Murky water, wont go!

[Rodders]

I noticed my water start to go murky the other day and couldnt work out why.
By the morning it was near enough solid white, couldnt even see a fish.
It was a water change day anyway.
When i opened the top of my filter (fitted in the tank) one of my danios was dead in there, how he got in there i dont know?!?!?!?!?!
Is this the reason for my murky water.
I have changed 25% of the water and put a new carbon filter and pre filter in, but it doesnt really have seemed to have made much difference!?!?!

Help!?

 

[WILDER]

What are your test results in ammonia,nitrite,nitrate,and ph, has the tank cycled, the dead fish wouldn't help, do a water change, but test water before you change any water.

 

[Rodders]

Water tests are exactly the same as when the water was clear.
I've used Ammo Lock cause the Ammonia seemed to go up from 0. I've put it in a few times as directed and it didnt do it to start with. Would this have done it, its been about 1 week since i first put some in?

 

[WILDER]

Could of been, when did you last do a gravel vac, I would do a water change.

 

[Rodders]

I've been doing a bit of gravel vac when i change the water. But its never turned the water white. It gets a bit dirty but soon settles down.
This is like fog in a tank!

 

[RYO]

i had a similar prob , mine was down to using too much water conditioner(worth a check)

 

[Rodders]

All i put in my water is.

Stress coat
Water fresh-dechlorinator
Filter start, still reasonably new
Ammo lock, had a bit of a high reading

Thing is, its been fine every time i've put these things in so far.

About 6 days after a water change it started.

Will see what its like when i get home, hope i can see some fish and theres no more dead ones