So this took me a bit longer than I expected. My computer went down and life got otherwise busy, but I've still made some slow progress.
First, some pictures of the waterfall. After several more coats of grout I hit the whole thing with a couple coats of textured indoor spraypaint. This was followed by about 5 or 6 coats of clear acrylic to act as a general sealant, though I still have a couple tubes of silicone coming in to use in the water areas. I tested it with just the acrylic anyway and had only a few leaks, so I'm taking that as a good sign.
I have most of the components required for my auto-watering system. I talked to a sales rep at HorticultureSource.com and they recommended a air splitter that they felt would hold under the additional pressure. That will allow me to run a 1/2" line from a pump in a water bucket, up through the bottom of the terrarium where it will split into six 1/4" lines under the soil tray. These will run up the sides of the soil tray and top-water at the base of each plant. A timer will be connected to water for around 1 minute per day, I think.
Lighting is still up in the air. I cannot, for the life of me, find a hood that will fit in the space I have available. I have somewhere around 12” in length at 6” in height (or 13” in length at 5” high) and would like to keep the width to 8” or less. Most hoods clock in at 18" as a minimum. So I think I'm going to go to Home Depot, pickup a couple bases, and try to build a hood out of, I guess, aluminum foil...guess it's time to hit the internet for a tutorial on how to do that.
I'm excited about the progress, but also a little saddened by the timing. It will likely be September by the time I'm ready to order the plants in; almost time for them to go into dormancy. I'm almost tempted to wait until late winter and buy them then. Or am I remembering correctly that most plants sold online are younglings and probably okay skipping their first dormancy?
This is starting to look fantastic! I don't think you needed to layer the Great Stuff with quite so much sealant. A few layers of silicone is all that is necessary.
The reason I put so many layers of acrylic on is because of the size of the waterfall. If this were a large project where I could see into all the nooks and crannies of shallow lakes it wouldn't' be such a problem, but as it is there are areas in the lakebeds that I can hardly reach. I ran a water test after my first coat of silicone and found that there is apparently a rather large hole at the bottom of the middle lake. This isn't surprising to me; the little nub of the lake sticking out towards the front of the waterfall is so small that I simply cannot reach into it to seal; I'm trying to do it with a paintbrush.
Also, the great stuff was more of a modeling agent than a sealant. I didn't really use it underwater at all.
I came across something today that may have solved a little problem I've had since the beginning. Initially I wanted to try and find tiny little LEDs to hide within the waterfall for nightime lighting, but couldn't do so. I'm not sure the best way to include them even if I had, but I now have a much better idea. Had anyone here ever worked with bio-luminescence in a terrarium setting?
I did some Googling today. There are small organisms that can live in freshwater that bio-luminesce at night in response to water movement. I'm not sure what their nutritional requirements are, though, or how they'll interact with the pump. Has anyone used them in a waterfall before? That covers nighttime lighting in a much more natural way than LEDs and will look awesome.
Assuming it will work out I'm also considering getting some bio-luminescing mushrooms. I read that you start them on a log, but do they stay there? Or am I in danger of them overrunning the whole terrarium?
I'll certainly continue to research online, but I'd love to hear tips from personal experience.
I have no experience with the aquatic bio luminescent organisms. but as for the mushrooms i would leave those out of the terrarium, they will make short work out of any media in the terrarium, break it down. also with enough humidity they will grow on unintended areas such as your waterfall structure. also the fruiting bodies (mushrooms) are extremely short lived and will smell aweful as soon as they start to decompose
It's been a while, so I thought I'd post a quick update.
This project has been set back. After applying several coats of silicone my waterfall was still leaking in many places. I had used more porous Styrofoam than I should have. I had also made the lakes very deep and thus harder to reach into; this was especially problematic in the narrow passageways of the streams. The very small, 1/2 inch jutout in the mid lake was a big problem too. This prevented me from being able to properly cover and seal. In the end, I think I'm going to need to scrap this waterfall.
I'm looking at this as a learning opportunity more than a failure, and am getting ready to try again. This time I'm going to make shallower lakes, a flatter stream, and less intricacies. I also may avoid the expanding foam; This is for financial reasons as much as anything, though the foam did close off areas that I had wanted to be open. I'm going to try thick grout in place of the foam this time.
I've decided on a few improvements too. The stream will be shortened, as I could hardly fir the waterfall into the terrarium last time (between the measurement errors, expanding foam, and additions, it was about an inch longer than expected and the terrarium was smaller than expected). I'll also run the output tube up the back of the waterfall into a cave that will spill into the upper lake; this provides better sealing and a better appearance than just fountaining the water up the bottom of the lake. I'm going to get rid of the steps, too, I think, as they just didn't look good last time; though I may just move them to a lower tier.
Updates as events warrant.