Me too! It's been a pain to have all the water in there with the rocks but having to wait to get the rest of the equipment. I'd only planned on adding the plants for another few weeks, but my mom went back after I was done and got the fish for me. :/ I wish she'd gotten the driftwood pieces I'd been eyeing, but she didn't. I'm hoping everything will be okay though.
They're an assortment of fancy guppies and lyretails. I like them quite a bit, and was pointing them out to her which is why she got them for me. The store didn't carry koi swordtails or pencilfish thankfully lol
ETA
The tank looks ridiculously empty right now too lol. I may need to find some plants that will grow to be taller just to fill in the space at the back of the tank! Eventually I'd like to get a 3D background, but that's a long way out. I'm thinking I'm going to try to find a large piece of driftwood at the local fish store (lfs, I like that lol) and see what types of plants will root on it and grow like that.
Ok in terms of plants, if you want to go heavily planted you will definitely need to switch out the river rocks to something much smaller. You could throw some river rocks in intermittently, but if you wanted to go that route I would actually recommend picking several larger rocks and using them to create focal points in the tank. That would look more aesthetically pleasing, imo, than spreading around a bunch of small-medium sized rocks. An example of a few larger rocks would be like this:
http://i.imgur.com/nukug.jpg
http://www.stuworrallphotography.co.uk/images/ukaps/the_unknown.jpg
And here is an example with rock and driftwood:
http://www.projectaquarium.com/aqua...ages/small_planted_Tank_Genesis_hardscape.jpg
Now in terms of substrate, it depends on several factors. If you want to keep corydoras species, I really think sand is the only way to go. They love sifting through it and seem most happy with sand bottoms. However, sand is not ideal for plants. That being said, you can absolutely make it work. Here is a breakdown of your options as I see it.
Plant-Specific Substrate
Pros: looks good (imo), grows plants well
Cons: expensive, not ideal for sand-sifting species
Gravel
Pros: can grow plants ok, can look good (but can also look terrible lol), cheap
Cons: not good for sand-sifters, not ideal for plants
Sand
Pros: looks good (imo), great for sand-sifters
Cons: needs to be aerated, not ideal for plants
Personally, I went with the sand and the reason I did so was because having sand-sifting bottom fish was important to me AND because sand can be made suitable (like gravel) for plants with the addition of root tab fertilizers. They cost around $12-15 at an aquarium store and you can put them in the substrate to provide nutrients for the plants. The plant-specific substrates basically just have root tabs crushed and spread throughout them so you don't have to worry about feeding the roots. In order to make a decision here though, you have to decide what is important to you and then base your decision off that.
It's great that you have a test kit, and guppies are pretty tough fish so as long as you are diligent about keeping an eye on your ammonia, nitrites and nitrates you should be ok. Do you know how hard your tap water is? Guppies prefer water on the harder side and tend to die and waste away in soft water with a lack of minerals.
I agree with you, the tank would look really good with a big focal point. Just a heads up, if you want to do a background I really recommend doing it now before moving ahead with planting and putting in a new substrate. You have to have the tank completely dry and silicone the background to the glass, which then needs to dry for 48 hours. So that is a job you definitely don't want to do once your tank is established as you would essentially have to take the entire thing down and start again from scratch.
