I started a 6 gallon high tech planted tank last May. I've added and subtracted fish and shrimp in this tank but over the last 4 months the tank has housed 10 chili rasboras, 3 amanos, 2 neocaridinas and one crs shrimp.
Everyone was doing fine till last night. I came home and the water was milky. The best way to describe it is that it looks like fog as you can see the suspended particles swirling in it. All my rasboras were dead. Oddly enough, all the shrimp were still alive.
My first action was to test parameters. The ppm was spot on at 200 as always. There was a slight ammonia spike at 0.25ppm but far less than I expected. Nitrate and nitrite levels were at 0ppm and my ph was unchanged at 6.2. Temperature was right where it always is at 75 degrees.
Both filters were running and seemed fine with no reduction in flow. I have a hob filter that came with the tank and I run a small canister filter with a spray bar just to make sure I have adequate gas exchange.
I then preformed a 70% water change using RO and matching the parameters as always and I then added activated carbon to my hob filter which I don't normally use and turned in for the night.
This morning, the water is still cloudy. I removed the carbon and added some filter floss to the hob instead and the fog seems slightly diminished. All the shrimp are doing fine. They're active and seem normal.
I am at a loss as to what caused this as I am religious about water changes and maintenance and my wife makes fun of me on "water change Wednesdays". I am constantly checking parameters and have had no issues till now.
Does anyone have an idea as to what went wrong? Should I scrap the tank and start over? Needless to say I am very frustrated.