Big Nitrite Issue
So we've had a tank for a little over a month, 10G, that we got for my son for his 7th birthday (he's only responsible for remembering to feed them, he's 7, we're not going to make him do any sort of heavy maintenance). We had gotten him 3 neon tetras, but they seemed to be acting oddly so someone had suggested to me I get two more to get them up to schooling levels.
Now after I did this I discovered that 10G is too small for tetras period, let alone 5. I had been testing a couple times a week with test strips and our nitrate/nitrite levels were always extremely low. I'd been using API stress coat and quick start at water changes, but ever since I added the two new fish, approximately 20 hours now, the nitrite has gone way way up. Initially the five of them seemed to be schooling and were fine, but now they're darting around slamming into each other, it's very sad and frustrating.
Soooo... I know it's my fault, I messed up. My responsibility. Plan is to purchase a new 20G tank and set it up immediately and move the fishes over as soon as it's ready. I have two issues. One, today is a holiday therefore every single store in the universe is closed and I can't purchase anything. Two, we have limited supplies left. We're down to 1 test strip. We still have stress coat/quick start left, but nothing else with which to treat the water.
What can I do to safeguard my little beauties until I can get their new bigger home set up and ready, disregarding anything but keeping them healthy in the short term. I know changing too much water will destroy the bacteria in the tank, but that's a secondary concern as I feel like I'm killing them already.
Time/effort is not going to be a problem short term. If I need to keep constantly changing the water for the next three days, I can do it, I'm just looking for ways to keep them going.
Thanks in advance.