Galabar

The UV light in the canister filter should not affect the nitrifying bacteria on your filter media. The causes may have been some of the other things mentioned in this thread.

I'm not an expert, but it may be the case that there needs to be a certain concentration of a dechlorinator in order for it to work properly.

For a fish-in cycle, I would highly recommend water changes, probably daily to keep ammonia under 0.25.

You could also consider double sided tape along the back of the stand uprights.

I would nope out of that one. Wait for the next Craigslist deal (and be careful moving it). 🙂

I have bred the two together and have gotten some interesting results. However, I'm not a "fish scientist." So, I won't give an opinion on whether they are the same species... 🙂

chili rasboras Endler's guppies/livebearers

I would suggest getting that KH up. The nitrogen cycle consumes KH. A very low KH can lead to a pH swing. I'm not sure if that is the issue. However, that seems to be the thing that stands out.

Just a warning: I've never been able to keep neon tetras alive. I'm not sure, but I don't think it's my fault... 😉 On the flip side of that, my black neon tetras, ember tetras, and diamond tetras seem like they'll die of old age... 🙂

A canister filter with inline heating and CO2 would really clean up the look of that tank. I'm not saying that it doesn't look good now (it does). However, I'm imagining it without the heater or CO2 diffuser. :)

It looks like you are close. Just wait a couple of days to see if that ammonia goes to 0 (along with the nitrite). At this point, you can either wait or do a large water change and add fish. If you add fish, feed sparingly.

How are your plants growing? How big is your tank and what is it stocked with? You can encourage algae with slower growing plants and excess fertilizer (phosphate) and light (especially blue light). However, if algae starts growing on your rocks, it will probably also start growing on those slow growing plants. Also, if you have grazers like snails, otos, and SAEs, you can remove them from the tank. None of my planted tanks have any significant algae and that is probably true for most of us here with somewhat balanced tanks. So, growing algae might be a bit difficult (given that most of us are in your boat).

It could take up to 40 days for your nitrite level to go down to zero. Adding fish at this point (or ammonia) won't speed it up. The only way to speed it up (other than adding seasoned filter media) would have been to add the nitrite at the beginning. However, it's difficult to get nitrite and, unlike Dr. Tim's Ammonia, there isn't really a good, "packaged" version of nitrite to add to your tank. You should see your nitrite levels start to decrease in about a week.

I prefer two lights. With two lights, the fish are illuminated when they are at the front glass (and they are often at the front glass).

Found this: