I have a little bit more time now. What you are doing sounds like a lot of fun. Good for you!
I keep overlooking that you are planning on raising your tads in an aquarium. What size aquarium do you have? The reason I ask is that I have a very small whisper pump for oxygenation in my pond. This type of a bubbler might create a problem in a smaller habitat such as an aquarium. Bubblers can result in death of older metamorphosing tadpoles. Tads can become bloated with air. They then float on the surface and die. It’s a type of gas disease. You might be better off hooking up a pump and a filter and forgoing a small bubbler. My other thoughts are that tads/frogs produce considerably more waste than a few goldfish so you will need a way to keep the water clean. I am really sorry but I missed the obvious which is that you are planning on doing this in an aquarium. I really think you’re going to have to hook up a pump and filter to keep their water clean because the water has to be changed to insure the health of your tads. I use biofilters but you don’t have time to get one of those up and running so perhaps you can seek help choosing a very basic filtration system from a local pet shop.
SunDoode reminded me of something. I forgot to mention that the spinach is offered out the gate. I add other food as the tads develolp. After about a week I add Wardley gold fish flakes. At about the 2nd to the 3rd week, I then purchase brine shrimp and begin offering that. My tad pond is outside in a woodland setting and my tads are treated to all kids of critters that go bump in the pond in addition to the algae. Most notably, mosquito larva. You might want to do a little research on the Internet and see what’s out there for aquarium raised tads. "More captive amphibians die from food-related problems than for any other reason. The most common problem is failure to offer suitable prey items, which vary from species to species. Lack of variety in the diet leading to metabolic deficiencies is also a common problem. Living prey should form the bulk of the diet for most species. Non-living "convenience foods" can form a useful part of the diet for some species but should never for the bulk of the diet for any species.” The boiled lettuce above sounds interesting, I'll have to try that.
Don't be worrying about dragonflies or damselflies. Your aquarium wasn't sitting outside last year. Me, I have to worry as I saw a few dragonflies ovipositing in my pond.
Later on after your tads morph please keep this in mind, frogs will eat smaller frogs just like some fish eat smaller fish. Heck, even smaller frogs will try to eat larger frogs. Frogs are a lot like dogs only they are more aggressive about “marking” their territory. There is a certain amount of hunting space that a frog will claim and if other frogs invade that space; they will be chased away, eaten, or beaten until they die or go away. It’s a frog eat frog world out there. I add these comments in the event your chose let them go their merry way. If you attempt to keep them all, you might have a froggie genocide on your hands.
If it is any consolation to you, I have had tremendous successes with tads. Mine all hop away though to "bluer pastures".
My single greatest struggle is keeping a big bullfrog from another pond of mine out of my tad pond. Big Bertha the bull frog likes to hang out around that pond waiting to see what hops out in front of her face. What an opportunist she is!
Here’s a neat link to a person who kept a journal.
http://aquaticfrogs.tripod.com/id30.html
I had saved this link for my kids but found that I thoroughly enjoyed it myself.