I cannot stop my fish tank from turning cloudy. Please help, I've included some pictures inside.
Here's what my fish tank looks like a week or so after cleaning it with a gravel vaccum, changing 80% of the water, and installing a new filter (click each image for a larger copy):
I have a 20 gallon freshwater tropical tank, with a heater keeping the water between 78-80°F. I've had the tank for several months, but have always had this problem with cloudy water. It's gotten much worse lately, though.
I've got five little blue fish, two silver-dollar-like ones, one orange guy, a clown loach, and three little yellow guys. I used to have two snails, but they died. Perhaps relevant to the issue, the snail shells seemed to deteroirate over time in an unhealthy way. All of the plants are live, but I've gone through several. They seem to slowly turn translucent. The latest is that large plant - which is showing black splotches on its leaves now.
I've got an ammonia detector tag inside, which has never indicated a problem. I've got test strips for various stuff, and only ever see the nitrate go up a little, never to a dangerous amount. The pH is a little low, and I've never been able to get it up to 7.0 and have it stay there. For awhile I used pH adjustment drops, but lately have been trying this white buffer powder solution stuff. Still doesn't seem to help.
Please help me stabilize and clarify my fish tank. I'm not averse to paying for, let's say, a new type of filter (currently using the standard 4x3 carbon bag things), but I want to know what I need first. The local pet stores haven't been very helpful.