Hi tnoutlaw36 - well, when I started out years ago, I found it tough at times, too - every fish death was a major tragedy for an animal-loving kid...still not much better (I couldn't eat for days when my last dog died)! I think that its just about having plenty of plants in a reasonably fertile substrate and treating the plants the way they want to be treated - enough light, enough food - and preferably some additional C02 if you can run to it - if not, plants can still thrive without adding it, just not quite so spectacularly.
Remembering to feed the plants is key - running the tank long enough to get the plants properly started is helpful, although I have to say, I quickly added the zebra danios and 2 corys to my tank in this thread and even have just a plain old UG filter, but everyone is doing great. I have plenty of gravel depth (about 3-4 inches), which is important if using UG with live rooted plants. I often leave the lamp on for way too long, but there is so far not a trace of algae, maybe because the plants are consuming all of the liquid nutrients (both plant fertilizer and fish waste) and I don't overfeed the fish.
Today I finished setting up another 10G (in the kitchen), which I have approached differently. Again there is no direct sunlight falling on this tank.
This one I used a mixture of pool filter sand mixed with a lot of sphagnum peat for the substrate, which was soaked for several days to waterlog the peat, then I covered this with a layer of clean filter sand (you can buy this from a pools/spas or DIY center - quite cheap for a 50 pound bag and inert/clean - with no dust to speak of and as it is quartz, adds no hardness to the water). I mixed in 10ml of liquid ferts (API Leaf Zone) to the sand-peat mixture before adding the clean sand then started planting.
Filtration is a hang-on-back and apart from the heater, that's all there is in the tank, plus about $30.00 in plants. I have just started it up, so it looks very murky due to peat particles. I want to put maybe 6-8 serpae tetras and 2 to 4 corys in this one, because I think these species should like the chemical impact of the peat (on pH). I plan to let the plants/water settle for a week or two before adding fish. There are a few pond snails in here (see image - this one is about 1/4-inch long), so there will be some bioload. I also rinsed the new filter sponge, carbon and bio-colony material in water drawn from my first tank.
Lighting is 2 x 13w compact flourescent tubes set into a standard incendescent 10g hood. This is going to make the tank appear very brightly lit - if the water ever clears! Faster growing and broad-leaved plants will create areas of shade, so I will have to make sure the lower plants get enough light.
Filter is an Aqua Clear 20, plants are 1 Amazon Sword, several Cryptocoryne wendtii, 2 java ferns (which I intend to tie to a rock), 1 bunch of Ludwigia, Narrow Leaf (Ludwigia palustris), bunch of Hygrophilla difformis (wisteria), a bunch of rotala rotundifolia, 1 bunch of Telanthera Rosefolia (Alternanthera reineckii). I also have some of the hornwort in there from my first tank.
I know I will do some tweaking of layout as plants grow (or not), but the photos are just part of the time-series record of the success or failure of this aquarium setup. I will add CO2 within the next few days (I know, should have done it already...)
