[Socratic Monologue]

If you search 'humidity', and order the results by date (thus reading the most recent hits first; this is a pretty good practice for most searches), you'll get a lot of good discussion about RH, ventilation, the use of digital RH meters, and "misting" (scare quotes because a better term is 'heavy rain' or similar). It'll be a fair amount of material to sort through, but reading the range of comments, and the range of ways to phrase similar recommendations, is quite valuable in such an easily misunderstood part of husbandry.

It might not be a bad idea to do the same sort of search on the plants you're considering; making sure you know what you're getting into especially with the Phal would be best (maybe you already have done this, I don't know of course). Posting a photo of the viv might get you some valuable feedback, too. I'm not sure I'd go heavy on ferns with leucs (ferns aren't too 'traversable'), but given the hardscape they might be fine. I don't see that you've mentioned hardscape at all, but since leucs are serious climbers it is a centrally important element.

 

[kismetwoof]

Thank you for the advice! I searched humidity but I didn't sort by date. I'll be sure to search again and read through as much as I can.
As to hardscaping, this would be the wood and rock I've included in the tank, right? I have wood (driftwood from amazon and one sycamore branch) and several rocks (mostly disinfected rocks from the river behind my house), and a store bought hideout that looks like stone). The "vines" are artificial.

Anything that is problematic can easily be removed/moved.

Here's the picture. I'm open to any constructive criticism so don't hesitate to let me know what needs to be changed.

Edit to add: I'm getting tincs

 

[Socratic Monologue]

The thing about tincs is that they're active climbers as well, but 'climbing' is kind of 'walking, but up high' for them; they're more so mountaineers than acrobats. Mine are up in the woodwork unless they're tending eggs or eating. So, a maximal amount of angled/horizontal branches that are thick enough for a ~2" frog (depending on morph/locale) to walk up are ideal.

Not that this is necessarily worth modeling a viv after (I'm more confident that I'm considering the right things than I am confident that I'm actually successful in a practical sense), but in my tinc build thread I try to talk about the reasoning behind what I'm doing. I continue to be quite happy with the hardscape in that linked viv (not sure how I feel about the plants, but I didn't give much thought to them and it shows).

Not sure who'll find this valuable, but: one thing that I've found makes hardscape design a bit easier is to buy wood (cork and ghostwood are my two woods of choice) in bulk in quantities much larger than I'll need for this one build, and sort through it to find pieces that work together. Small cork rounds from Pangea and ghostwood from Blooms and Branches are about as economical as this gets, and are great materials to work with.

 

[fishingguy12345]

What humidity level does it need to be? I've seen a few different opinions on it (some say 80%, some say 100%, etc)

60-80% is what we usually recommend. But chasing after a humidity number isn't a great idea. You want the surfaces to be wet after a misting and dry off about 2-3 hours after the misting.

 

[Erskine888]

I don't like local oak leaves as much as Southern Magnolia and Live Oak, but they can be used and might be a good choice for leucs (who might well be run dryer than all other dart species). Having leaves shipped to us is kind of crazy when you think about it, unless one lives in Antarctica or something where there are no other options. I like to microwave all my leaves before use (in an open Ziplok freezer bag, for one minute or until hot but not so hot the bag melts).

If you haven't yet, you might give some thought as to whether you want to use the styrofoam background. It won't play with plants very well, likely has places the frogs can get behind and freak you out, and it isn't really any better for climbing than glass (I'd guess; I toss those backgrounds and cover the back glass with contact paper so I can't see my wall).

I agree with your leaf choices, and would add seagrape leaves (although they can be pricey)...

 

[Erskine888]

I haven't had time to post until this weekend, I've been working a lot.
I have been working on my viv in my free time; it is planted and (unless my plants don't thrive) pretty much finished. It's not heavily planted, but it has a good sized brom, black rabbits foot, asparagus fern, an orchid (Phalaenopsis), peacock fern, and 2 others I can't remember of the names of off the top of my head.
It does still look a little sparse to me but I know the plants will fill out some though and I don't want to overdo it initially. I might add a few more later on if it still needs more in a couple of months after giving it a bit of a grow out period.
I'll post a photo later when I get home if I remember so y'all can critique it.

It's only been planted for 3-4 days, so I'm not sure if this will be an issue in the long run or if it's a temporary problem, but I'm struggling with keeping the humidity up. I have a reptizoo digital thermometer/hydrometer. The temp is a constant 75-76 in the day and drops to 70-71 at night.
I've been hand misting 2-3x a day and I'm worried about overwatering the plants.
The tank has a fully ventilated/mesh top. It has additional vents on the sides.

Is there too much ventilation to keep up the humidity?
What humidity level does it need to be? I've seen a few different opinions on it (some say 80%, some say 100%, etc)
I read on a few threads here that covering the mesh top could help. Is this the case?
If so, what would work best temporarily/as a test to see if/how much it would help? I have a friend that can/will cut a piece of glass to fit if need be.

I apologize if this is repetitive and/or I've missed the answers in my searches

In my experience, a fully-ventilated top causes a loss of humidity. If you cover a good amount of the venting (not completely, as you need adequate circulation), you will hold humidity without the substrate becoming soggy. You will be able to cut bqck on the amount of water used when you mist, and the plants will do much better. There will be an adjustment period, but the plants will adapt, and thrive. When I started my first vivs, I was way over-misting, and the plants (as well as the frogs, I assume) suffered. An overly soggy substrate will rot the roots. Play around with it a bit, and you will find a happy medium (pun intended).

 

[Socratic Monologue]

In some situations, reducing the amount of water per watering ('misting' can be misleading) session in order avoid 'soggy substrate' has caused issues for frogs (dehydration). A suitable substrate such as real ABG doesn't get soggy with any amount of water per session (though watering too frequently can cause issues for plants and frogs). Full saturation to the point of measurable flowthrough at least once a day is no problem for ABG (or turface, or calcium clay, or leaf litter on foam, or probably some others I'm missing). If a substrate can't play nice in rainforest conditions, then it may not be the right substrate for a dart viv.

The combination of targeting RH numbers and throttling misting duration has proven to lead to poor outcomes for frogs on occasion.

 

[Erskine888]

In some situations, reducing the amount of water per watering ('misting' can be misleading) session in order avoid 'soggy substrate' has caused issues for frogs (dehydration). A suitable substrate such as real ABG doesn't get soggy with any amount of water per session (though watering too frequently can cause issues for plants and frogs). Full saturation to the point of measurable flowthrough at least once a day is no problem for ABG (or turface, or calcium clay, or leaf litter on foam, or probably some others I'm missing). If a substrate can't play nice in rainforest conditions, then it may not be the right substrate for a dart viv.

The combination of targeting RH numbers and throttling misting duration has proven to lead to poor outcomes for frogs on occasion.

I think that you misunderstood my post. My point is that if you have a completely open screen top, you will have to overwater in order to retain humidity. This will lead to soggy conditions, no matter what substrate you are using (I use a high quality ABG mix myself).