New tank syndrome/bloom - to change water or not? Tetras gasping?
So I was an idiot and put 5 female Bettas and 6 young neon tetra in my tank all at once. Please feel free to berate me for that. Anyways that was two days ago, and I've got the expected cloudy tank bloom thing going on. My Bettas are totally happy but the tetras are all at the top of the tank gulping/gasping, I feel terrible. I've got a good flow going from the pump, the temperature is 25°C. The water parameters are: ammonia 0ppm, nitrates 20ppm, nitrites 3ish ppm (I only have the testing strips, proper testing kit is coming in the post soon).
The fish keeper at the aquatics centre I got them from said that the bloom plus stress is 'new tank syndrome' and it will all calm down in a few days, and I shouldn't do any water changes as that will delay the bacteria sorting themselves out. But I can only assume the nitrates/nitrites are making it hard for the tetras to breathe, they weren't like this for the first 24hrs.
Any advice?
Edit: I don't currently have anywhere else to put the tetras