Adding more Fishes and a Stupid mistake

So bad three days. Of the three Harlequin Rasbora that I got three days ago, two are dead. One I am sure died because it was sick when we got it. Second, I am not sure if it died because of stress - since these are schooling fish and two are too few. Or if they died due to Ammonia poisoning. Ammonia tests showed very slight level of Ammonia, less than the lowest level the kit was designed to measure.

I suspected stress as the cause of death. The two fishes seemed scared and not at all at home in the aquarium, so today I decided to get 4 more of them to make the remaining one feel more at home. It seemed to go well, all 5 are now together and so much more active than before.

Now the stupid part. I also saw that all the plants were showing signs of dying, lots of leaves turning brown. I think this is because there is not enough nitrate in the water, so they are starving. The plant food only contains Potassium since Phosphorus and Nitrates come from waste. A new aquarium does not have waste. So I decided to add a little bit of 20-20-20 orchid fertilizer to the water. Bad Bad idea, ammonia shot up to 2 ppm. This is really bad for the fishes. I changed about 12 gallons of water. Lets see if they survive the night. At least for now, they seem to be happily swimming around.

Harlequin Rasbora