinds (both flightless, btw)- melanogaster and hydei. Melanogasters are smaller, but breed quicker and in greater number, hydei are larger, but take long from setting up the culture to being able to feed out of it. I HIGHLY recommend making the cultures yourself. I use any media from the previously mentioned sites, they're all good, I just get what's on sale. You'll use plastic cups from those sites (or you can shop around restaurant supply companies, it'll be cheaper that way, but more of a hassle). You'll want the lids with the holes punched out and a piece of cloth covering them- the kind with smaller holes pricked in them don't work as well. Make the media according to the directions. You can start feeding out of them once you get a bloom (when suddenly you have a bunch of flies), but don't use those flies to start new cultures until a few days after as males tend to hatch first, and you'll want a good mix of male and female flies for your new culture. Even if it seems like too much, make at least 1 or 2 a week, that way if a culture dies, you wont be scrambling to find food. Young frogs will need to eat every day, adults only every other day. You'll want to dust with vitamins and minerals every single feeding. Use 2 kinds- the main one will be a multi vitamin with calcium and vitamin D. You'll also need a separate Vit A supplement that you'll use once every other week, or up to every few days IF your frogs are actively breeding a lot. If they're not, every other week is fine. Vit A is necessary for health, but is easy to OD on, so don't give it every time.
FAQ
How do I check temp and humidity?
You'll want to keep the temp preferably below 82, but DEFINITELY below 85. Basically, if the room feels comfortable but a bit warm for you, it's good for them. You can buy thermometers from any pet supply store. I suggest ones that record highs and lows. Use that for a few days (and nights) to make sure it stays good. Occasionally in the lower 60s in fine, but you'll generally want the lows to be high 60s/low 70s, and the highs to be high 70s/ 80,81. There are gauges to check humidity but they all suck. As long as everything inside looks damp and there's some condensation on the glass, you're good. If you get frogs and they're hiding all the time, increase the humidity.
AACK!! What's up with all this white mold everywhere?
So, you've finally got your tank set up, and it all seemed good, until a few days go by and then suddenly everything is covered in white mold! Oh no! Naw, don't worry. That's completely normal, wont hurt anything, and your clean up crew (the springtails mostly) will make short work of it. Seriously, it's totally fine and completely expected. You might also get mushrooms or random mosses. Most of those are super fun little bonuses! The only ones I don't like are the big yellow mushrooms because they cover everything in yellow spores. It doesn't hurt anything, just looks ugly.
Right, I'm gonna go ahead and publish this even though it's not quite done. I'll add pictures and more info on lighting, but right now I've got to go pick up the kids and then go to work. :) Hope this helps!