Help! Random white/cloudiness in fully cycled tank

RobberyinCSharp1824 · Mar 24, 2015

I have a 20 gallon tank that has been fully cycled/established for about 11 months now. I have had a few up ups and downs getting phosphates under control recently, but otherwise, things have been very good for my tank. I do regular water changes once a week (although I will shamefully admit it's been once ever two weeks lately because I hurt my back pretty badly :frown: ).

Well, everything was just peachy in my tank today. I came home around 2pm and saw my tank - completely fine. Around 4pm my entire tank is extremely cloudy - much like you'd see in a bacterial bloom in new tanks. I felt the water and noticed that it feels almost slimy to the touch. I have no idea what this is, and although my coral/fish don't seem too distressed now, I would love to get some help finding out what this is and why it happened! I did notice that my clownfish and cardinal fish were hanging out around the top of the tank (normally they hang at the bottom) so I added an aerator to keep plenty of O2 circulating. I am also mixing some salt water right now for a serious water change.

Here are my parameters as of now:

pH: 7.8 (low, but has been constantly at this rate due to the low O2 exchange from keeping our house windows closed for winter)
Ammonia: 0
Nitrite: 0
Nitrate: 20ppm
Phosphate: 0.25ppm

And a photo of the situation:

Thoughts, everyone?

SeahorseKeeper · Mar 25, 2015

How is the tank doing?

RobberyinCSharp1824 · Mar 29, 2015

SeahorseKeeper said:
How is the tank doing?

Thank heavens the tank is doing well, but it did cost me my Cardinal Fish :( No idea where that came from. A few days and a water changed resolved the issue, but it is definitely one of the strangest things I've had happen in a long time.