Long-term pond tank

[ambertastic]

Taking inspiration from amkid247's pond tank experiment (http://www.caudata.org/forum/f1173-advanced-newt-salamander-topics/f6-vivaria-enclosures-product-reviews/f1182-outdoor-enclosures/60409-pond-tank.html), a little over a month ago I collected some frog eggs from a nearby pond to raise at home.
I started with a 20 gallon. I have pond muck as the substrate, about an inch thick at its deepest, though the 'terrain' is pretty varied. On top of that is a good layer of dead marsh grass/twigs. Finally, I filled the thing with pond water and added the eggs. It's absolutely thriving! I grabbed a few stalks of marsh grass initially but tons of new shoots have sprung up and the originals are twice as tall, hydra and micro-bugs abound, and my tadpoles are getting their legs. A few mosquitos have morphed out but that seems to be the worst of it as far as bugs go. I've also noticed some caddisfly larvae and two little black beetles. And lots of snails. It's been fascinating watching everyone go about their daily business, and so far all I've had to do is add new water (from the sink) every week.
Essentially, I adore this set up. After I release the frogs I would like to make it my Notophthalmus viridescens' permanent home - I would love to see him navigate a more interesting environment and maybe snack on REAL prey, depending on what's left in there (or what I add if I go for more pond water). My first concern is parasites/disease, but so far everything seems so healthy and wonderful. I haven't lost any tadpoles. No gross/dangerous insects. I believe the pond is fish-less but there might be some little ones - it's a big pond. My next concern is that the apparently flawless water chemistry will start to go downhill after a few months. There are no purely aquatic plants in the tank now but I have tons in other tanks that I could add to help keep things balanced.
Anyone have any input?

 

[Dcerdeiras]

That sounds cool.

I tried that once before I even took interest in amphibians. I had some fish in it, but after a few days they died and the habitat began to smell bad. Sounds like it is going well, but since you want to introduce some Notophthalmus viridescens' , I would suggest putting the aquarium near a sunny window or put a lamp over it to stimulate algae growth or even better, introduce some live plants such as duckweed or some submerged plants.

Good luck with your future plans, wish I had space for that!

 

[eyrops]

There are many things I like about your approach. I will certainly date myself with this explanation, but so be it. I grew up with library books that had instructions for making your own aquariums and stocking them from your neighborhood ponds. Although I also had access as a child to stores with basic tropical fish, your approach was and still remains my first love. I was always more interested in what was going on in my own pond or lake or stream than I was in exotics. I have had the opportunity to see some success in this, and I have also created some spectacular failures.
My most common failure was having the tank go anaerobic. I (unfortunately) have found many ways to do this. If the substrate uses a lot of oxygen to fuel the decomposition processes happening there, that can bring the system down. If you add a major living component and it dies, that also can bring the system down. If you don’t have some oxygen production by plants or algae, the system can go down even if it is lightly loaded with oxygen consumers. So you need some oxygen producers and you need light for them to be able to function. It helps a lot to have a little water circulation so that the water can pick up oxygen from the surface. I don’t regard sponge filters as cheating anymore. It helps a lot to load the tank lightly rather than heavily with animals for many reasons. Oxygen consumption is probably number one.
The other issue that causes major trouble is conflicting constraints. I tend to like the various creatures somewhat indiscriminately. I think hydras are cool. I love to watch a hydra grab a Daphnia. I enjoy watching the various aquatic insect larvae and adults. I realize, though, that if the goal is to raise tadpoles or salamander larvae the concept of enemies is very real. If a hydra is big enough to grab newly hatched larvae, it will do it. If not, it may grab the Daphnia or other food organisms before the larvae can. Dragonfly larvae or predaceous diving beetles or their larvae are big trouble. Giant waterbugs are trouble. The list becomes pretty long, and many of the bad actors are far from rare. So there is a strong argument to simplify and to exclude all unnecessary components if the main goal is to raise amphibians.
On a more positive note, I have been able to raise tadpoles of various sorts and also tiger salamander larvae in setups pretty much as you have described. I’ve also used outdoor pools that were vulnerable to some of the bad guys with some success. I wish you the best in your endeavors.