Let me add a few more details about my hydration system that may be useful to you. You will find a detailed description of how I mix the grout and vermiculite at Pictures of Formicariums and Outworlds - Page 41 - General Ant Keeping - Ants & Myrmecology Forum (formiculture.com) (If this doesn't work I apologize). I have posted a picture below of how I now use sponges to replace water towers. The first picture shows how I used a sponge in the outworld of a Tetramorium colony. The sponge in the foreground is the same as the one in the outworld, and the package they came in is in the background. I bought them at a Dollar Store and they are called absorbent cosmetic sponges.
They hold an amazing amount of water, in fact, you can see them swell as you fill them. I feel the inability of a water tower to supply water to the ants and hydrate the grout is a critical flaw in that system. You can see from the close-up that the ants are drinking from the sponge. I can tell when it's dry when I see many more ants desperately trying to get water. Although this isn't an example of a sponge being used inside the nest, you can imagine how you could position it and then put grout around it instead of a water tower.
Another advantage of the sponge is that when it's saturated, water flows out the bottom of the sponge, not over the top as it does in a water tower which can freak out some of my jittery colonies. I use a cotton pad on the bottom to link the sponge with an oasis in the outworld. The oasis is usually another piece of sponge covered in moss that is always kept moist.
This is a picture of a small founding formicarium where I put a sponge in the middle and tubes for nesting alongside it. Sponge is much more versatile because you can cut it to any shape and fit it into places where a water tower cannot go. I cover the whole thing with moss and when I hydrate the sponge, I just watch for water coming out the bottom and job done. I also use small pieces of the same kind of sponge to feed sugar/water and drinking water to all my colonies. They are so absorbent that they hold a lot while the ants can't drown in it. I also cut pieces to fit in a test tube and use them to replace a cotton plug when feeding sugar/water. Although they don't slide down the test tube like cotton sometimes does as the ants drink the water, it does conduct the sugar/water and ants can empty the tube.
When I start planning a new build, hydration is one of the main considerations. I have found that these sponges offer versatility in size and shape, hold an amazing amount of liquid, and not only humidify the nest but can also hydrate grout and provide water to the ants. I'm not sure if ANTdrew considers this directly hydrating a nest, but it seems to satisfy many of the needs of my ants.
RPT
