Cloudy water but water tests good

Question
I have had this 55 gallon tank set up for about 8 months.

First, we do have sulfur water. I never thought about treating it until ive tried everything else to fix this cloudy water. Its sort of a light white color. I asked the pet store about bacteria bloom but they said it wasn't because of the water tests. It's been cloudy so long that I dont think it would be that either? I have had many tanks before and never this problem. But also never sulfur water.

I've tried  
ACUREL F
ACCU CLEAR
ALGAFIX
STRESS COAT +

It did get very clear once, but for maybe a day lol.

We have about 15 fish right now. Most small to medium size. We did have about 20-22, most like teras and glowfish. But they have started to die off. So I want to figure out this cloudy water thing quickly!

I've had the water tested at 2 pet stores and they say nothing is wrong with the water.

We have good air flow (bubbles) and a penguin 350 filter. We have many live plants. Good T5 lighting.

I'm baffled and want clear water! :'(

Thanks for any help!

Answer
Jake,
Unfortunately all the chemicals listed do little to nothing to clear up cloudy water. If the chemicals are mixed together, this could be part of the problem. The first thing I would do is make sure the filter is working properly. Good air flow does not necessarily mean the filter is working. Even though the tank has been set up for 8 months, it could still be a bacteria bloom. Sometimes it can take months for this to happen. What are the Ph, ammonia, and nitrite levels in the water? Make sure, since you have live plants in the tank, that you remove any dead, dying, or decaying plants. This is contribute to cloudy water along with over feeding. When you do your weekly water change are you vacuuming the gravel? If so, remember to only clean about 1 inch of the gravel. Any lower will remove good bacteria.

White cloudy water is caused by an ammonia spike, bacterial blooms, faulty ornaments or added chemicals. Green haze is caused by algae colonies. I have included a good website with information on what causes the cloudy water and how to fix it.

http://www.helium.com/items/1219305-how-to-prevent-cloudy-water-in-an-aquarium-c