To water his plants, but help keep humidity from getting too high I am going to mostly water from the "bottom up" The idea is that there is water is in the deeper layers of substrate like in nature and then dry as you reach the surface. Basically IME you want to keep the lower layers damp at all time. You never want the substrate to fully dry out... then plants die as well as the clean up crew and beneficial bacteria that keep the bad ones away.
To accomplish this I am using a watering spike like this one..
The spike was put in the cool side back where the substrate was the deepest. I put it all the way down to the drainage layer. You can take the cap off and pour some water in there and it will perculate the water to the bottom where it will eventually evaporate and wick upwards towards the surface toward the plant roots. This damp bottom also serves as a reservior of water to provide a consistent healthy humidity in the enclosure. When watering, less is more.. Don't saturated soil in the bottom. I find a moisture meter is very valuable when trying to find out "how much water do I need to water" a drainage layer helps add a margin of safety.
Wanting to make things easier instead of removing the cap once a week to water the substrate, I installed a black silicone airline hose with a Raindripper end on it. For those not familiar a raindripper is something used in gardening and you can get a small bag of them for a few bucks.
It has a barbed fitting that connects to end of the air hose and then it allows water to drip out slowly instead of just all at one time. I removed the cap and then just put the hose in there with this at the end. The cap has a nice cutout to make room for this purpose which is helpfull.
Then I run the hose to a reservior bucket above the enclosure. It can just site on top of the screen top, but in my case it is on a shelf above the enclosure. I used an old plastic deli cup that some feeders came in as my resevoir. I think it holds about 2 cups of water. I simply drilled a small hole in the bottom side of the plastic cup that is a little bit smaller than the airline tubing and then put the tubing through. It helps to cut the line at an angle to get it in there easier. I like the slicone hose as it makes a nice seal that doesn't leak if done correctly. It looks like this..
When it's time to water I just pour say a cup of water into the reservior and over a period of time it drains into the spike and down into bottom layers of substrate. I kept this low tech since this is a temp setup, but on my leopard gecko setup I'm using an old peristaltic dosing pump from my old aquarium to add water from a much larger 2 gallon container. This is less work as I only fill it up every month or so.
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